0001554855-21-000059 | 20-F | XBRL Viewer

Selling, general and administrative expenses

$ 5,146,734

$ 7,294,055

$ 7,658,588

Cost of sales

(4,087,317)

(5,107,495)

(5,279,300)

Gross profit

1,059,417

2,186,560

2,379,288

(1,119,227)

(1,365,974)

(1,509,976)

(Loss) income before equity in earnings of non-consolidated companies and income tax

(622,402)

Other operating income

33,393

23,004

15,059

Other operating expenses

(14,252)

(11,199)

(12,558)

Operating (loss) income

(663,071)

832,391

871,813

Finance income

18,387

47,997

39,856

Finance cost

(27,014)

(43,381)

(36,942)

Other financial results

(56,368)

14,667

34,386

(728,066)

851,674

909,113

Equity in earnings of non-consolidated companies

108,799

82,036

193,994

(Loss) income before income tax

(619,267)

933,710

1,103,107

Income tax

(23,150)

(202,452)

(229,207)

(Loss) income for the year

(642,417)

731,258

873,900

Attributable to:

Owners of the parent

(634,418)

742,686

876,063

Non-controlling interests

(7,999)

(11,428)

(2,163)

(Loss) income for the year

$ (642,417)

$ 731,258

$ 873,900

Earnings per share attributable to the owners of the parent during the year:

Weighted average number of ordinary shares (thousands) (in shares)

1,180,537

Continuing operations

Basic and diluted earnings (losses) per share (in dollars per share)

$ (0.54)

$ 0.63

$ 0.74

Basic and diluted earnings per ADS (U.S. dollars per ADS) (in dollars per share)

^[1]

$ (1.07)

$ 1.26

$ 1.48

[1]	Each ADS equals two shares.

CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2020

Dec. 31, 2019

Dec. 31, 2018

CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME

(Loss) income for the year

$ (642,417)

$ 731,258

$ 873,900

Items that may be subsequently reclassified to profit or loss:

Change in value of cash flow hedges and instruments at fair value

31,172

(27,294)

(96,916)

(9,832)

3,039

(6,701)

Income tax relating to components of other comprehensive income

2,376

(707)

- Currency translation adjustment

^[1]

(31,977)

(10,781)

1,848

- Changes in the fair value of derivatives held as cash flow hedges and others

792

812

(132)

Total other comprehensive income that will be reclassified to profit or loss, net of tax

(7,469)

(34,931)

(101,867)

Items that will not be reclassified to profit or loss:

Remeasurements of post employment benefit obligations

(4,971)

(9,272)

7,963

Income tax on items that will not be reclassified

770

1,545

(1,932)

Remeasurements of post employment benefit obligations of non-consolidated companies

634

(9,878)

(3,855)

Total other comprehensive income that will not be reclassified to profit or loss, net of tax

(3,567)

(17,605)

2,176

Other comprehensive (loss) for the year, net of tax

(11,036)

(52,536)

(99,691)

Non-controlling interests

(653,453)

678,722

774,209

Attributable to:

Owners of the parent

(643,435)

690,095

776,713

(10,018)

(11,373)

(2,504)

Balance (Previously stated) at Dec. 31, 2017

$ (653,453)

$ 678,722

$ 774,209

[1]

For 2018 and 2019 Tenaris recognized its share over the effects on the adoption of IAS 29, “Financial Reporting in Hyperinflationary Economies” by Ternium in other comprehensive income as a currency translation adjustment. In 2020 Ternium changed the functional currency of its Argentine subsidiary to U.S. dollar and IAS 29 is no longer applicable.

CONSOLIDATED STATEMENT OF FINANCIAL POSITION - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Non-current assets
Property, plant and equipment, net	$ 6,193,181	$ 6,090,017
Intangible assets, net	1,429,056	1,561,559
Right-of-use assets, net	241,953	233,126
Investments in non-consolidated companies	957,352	879,965
Other investments	247,082	24,934
Deferred tax assets	205,590	225,680
Receivables, net	154,303	157,103
Non-current assets	9,428,517	9,172,384
Current assets
Inventories, net	1,636,673	2,265,880
Receivables and prepayments, net	77,849	104,575
Current tax assets	136,384	167,388
Trade receivables, net	968,148	1,348,160
Derivative financial instruments	11,449	19,929
Other investments	872,488	210,376
Cash and cash equivalents	584,681	1,554,299
Current assets	4,287,672	5,670,607
Total assets	13,716,189	14,842,991
EQUITY
Capital and reserves attributable to owners of the parent	11,262,888	11,988,958
Non-controlling interests	183,585	197,414
Total equity	11,446,473	12,186,372
Non-current liabilities
Borrowings	315,739	40,880
Lease liabilities	213,848	192,318
Deferred tax liabilities	254,801	336,982
Other liabilities	245,635	251,383
Provisions	73,218	54,599
Non-current liabilities	1,103,241	876,162
Current liabilities
Borrowings	303,268	781,272
Lease liabilities	43,495	37,849
Derivative financial instruments	3,217	1,814
Current tax liabilities	90,593	127,625
Other liabilities	202,826	176,264
Provisions	12,279	17,017
Customer advances	48,692	82,729
Trade payables	462,105	555,887
Current liabilities	1,166,475	1,780,457
Total liabilities	2,269,716	2,656,619
Total equity and liabilities	$ 13,716,189	$ 14,842,991

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - USD ($)
$ in Thousands

Total

Share Capital

Legal Reserves

Share Premium

Currency Translation Adjustment

Other Reserves

Retained Earnings

Non-controlling interests

$ 11,580,970

$ 11,482,185

$ 1,180,537

^[1]

$ 118,054

$ 609,733

$ (824,423)

$ (320,569)

^[2]

$ 10,718,853

$ 98,785

Balance (Changes in accounting policies (Section II AP)) at Dec. 31, 2017

8,018

8,006

2,786

^[2]

5,220

Balance at Dec. 31, 2017

11,588,988

11,490,191

1,180,537

^[1]

118,054

609,733

(824,423)

(317,783)

^[2]

10,724,073

98,797

Income (loss) for the year

873,900

876,063

(2,163)

Remeasurements of post employment benefit obligations, net of taxes

(96,916)

(96,673)

(243)

6,031

6,135

^[2]

(104)

Change in value of instruments at fair value through other comprehensive income and cash flow hedges, net of taxes

(6,667)

(6,673)

^[2]

From other comprehensive income of non-consolidated companies

(2,139)

1,848

(3,987)

^[2]

Other comprehensive (loss) income for the year

(99,691)

(99,350)

(94,825)

(4,525)

^[2]

(341)

Acquisition and other changes in non-controlling interests

774,209

776,713

(94,825)

(4,525)

^[2]

876,063

(2,504)

^[3]

(24)

(2)

^[2]

(22)

Dividends paid in cash

(487,681)

(484,020)

(3,661)

Balance at Dec. 31, 2018

11,875,492

11,782,882

1,180,537

^[1]

118,054

609,733

(919,248)

(322,310)

^[2]

11,116,116

92,610

Income (loss) for the year

731,258

742,686

(11,428)

Remeasurements of post employment benefit obligations, net of taxes

(27,294)

(27,217)

(77)

(7,727)

(7,132)

^[2]

(595)

Change in value of instruments at fair value through other comprehensive income and cash flow hedges, net of taxes

2,332

1,605

^[2]

727

From other comprehensive income of non-consolidated companies

(19,847)

(10,781)

(9,066)

^[2]

Other comprehensive (loss) income for the year

(52,536)

(52,591)

(37,998)

(14,593)

^[2]

Acquisition and other changes in non-controlling interests

678,722

690,095

(37,998)

(14,593)

^[2]

742,686

(11,373)

^[3]

117,985

^[2]

117,984

Dividends paid in cash

(485,827)

(484,020)

(1,807)

Balance at Dec. 31, 2019

12,186,372

11,988,958

1,180,537

^[1]

118,054

609,733

(957,246)

(336,902)

^[2]

11,374,782

197,414

Income (loss) for the year

(642,417)

(634,418)

^[4]

(7,999)

Remeasurements of post employment benefit obligations, net of taxes

31,172

30,849

323

(4,201)

(4,236)

(4,664)

^[5]

428

^[4]

Change in value of instruments at fair value through other comprehensive income and cash flow hedges, net of taxes

(7,456)

(5,079)

^[5]

(2,377)

From other comprehensive income of non-consolidated companies

(30,551)

(31,977)

1,426

^[5]

Other comprehensive (loss) income for the year

(11,036)

(9,017)

(1,128)

(8,317)

^[5]

428

^[4]

(2,019)

Acquisition and other changes in non-controlling interests

(653,453)

(643,435)

(1,128)

(8,317)

^[5]

(633,990)

^[4]

(10,018)

^[6]

1,492

^[5]

1,490

Dividends paid in cash

(87,938)

(82,637)

^[4]

(5,301)

Balance at Dec. 31, 2020

$ 11,446,473

$ 11,262,888

$ 1,180,537

^[7]

$ 118,054

$ 609,733

$ (958,374)

$ (345,217)

^[5]

$ 10,658,155

^[4]

$ 183,585

[1]	The Company has an authorized share capital of a single class of 2.5 billion shares having a nominal value of $1.00 per share. As of December 31, 2019 and 2018 there were 1,180,536,830 shares issued. All issued shares are fully paid.
[2]	Other reserves include mainly the result of transactions with non-controlling interests that do not result in a loss of control, the remeasurement of post-employment benefit obligations and the changes in value of cash flow hedges and in available for sale financial instruments.
[3]	Mainly related to Saudi Steel Pipe Company (“SSPC”) acquisition. See note 32.
[4]	The restrictions to the distribution of profits and payment of dividends according to Luxembourg Law are disclosed in note 26 (iii).
[5]	Other reserves include mainly the result of transactions with non-controlling interests that do not result in a loss of control, the remeasurement of post-employment benefit obligations, the changes in value of cash flow hedges and the changes in financial instruments measured at fair value through other comprehensive income.
[6]	Mainly related to the agreement for the construction of Tenaris Baogang Baotou Steel Pipes Ltd. See note 34.
[7]	The Company has an authorized share capital of a single class of 2.5 billion shares having a nominal value of 1.00 per share. As of December 31, 2020 there were 1,180,536,830 shares issued. All issued shares are fully paid.

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY (Parentheticals) - $ / shares	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
CONSOLIDATED STATEMENT OF CHANGES IN EQUITY
Authorized share capital (in shares)	2,500,000,000	2,500,000,000	2,500,000,000
Nominal value (in dollars per share)	$ 1.00	$ 1.00	$ 1.00
Shares issued (in shares)	1,180,536,830	1,180,536,830	1,180,536,830

CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities
(Loss) income for the year	$ (642,417)	$ 731,258	$ 873,900
Adjustments for:
Depreciation and amortization	678,806	539,521	664,357
Impairment charge	622,402
Income tax accruals less payments	(117,214)	(193,417)	58,494
Equity in earnings of non-consolidated companies	(108,799)	(82,036)	(193,994)
Interest accruals less payments, net	(538)	(4,381)	6,151
Changes in provisions	(13,175)	2,739	(8,396)
Changes in working capital	1,059,135	523,109	(737,952)
Currency translation adjustment and others	42,183	11,146	(51,758)
Net cash provided by operating activities	1,520,383	1,527,939	610,802
Cash flows from investing activities
Capital expenditures	(193,322)	(350,174)	(349,473)
Changes in advance to suppliers of property, plant and equipment	(1,031)	3,820	4,851
Acquisition of subsidiaries, net of cash acquired	(1,025,367)	(132,845)
Investment in companies under cost method		(2,933)
Additions to associated companies		(19,610)
Loan to non-consolidated companies			(14,740)
Repayment of loan by non-consolidated companies		40,470	9,370
Proceeds from disposal of property, plant and equipment and intangible assets	14,394	2,091	6,010
Dividends received from non-consolidated companies	278	28,974	25,722
Changes in investments in securities	(887,216)	389,815	717,368
Net cash (used in) provided by investing activities	(2,092,264)	(40,392)	399,108
Cash flows from financing activities
Dividends paid	(82,637)	(484,020)	(484,020)
Dividends paid to non-controlling interest in subsidiaries	(5,301)	(1,872)	(3,498)
Changes in non-controlling interests	2	1	(24)
Payments of lease liabilities	(48,553)	(41,530)
Proceeds from borrowings	658,156	1,332,716	1,019,302
Repayments of borrowings	(896,986)	(1,159,053)	(1,432,202)
Net cash used in financing activities	(375,319)	(353,758)	(900,442)
(Decrease) increase in cash and cash equivalents	(947,200)	1,133,789	109,468
Movement in cash and cash equivalents
At the beginning of the year	1,554,275	426,717	330,090
Effect of exchange rate changes	(22,492)	(6,231)	(12,841)
(Decrease) increase in cash and cash equivalents	(947,200)	1,133,789	109,468
At December 31,	584,583	1,554,275	426,717
Cash and cash equivalents:
Cash and cash equivalents	$ 1,554,275	$ 426,717	$ 426,717

I. General Information	12 Months Ended
I. General Information	Dec. 31, 2020
Disclosure of General Information About Financial Statements [Abstract]
I. GENERAL INFORMATION	I. GENERAL INFORMATION Tenaris S.A. (the “Company”) was established as a public limited liability company (société anonyme) under the laws of the Grand-Duchy of Luxembourg on December 17, 2001. The Company holds, either directly or indirectly, controlling interests in various subsidiaries in the steel pipe manufacturing and distribution businesses. References in these Consolidated Financial Statements to “Tenaris” refer to the Company and its consolidated subsidiaries. A list of the principal Company’s subsidiaries is included in note 31 to these Consolidated Financial Statements. The Company’s shares trade on the Italian Stock Exchange and the Mexican Stock Exchange; the Company’s American Depositary Securities (“ADS”) trade on the New York Stock Exchange. These Consolidated Financial Statements were approved for issuance by the Company’s Board of Directors on February 24, 2021.

II. Accounting Policies

12 Months Ended

Dec. 31, 2020

Disclosure of Summary of Significant Accounting Policies [Abstract]

II. Accounting Policies

II. Accounting policies

The principal accounting policies applied in the preparation of these Consolidated Financial Statements are set out below. These policies have been consistently applied to all the years presented, unless otherwise stated.

A Basis of presentation

The Consolidated Financial Statements of Tenaris have been prepared in accordance with International Financial Reporting Standards (“IFRS”), as issued by the International Accounting Standards Board (“IASB”) and in accordance with IFRS as adopted by the European Union, under the historical cost convention, as modified by the revaluation of certain financial assets and liabilities (including derivative instruments) and plan assets at fair value. The Consolidated Financial Statements are, unless otherwise noted, presented in thousands of U.S. dollars (“$”).

Whenever necessary, certain comparative amounts have been reclassified to conform to changes in presentation in the current year.

The preparation of Consolidated Financial Statements in conformity with IFRS requires management to make certain accounting estimates and assumptions that might affect among others, the reported amounts of assets, liabilities, contingent assets and liabilities, revenues and expenses. Actual results may differ from these estimates. The main areas involving significant estimates or judgements are: impairment of goodwill and long-lived assets (note II.H); income taxes (note II.O); obsolescence of inventory (note II.J); loss contingencies (note II.Q); allowance for trade receivables (note II.K); defined benefit obligations (note II.P); business combinations (notes II.B, IV.32); useful lives of property, plant and equipment and other long-lived assets (notes II.E, II.F, II.H); property title ownership restriction (note 37). During the period there were no material changes in the significant accounting estimates.

Management has reviewed the Company’s exposure to the effects of the oil and gas crisis and the COVID-19 pandemic and their impact over its business, financial position and performance, monitoring the recognition of deferred tax assets, and their recoverability, impairment testing, financial risk management -in particular credit and liquidity risks- and the adequacy of its provisions for contingent liabilities. In the twelve-month period ended December 31, 2020, management conducted impairment tests and recorded impairment charges over certain long-lived assets. Refer to notes 5 and 39 for further information on impairment of assets and the impact of the oil and gas crisis and the COVID-19 pandemic.

(1) Accounting pronouncements applicable as from January 1, 2020 and relevant for Tenaris

IFRS 16 “Leases”, “COVID-19 - Related Rent Concessions”

The Company chose not to adopt the optional amendment to IFRS 16 “Leases”, “COVID-19 - Related Rent Concessions”. An assessment was conducted and the Company concluded that the impact was not material.

Other accounting pronouncements that became effective during 2020 have no material effect on the Company’s financial condition or results of operations.

B Group accounting

(1) Subsidiaries and transactions with non-controlling interests

Subsidiaries are all entities over which Tenaris has control. Tenaris controls an entity when it is exposed to, or has rights to, variable returns from its involvement with the entity and has the ability to affect those returns through its power over the entity. Subsidiaries are fully consolidated from the date on which control is exercised by the Company and are no longer consolidated from the date control ceases.

The acquisition method of accounting is used to account for the acquisition of subsidiaries by Tenaris. The cost of an acquisition is measured as the fair value of the assets transferred, equity instruments issued and liabilities incurred or assumed at the date of exchange. Acquisition-related costs are expensed as incurred. Identifiable assets acquired, liabilities and contingent liabilities assumed in a business combination are measured initially at their fair values at the acquisition date. Any non-controlling interest in the acquiree is measured either at fair value or at the non-controlling interest’s proportionate share of the acquiree’s net assets. The excess of the aggregate of the consideration transferred and the amount of any non-controlling interest in the acquiree over the fair value of the identifiable net assets acquired is recorded as goodwill. If this is less than the fair value of the net assets of the subsidiary acquired, the difference is recognized directly in the Consolidated Income Statement.

Contingent consideration is classified either as equity or as a financial liability. Amounts classified as a financial liability are subsequently remeasured to fair value with changes in fair value recognized in profit or loss.

If the business combination is achieved in stages, the acquisition date carrying value of the acquirer’s previously held equity interest in the acquiree is remeasured to fair value at the acquisition date. Any gains or losses arising from such remeasurement are recognized in profit or loss.

Transactions with non-controlling interests that do not result in a loss of control are accounted as transactions with equity owners of the Company. For purchases from non-controlling interests, the difference between any consideration paid and the relevant share acquired of the carrying value of net assets of the subsidiary is recorded in equity. Gains or losses on disposals to non-controlling interests are also recorded in equity.

When the Company ceases to have control or significant influence, any retained interest in the entity is remeasured to its fair value, with the change in carrying amount recognized in profit or loss. The fair value is the initial carrying amount for the purposes of subsequently accounting for the retained interest as an associate, joint venture or financial asset. In addition, any amounts previously recognized in other comprehensive income in respect of that entity are accounted for as if the group had directly disposed of the related assets or liabilities. This may mean that amounts previously recognized in other comprehensive income are reclassified to profit or loss.

Material intercompany transactions, balances and unrealized gains (losses) on transactions between Tenaris subsidiaries have been eliminated in consolidation. However, since the functional currency of some subsidiaries is its respective local currency, some financial gains (losses) arising from intercompany transactions are generated. These are included in the Consolidated Income Statement under Other financial results.

(2) Non-consolidated companies

Non-consolidated companies are all entities in which Tenaris has significant influence but not control, generally accompanying a shareholding of between 20% and 50% of the voting rights. Investments in non-consolidated companies (associated and joint ventures) are accounted for by the equity method of accounting and are initially recognized at cost. The Company’s investment in non-consolidated companies includes goodwill identified in acquisition, net of any accumulated impairment loss.

Under the equity method of accounting, the investments are initially recognized at cost and adjusted thereafter to recognize Tenaris’s share of the post-acquisition profits or losses of the investee in profit or loss, and Tenaris’s share of movements in other comprehensive income of the investee in other comprehensive income. Dividends received or receivable from associates and joint ventures are recognized as a reduction in the carrying amount of the investment.

If material, unrealized results on transactions between Tenaris and its non-consolidated companies are eliminated to the extent of Tenaris’s interest in the non-consolidated companies. Unrealized losses are also eliminated unless the transaction provides evidence of an impairment indicator of the asset transferred. Financial statements of non-consolidated companies have been adjusted where necessary to ensure consistency with IFRS.

(2) Non-consolidated companies (Cont.)

The Company’s pro-rata share of earnings in non-consolidated companies is recorded in the Consolidated Income Statement under Equity in earnings of non-consolidated companies. The Company’s pro-rata share of changes in other comprehensive income is recognized in the Consolidated Statement of Comprehensive Income.

Ternium

At December 31, 2020, Tenaris held 11.46% of Ternium S.A (“Ternium”)’s common stock. The following factors and circumstances evidence that Tenaris has significant influence (as defined by IAS 28, “Investments in associates companies and Joint Ventures”) over Ternium, and as a result the Company’s investment in Ternium has been accounted for under the equity method:

Both the Company and Ternium are under the indirect common control of San Faustin S.A. (“San Faustin”);
Four out of eight members of Ternium’s Board of Directors (including Ternium’s Chairman) are also members of the Company’s Board of Directors;
Under the shareholders’ agreement by and between the Company and Techint Holdings S.à r.l, a wholly owned subsidiary of San Faustin and Ternium’s main shareholder, dated January 9, 2006, Techint Holdings S.à.r.l, is required to take actions within its power to cause (a) one of the members of Ternium’s Board of Directors to be nominated by the Company and (b) any director nominated by the Company to be only removed from Ternium’s Board of Directors pursuant to previous written instructions of the Company.

Usiminas

At December 31, 2020, Tenaris held, through its Brazilian subsidiary Confab Industrial S.A. (“Confab”), 36.5 million ordinary shares and 1.3 million preferred shares of Usinas Siderúrgicas de Minas Gerais S.A. - Usiminas (“Usiminas”), representing 5.19% of its shares with voting rights and 3.07% of its total share capital.

Confab’s acquisition of the Usiminas shares was part of a larger transaction performed on January 16, 2012, pursuant to which Tenaris’s affiliate Ternium (through certain of its subsidiaries) and Confab acquired a large block of Usiminas ordinary shares and joined Usiminas’ existing control group. Subsequently, in 2016, Ternium and Confab subscribed to additional ordinary shares and to preferred shares.

At December 31, 2020, the Usiminas control group held, in the aggregate, 483.6 million ordinary shares bound to the Usiminas shareholders’ agreement, representing approximately 68.6% of Usiminas’ voting capital. The Usiminas control group, which is bound by a long-term shareholders’ agreement that governs the rights and obligations of Usiminas’ control group members, is currently composed of three sub-groups: the T/T Group, comprising Confab and certain Ternium entities; the NSC Group, comprising Nippon Steel Corporation (“NSC”), Metal One Corporation and Mitsubishi Corporation; and Usiminas’ pension fund Previdência Usiminas. The T/T Group holds approximately 47.1% of the total shares held by the control group (39.5% corresponding to the Ternium entities and the other 7.6% corresponding to Confab); the NSC Group holds approximately 45.9% of the total shares held by the control group; and Previdência Usiminas holds the remaining 7%.

The corporate governance rules reflected in the Usiminas shareholders agreement include, among others, an alternation mechanism for the nomination of each of the Chief Executive Officer (“CEO”) and the Chairman of the board of directors of Usiminas, as well as a mechanism for the nomination of other members of Usiminas’ executive board. The Usiminas shareholders agreement also provides for an exit mechanism consisting of a buy-and-sell procedure—exercisable at any time after November 16, 2022 and applicable with respect to shares held by NSC and the T/T Group—, which would allow either Ternium or NSC to purchase all or a majority of the Usiminas shares held by the other shareholder.

Confab and the Ternium entities party to the Usiminas shareholders agreement have a separate shareholders agreement governing their respective rights and obligations as members of the T/T Group. Such separate agreement includes, among others, provisions granting Confab certain rights relating to the T/T Group’s nomination of Usiminas’ officers and directors under the Usiminas shareholders agreement. Those circumstances evidence that Tenaris has significant influence over Usiminas, and consequently, Tenaris accounts for its investment in Usiminas under the equity method (as defined by IAS 28).

Techgen

Techgen S.A. de C.V. (“Techgen”), which operates an electric power plant in Mexico, is a joint venture company owned 48% by Ternium, 30% by Tecpetrol International S.A. (“Tecpetrol”) and 22% by Tenaris. Tenaris, Ternium and Tecpetrol are parties to a shareholders’ agreement relating to the governance of Techgen. The Company, Ternium and Tecpetrol are under the indirect common control of San Faustin; consequently, Tenaris accounts its interest in Techgen under the equity method (as defined by IAS 28).

Global Pipe Company

Global Pipe Company (“GPC”) is a Saudi-German joint venture, established in 2010 and located in Jubail, Saudi Arabia, which manufactures LSAW pipes. Tenaris, through its subsidiary Saudi Steel Pipe Company (“SSPC”), currently owns 35% of the share capital of GPC. Through the shareholders agreement, SSPC is entitled to choose one of the five members of the Board of Directors of GPC. In addition, SSPC has the ability to block any shareholder resolution. Based on the facts stated above, the Company has determined that it has significant influence over this entity and accounts for its investment in GPC under the equity method (as defined by IAS 28).

Tenaris carries its investments in non consolidated companies under the equity method, with no additional goodwill or intangible assets recognized. Tenaris reviews investments in non-consolidated companies for impairment whenever events or changes in circumstances indicate that the asset’s carrying amount may not be recoverable. At December 31, 2020, 2019 and 2018, no impairment provisions were recorded in any of the aforementioned investments. See note 13.

C Segment information

The Company is organized in one major business segment, Tubes, which is also the reportable operating segment.

The Tubes segment includes the production and sale of both seamless and welded steel tubular products and related services mainly for the oil and gas industry, particularly oil country tubular goods (“OCTG”) used in drilling operations, and for other industrial applications with production processes that consist in the transformation of steel into tubular products. Business activities included in this segment are mainly dependent on the oil and gas industry worldwide, as this industry is a major consumer of steel pipe products, particularly OCTG used in drilling activities. Demand for steel pipe products from the oil and gas industry has historically been volatile and depends primarily upon the number of oil and natural gas wells being drilled, completed and reworked, and the depth and drilling conditions of these wells. Sales are generally made to end users, with exports being done through a centrally managed global distribution network and domestic sales are made through local subsidiaries. Corporate general and administrative expenses have been allocated to the Tubes segment.

Others includes all other business activities and operating segments that are not required to be separately reported, including the production and selling of sucker rods, industrial equipment, coiled tubing, utility conduits for buildings, heat exchangers, energy and raw materials that exceed internal requirements.

Tenaris’s Chief Operating Decision Maker (“CODM”) holds monthly meetings with senior management, in which operating and financial performance information is reviewed, including financial information that differs from IFRS principally as follows:

The use of direct cost methodology to calculate the inventories, while under IFRS it is at full cost, including absorption of production overheads and depreciations;
The use of costs based on previously internally defined cost estimates, while, under IFRS, costs are calculated at historical cost;
Other timing differences, if any.

Tenaris presents its geographical information in five areas: North America, South America, Europe, Middle East and Africa and Asia Pacific. For purposes of reporting geographical information, net sales are allocated to geographical areas based on the customer’s location; allocation of assets, capital expenditures and associated depreciations and amortizations are based on the geographical location of the assets.

D Foreign currency translation

(1) Functional and presentation currency

IAS 21 (revised), “The effects of changes in foreign exchange rates” defines the functional currency as the currency of the primary economic environment in which an entity operates.

The functional and presentation currency of the Company is the U.S. dollar. The U.S. dollar is the currency that best reflects the economic substance of the underlying events and circumstances relevant to Tenaris’s global operations.

Except for the Brazilian and Italian subsidiaries whose functional currencies are their local currencies, Tenaris determined that the functional currency of its other subsidiaries is the U.S. dollar, based on the following principal considerations:

Sales are mainly negotiated, denominated and settled in U.S. dollars. If priced in a currency other than the U.S. dollar, the sales price may consider exposure to fluctuation in the exchange rate versus the U.S. dollar;
Prices of their critical raw materials and inputs are priced and / or settled in U.S. dollars;
Transaction and operational environment and the cash flow of these operations have the U.S. dollar as reference currency;
Significant level of integration of the local operations within Tenaris’s international global distribution network;
Net financial assets and liabilities are mainly received and maintained in U.S. dollars;
The exchange rate of certain legal currencies has long-been affected by recurring and severe economic crises.

(2) Transactions in currencies other than the functional currency

Transactions in currencies other than the functional currency are translated into the functional currency using the exchange rates prevailing at the date of the transactions or valuation where items are re-measured.

At the end of each reporting period: (i) monetary items denominated in currencies other than the functional currency are translated using the closing rates; (ii) non-monetary items that are measured in terms of historical cost in a currency other than the functional currency are translated using the exchange rates prevailing at the date of the transactions; and (iii) non-monetary items that are measured at fair value in a currency other than the functional currency are translated using the exchange rates prevailing at the date when the fair value was determined.

Foreign exchange gains and losses resulting from the settlement of such transactions and from the translation at year-end exchange rates of monetary assets and liabilities denominated in currencies other than the functional currency are recorded as gains and losses from foreign exchange and included in Other financial results in the Consolidated Income Statement, except when deferred in equity as qualifying cash flow hedges and qualifying net investment hedges.

(3) Translation of financial information in currencies other than the functional currency

Results of operations for subsidiaries whose functional currencies are not the U.S. dollar are translated into U.S. dollars at the average exchange rates for each quarter of the year. Financial statement positions are translated at the year-end exchange rates. Translation differences are recognized in a separate component of equity as currency translation adjustments. In the case of a sale or other disposal of any of such subsidiaries, any accumulated translation difference would be recognized in income as a gain or loss from the sale.

Goodwill and fair value adjustments arising from the acquisition of a foreign operation are treated as assets and liabilities of the foreign operation and translated at the closing rate.

E Property, plant and equipment

Property, plant and equipment are recognized at historical acquisition or construction cost less accumulated depreciation and impairment losses. Historical cost includes expenditure that is directly attributable to the acquisition of the items. Property, plant and equipment acquired through acquisitions accounted for as business combinations have been valued initially at the fair market value of the assets acquired.

Major overhaul and rebuilding expenditures are capitalized as property, plant and equipment only when it is probable that future economic benefits associated with the item will flow to the Company and the investment enhances the condition of assets beyond its original condition. The carrying amount of the replaced part is derecognized. Maintenance expenses on manufacturing properties are recorded as cost of products sold in the year in which they are incurred.

Cost may also include transfers from equity of any gains or losses on qualifying cash flow hedges of foreign currency purchases of property, plant and equipment.

Borrowing costs that are attributable to the acquisition or construction of certain capital assets are capitalized as part of the cost of the asset, in accordance with IAS 23(R), “Borrowing Costs”. Assets for which borrowing costs are capitalized are those that require a substantial period of time to prepare for their intended use.

The depreciation method is reviewed at each year end. Depreciation is calculated using the straight-line method to depreciate the cost of each asset to its residual value over its estimated useful life, as follows:

	Land	No Depreciation
	Buildings and improvements	30-50 years
	Plant and production equipment	10-40 years
	Vehicles, furniture and fixtures, and other equipment	4 -10 years

The assets’ residual values and useful lives of significant plant and production equipment are reviewed and adjusted, if appropriate, at each year-end date. An asset’s carrying amount is written down immediately to its recoverable amount if the asset’s carrying amount is greater than its estimated recoverable amount.

Management’s re-estimation of assets useful lives, performed in accordance with IAS 16, “Property, Plant and Equipment”, resulted in additional depreciation expenses for 2020 of $45 million and did not materially affect depreciation expenses for 2019 and 2018.

Tenaris depreciates each significant part of an item of property, plant and equipment for its different production facilities that (i) can be properly identified as an independent component with a cost that is significant in relation to the total cost of the item, and (ii) has a useful operating life that is different from another significant part of that same item of property, plant and equipment.

Gains and losses on disposals are determined by comparing the proceeds with the carrying amount of assets and are recognized under Other operating income or Other operating expenses in the Consolidated Income Statement.

F Intangible assets

(1) Goodwill

Goodwill represents the excess of the acquisition cost over the fair value of Tenaris’s share of net identifiable assets acquired as part of business combinations determined mainly by independent valuations. Goodwill is tested at least annually for impairment and carried at cost less accumulated impairment losses. Impairment losses on goodwill are not reversed. Goodwill is included in the Consolidated Statement of Financial Position under Intangible assets, net.

For the purpose of impairment testing, goodwill is allocated to a cash generating unit (“CGU”) or group of CGUs that are expected to benefit from the business combination which generated the goodwill being tested.

(2) Information systems projects

Costs associated with maintaining computer software programs are generally recognized as an expense as incurred. However, costs directly related to the development, acquisition and implementation of information systems are recognized as intangible assets if it is probable that they have economic benefits exceeding one year and comply with the recognition criteria of IAS 38, “Intangible Assets”.

Information systems projects recognized as assets are amortized using the straight-line method over their useful lives, generally not exceeding a period of 3 years. Amortization charges are mainly classified as Selling, general and administrative expenses in the Consolidated Income Statement.

Management’s re-estimation of assets useful lives, performed in accordance with IAS 38, resulted in additional amortization expenses for 2020 of $11.1 million and did not materially affect amortization expenses for 2019 and 2018.

(3) Licenses, patents, trademarks and proprietary technology

Licenses, patents, trademarks, and proprietary technology acquired in a business combination are initially recognized at fair value at the acquisition date. Licenses, patents, proprietary technology and those trademarks that have a finite useful life are carried at cost less accumulated amortization. Amortization is calculated using the straight-line method to allocate the cost over their estimated useful lives, and does not exceed a period of 10 years. Amortization charges are mainly classified as Selling, general and administrative expenses in the Consolidated Income Statement.

The balance of acquired trademarks that have indefinite useful lives according to external appraisal amounts to $86.7 million at December 31, 2020, 2019 and 2018, and are included in Hydril CGU. Main factors considered in the determination of the indefinite useful lives include the years that they have been in service and their recognition among customers in the industry.

Management’s re-estimation of assets useful lives, performed in accordance with IAS 38, did not materially affect amortization expenses for 2020, 2019 and 2018.

(4) Research and development

Research expenditures as well as development costs that do not fulfill the criteria for capitalization are recorded as Cost of sales in the Consolidated Income Statement as incurred. Research and development expenditures included in Cost of sales for the years 2020, 2019 and 2018 totaled $41.8 million, $61.1 million and $63.4 million, respectively.

Capitalized costs were not material for the years 2020, 2019 and 2018.

(5) Customer relationships

In accordance with IFRS 3, "Business Combinations" and IAS 38, Tenaris has recognized the value of customer relationships separately from goodwill attributable to the acquisition of Maverick Tube Corporation (“Maverick”) and Hydril Company (“Hydril”) groups, as well as the more recent acquisitions of Saudi Steel Pipes (“SSPC”) and Ipsco Tubulars Inc. (“IPSCO”).

Customer relationships acquired in a business combination are recognized at fair value at the acquisition date, have a finite useful life and are carried at cost less accumulated amortization. Amortization is calculated using the straight line method over the initial expected useful life of approximately 14 years for Maverick, 10 years for Hydril, 9 years for SSPC and 3 years for IPSCO.

In 2018 the Company reviewed the useful life of Maverick’s Tubes customer relationships and decided to reduce the remaining useful life from 2 years to zero, consequently a higher amortization charge of approximately $109 million was recorded in the Consolidated Income Statement under Selling, general and administrative expenses for the year ended December 31, 2018.

As of December 31, 2020 the net book value of IPSCO’s customer relationship amounts to $51.3 with a residual life of 2 years, SSPC’s customer relationship amounts to $63.8 million, with a residual useful life of 7 years, while Maverick’s and Hydril’s customer relationships are fully amortized.

Management’s re-estimation of assets useful lives, performed in accordance with IAS 38, did not materially affect amortization expenses for 2020 and 2019.

G Right-of-use assets and lease liabilities

Leases are recognized as a right-of-use asset and a corresponding liability at the date at which the leased asset is available for use by the group. Each lease payment is allocated between the liability and finance cost. The finance cost is charged to profit or loss over the lease period so as to produce a constant periodic rate of interest on the remaining balance of the liability for each period. The right-of-use asset is depreciated over the lease term on a straight-line basis.

Lease liabilities include the net present value of i) fixed payments, less any lease incentives receivable, ii) variable lease payments that are based on an index or a rate, iii) amounts expected to be payable by the lessee under residual value guarantees, iv) the exercise price of a purchase option if the lessee is reasonably certain to exercise that option, and v) payments of penalties for terminating the lease, if the lease term reflects the lessee exercising that option.

The lease payments are discounted using the interest rate implicit in the lease. If that rate cannot be determined, the lessee’s incremental borrowing rate is used, being the rate that the lessee would have to pay to borrow the funds necessary to obtain an asset of similar value in a similar economic environment with similar terms and conditions.

Right-of-use assets are measured at cost comprising the amount of the initial measurement of lease liability, any lease payments made at or before the commencement date less any lease incentives received and any initial direct costs incurred by the lessee.

Payments associated with short-term leases and leases of low-value assets are recognized on a straight-line basis as expenses in profit or loss. Short-term leases are leases with a lease term of 12 months or less.

In determining the lease term, management considers all facts and circumstances that create an economic incentive to exercise an extension option, or not exercise a termination option. Extension options (or periods after termination options) are only included in the lease term if the lease is reasonably certain to be extended (or not terminated).

H Impairment of non-financial assets

Long-lived assets including identifiable intangible assets are reviewed for impairment at the lowest level for which there are separately identifiable cash flows (CGU). Most of the Company’s principal subsidiaries that constitute a CGU have a single main production facility and, accordingly, each of such subsidiaries represents the lowest level of asset aggregation that generates largely independent cash inflows.

Assets that are subject to amortization or depreciation are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. Intangible assets with indefinite useful lives, including goodwill, are subject to at least an annual impairment test. Or more frequently if events or circumstances indicate that the carrying amount value may be impaired.

In assessing whether there is any indication that a CGU may be impaired, external and internal sources of information are analyzed. Material facts and circumstances specifically considered in the analysis usually include the discount rate used in Tenaris’s cash flow projections and the business condition in terms of competitive and economic factors, such as the cost of raw materials, oil and gas prices, capital expenditure programs for Tenaris’s customers and the evolution of the rig count.

An impairment loss is recognized for the amount by which the asset’s carrying amount exceeds its recoverable amount. The recoverable amount is the higher between the asset’s value in use and fair value less costs of disposal. Any impairment loss is allocated to reduce the carrying amount of the assets of the CGU in the following order:

(a) first, to reduce the carrying amount of any goodwill allocated to the CGU; and

(b) then, to the other assets of the unit (group of units) pro-rata on the basis of the carrying amount of each asset in the unit (group of units), considering not to reduce the carrying amount of the asset below the highest of its fair value less cost of disposal, its value in use or zero.

For purposes of calculating the fair value less costs of disposal, Tenaris uses the estimated value of future cash flows that a market participant could generate from the corresponding CGU.

Management judgment is required to estimate discounted future cash flows. Actual cash flows and values could vary significantly from the forecasted future cash flows and related values derived using discounting techniques.

Non-financial assets other than goodwill that suffered an impairment are reviewed for possible reversal at each reporting date. For more information on impairment charges see note 5.

I Other investments

Other investments consist primarily of investments in financial instruments and time deposits with a maturity of more than three months at the date of purchase.

Certain non-derivative financial assets that the Company held not for trading have been categorized as financial assets “at fair value through other comprehensive income” (“FVOCI”). They are carried at fair value and interest income from these financial assets is included in finance income using the effective interest rate method. Unrealized gains or losses are recorded as a fair value adjustment in the Consolidated Statement of Comprehensive Income and transferred to the Consolidated Income Statement when the financial asset is sold. Exchange gains and losses and impairments related to the financial assets are immediately recognized in the Consolidated Income Statement. FVOCI instruments with maturities greater than 12 months after the balance sheet date are included in non-current assets.

Other investments in financial instruments and time deposits are categorized as financial assets “at fair value through profit or loss” (“FVPL”) because such investments are held for trading and their performance is evaluated on a fair value basis. The results of these investments are recognized in Financial Results in the Consolidated Income Statement.

Purchases and sales of financial investments are recognized as of their settlement date.

The fair values of quoted investments are generally based on current bid prices. If the market for a financial investment is not active or the securities are not listed, Tenaris estimates the fair value by using standard valuation techniques. See Section III Financial Risk Management.

J Inventories

Inventories are stated at the lower between cost and net realizable value. The cost of finished goods and goods in process is comprised of raw materials, direct labor, utilities, freights and other direct costs and related production overhead costs, and it excludes borrowing costs. The allocation of fixed production costs, including depreciation and amortization charges, is based on the normal level of production capacity. Inventories cost is mainly based on the FIFO method. Tenaris estimates net realizable value of inventories by grouping, where applicable, similar or related items. Net realizable value is the estimated selling price in the ordinary course of business, less any estimated costs of completion and selling expenses. Goods in transit as of year-end are valued based on the supplier’s invoice cost.

Tenaris establishes an allowance for obsolete or slow-moving inventories related to finished goods, goods in process, supplies and spare parts. For slow moving or obsolete finished products, an allowance is established based on management’s analysis of product aging. An allowance for obsolete and slow-moving inventory of supplies and spare parts is established based on management's analysis of such items to be used as intended and the consideration of potential obsolescence due to technological changes, aging and consumption patterns.

K Trade and other receivables

Trade and other receivables are recognized initially at fair value that corresponds to the amount of consideration that is unconditional unless they contain significant financing components. The Company holds trade receivables with the objective to collect the contractual cash flows and therefore measures them subsequently at amortized cost using the effective interest method. Due to the short-term nature, their carrying amount is considered to be the same as their fair value.

Tenaris applies the IFRS 9 “Financial Instruments” simplified approach to measure expected credit losses, which uses a lifetime expected loss allowance for all trade receivables. To measure the expected credit losses, trade receivables have been grouped based on shared credit risk characteristics and the days past due. The expected loss rates are based on the payment profiles of sales over a period of three years and the corresponding historical credit losses experienced within this period. The expected loss allowance also reflects current and forward-looking information on macroeconomic factors affecting the ability of each customer to settle the receivables.

L Cash and cash equivalents

Cash and cash equivalents are comprised of cash at banks, liquidity funds and short-term investments with a maturity of less than three months at the date of purchase which are readily convertible to known amounts of cash. Assets recorded in cash and cash equivalents are carried at fair market value or at historical cost which approximates fair market value.

In the Consolidated Statement of Financial Position, bank overdrafts are included in Borrowings in current liabilities.

For the purposes of the Consolidated Statement of Cash Flows, Cash and cash equivalents includes overdrafts.

M Equity

(1) Equity components

The Consolidated Statement of Changes in Equity includes:

The value of share capital, legal reserve, share premium and other distributable reserves calculated in accordance with Luxembourg law;
The currency translation adjustment, other reserves, retained earnings and non-controlling interest calculated in accordance with IFRS.

(2) Share capital

The Company has an authorized share capital of a single class of 2.5 billion shares having a nominal value of $1.00 per share. Total ordinary shares issued and outstanding as of December 31, 2020, 2019 and 2018 are 1,180,536,830 with a par value of $1.00 per share with one vote each. All issued shares are fully paid.

(3) Dividends distribution by the Company to shareholders

Dividends distributions are recorded in the Company’s financial statements when Company’s shareholders have the right to receive the payment, or when interim dividends are approved by the Board of Directors in accordance with the by-laws of the Company.

Dividends may be paid by the Company to the extent that it has distributable retained earnings, calculated in accordance with Luxembourg law. See note 26 (iii).

N Borrowings

Borrowings are recognized initially at fair value net of transaction costs incurred and subsequently measured at amortized cost. Any difference between the proceeds (net of transaction costs) and the redemption amount is recognized in profit or loss over the period of the borrowings using the effective interest method.

O Current and deferred income tax

The income tax expense or credit for the period is the tax payable on the current period’s taxable income based on the applicable income tax rate for each jurisdiction adjusted by changes in deferred tax assets and liabilities attributable to temporary differences and to unused tax losses. Tax is recognized in the Consolidated Income Statement, except for tax items recognized in other comprehensive income or directly in equity.

The current income tax charge is calculated on the basis of the tax laws enacted or substantively enacted at the reporting date in the countries where the Company’s subsidiaries operate and generate taxable income. Management periodically evaluates positions taken in tax returns with respect to situations in which applicable tax regulations are subject to interpretation and establishes provisions when appropriate.

Deferred income tax is recognized applying the liability method on temporary differences arising between the tax bases of assets and liabilities and their carrying amounts in the financial statements. The temporary differences arise mainly from the effect of currency translation on depreciable fixed assets and inventories, depreciation on property, plant and equipment, valuation of inventories, provisions for pension plans and fair value adjustments of assets acquired in business combinations. Deferred tax assets are also recognized for net operating loss carry-forwards. Deferred tax assets and liabilities are measured at the tax rates that are expected to apply in the time period when the asset is realized or the liability is settled, based on tax laws that have been enacted or substantively enacted at the reporting date.

Management periodically evaluates positions taken in tax returns with respect to situations in which applicable tax regulation is subject to interpretation and considers whether it is probable that a taxation authority will accept an uncertain tax treatment. The Company measures its tax balances either based on the most likely amount or the expected value, depending on which method provides a better prediction of the resolution of the uncertainty.

Deferred tax assets are recognized to the extent that it is probable that future taxable income will be available against which the temporary differences can be utilized. At the end of each reporting period, Tenaris reassesses unrecognized deferred tax assets. Tenaris recognizes a previously unrecognized deferred tax asset to the extent that it has become probable that future taxable income will allow the deferred tax asset to be recovered.

Deferred tax liabilities and assets are not recognized for temporary differences between the carrying amount and tax basis of investments in foreign operations where the company is able to control the timing of the reversal of the temporary differences and it is probable that the differences will not reverse in the foreseeable future.

Deferred tax assets and liabilities are offset when there is a legally enforceable right to offset current tax assets and liabilities and when the deferred tax balances relate to the same taxation authority. Current tax assets and tax liabilities are offset where the entity has a legally enforceable right to offset and intends either to settle on a net basis, or to realize the asset and settle the liability simultaneously.

Deferred tax assets and liabilities are re-measured if tax rates change. These amounts are charged or credited to the Consolidated Income Statement or to the item Other comprehensive income for the year in the Consolidated Statement of Comprehensive Income, depending on the account to which the original amount was charged or credited.

P Employee benefits

(1) Short-term obligations

Liabilities for wages and salaries are recognized in respect of employees’ services up to the end of the reporting period and are measured at the amounts expected to be paid when the liabilities are settled. The liabilities are presented as current employee benefit obligations in the balance sheet.

(2) Post employment benefits

The Company has defined benefit and defined contribution plans. A defined benefit plan is a pension plan that defines an amount of pension benefit that an employee will receive on retirement, usually dependent on one or more factors such as age, years of service and compensation.

The liability recognized in the statement of financial position in respect of defined benefit pension plans is the present value of the defined benefit obligation at the end of the reporting period less the fair value of plan assets, if any. The defined benefit obligation is calculated annually (at year end) by independent actuaries using the projected unit credit method. The present value of the defined benefit obligation is determined by discounting the estimated future cash outflows using interest rates of high-quality corporate bonds that are denominated in the currency in which the benefits will be paid, and that have terms to maturity approximating to the terms of the related pension obligation.

Remeasurement gains and losses arising from experience adjustments and changes in actuarial assumptions are charged or credited to equity in Other comprehensive income in the period in which they arise. Past-service costs are recognized immediately in the Income Statement.

(2) Post employment benefits (Cont.)

For defined benefit plans, net interest income / expense is calculated based on the surplus or deficit derived by the difference between the defined benefit obligations less fair value of plan assets. For defined contribution plans, the Company pays contributions to publicly or privately administered pension insurance plans on a mandatory, contractual or voluntary basis. The Company has no further payment obligations once the contributions have been paid. The contributions are recognized as employee benefit expenses when they are due. Prepaid contributions are recognized as an asset to the extent that a cash refund or a reduction in the future payments is available.

Tenaris sponsors funded and unfunded defined benefit pension plans in certain subsidiaries. The most significant are:

An unfunded defined benefit employee retirement plan for certain senior officers. The plan is designed to provide certain benefits to those officers (additional to those contemplated under applicable labor laws) in case of termination of the employment relationship due to certain specified events, including retirement. This unfunded plan provides defined benefits based on years of service and final average salary. As of December 31, 2020 the outstanding liability for this plan amounts to $36.9 million.

Employees’ service rescission indemnity: the cost of this obligation is charged to the Consolidated Income Statement over the expected service lives of employees. This provision is primarily related to the liability accrued for employees at Tenaris’s Italian subsidiary. As from January 1, 2007 as a consequence of a change in an Italian law, employees were entitled to make contributions to external funds, thus, Tenaris’s Italian subsidiary pays every year the required contribution to the funds with no further obligation. As a result, the plan changed from a defined benefit plan to a defined contribution plan effective from that date, but only limited to the contributions of 2007 onwards. As of December 31, 2020 the outstanding liability for this plan amounts to $17.3 million.

Funded retirement benefit plan held in the US for the benefit of some employees hired prior a certain date, frozen for the purposes of credited service as well as determination of final average pay for the retirement benefit calculation. Plan assets consist primarily of investments in equities and money market funds. Additionally, an unfunded postretirement health and life plan is present that offers limited medical and life insurance benefits to the retirees, frozen to new participants. As of December 31, 2020 the outstanding liability for these plans amounts to $13.6 million.

Funded retirement benefit plans held in Canada for salary and hourly employees hired prior to a certain date based on years of service and, in the case of salaried employees, final average salary. Plan assets consist primarily of investments in equities and money market funds. Both plans were replaced for defined contribution plans. Effective June 2016 the salary plan was frozen for the purposes of credited service as well as determination of final average pay. As of December 31, 2020 the outstanding liability for this plan amounts to $10.6 million.

(3) Other long term benefits

During 2007, Tenaris launched an employee retention and long term incentive program (the “Program”) applicable to certain senior officers and employees of the Company, who will be granted a number of Units throughout the duration of the Program. The value of each of these Units is based on Tenaris’s shareholders’ equity (excluding non-controlling interest). Also, the beneficiaries of the Program are entitled to receive cash amounts based on (i) the amount of dividend payments made by Tenaris to its shareholders, and (ii) the number of Units held by each beneficiary to the Program. Until 2017 units were vested ratably over a period of four years and were mandatorily redeemed by the Company ten years after grant date, with the option of an early redemption at seven years after the grant date. Since 2018 units are vested ratably over the same period and are mandatorily redeemed by the Company seven years after grant date. The payment of the benefit is tied to the book value of the shares, and not to their market value. Tenaris valued this long-term incentive program as a long term benefit plan as classified in IAS 19, “Employee Benefits”.

As of December 31, 2020 and 2019, the outstanding liability corresponding to the Program amounts to $82.4 million and $99.0 million, respectively. The total value of the units granted (vested and unvested) to date under the program, considering the number of units and the book value per share as of December 31, 2020 and 2019, is $108.7 million and $119.9 million, respectively.

(4) Termination benefits

Termination benefits are payable when employment is terminated by Tenaris before the normal retirement date, or when an employee accepts voluntary redundancy in exchange for these benefits. Tenaris recognizes termination benefits at the earlier of the following dates: (a) when it can no longer withdraw the offer of those benefits; and (b) when the costs for a restructuring that is within the scope of IAS 37 and involves the payment of terminations benefits. In the case of an offer made to encourage voluntary redundancy, the termination benefits are measured based on the number of employees expected to accept the offer.

(5) Other compensation obligations

Employee entitlements to annual leave, long-service leave, sick leave and other bonuses and compensations obligations are accrued as earned.

Compensation to employees in the event of dismissal is charged to income in the year in which it becomes payable.

Q Provisions

Tenaris is subject to various claims, lawsuits and other legal proceedings, including customer claims, in which a third party is seeking payment for alleged damages, reimbursement for losses or indemnity. Tenaris’s potential liability with respect to such claims, lawsuits and other legal proceedings cannot be estimated with certainty. Management periodically reviews the status of each significant matter and assesses potential financial exposure. If, as a result of past events, a potential loss from a claim or proceeding is considered probable and the amount can be reliably estimated, a provision is recorded. Accruals for loss contingencies reflect a reasonable estimate of the losses to be incurred based on information available to management as of the date of preparation of the financial statements, and take into consideration Tenaris’s litigation and settlement strategies. These estimates are primarily constructed with the assistance of legal counsel. As the scope of liabilities become better defined, there may be changes in the estimates of future costs which could have a material adverse effect on its results of operations, financial condition and cash flows.

If Tenaris expects to be reimbursed for an accrued expense, as would be the case for an expense or loss covered under an insurance contract, and reimbursement is considered virtually certain, the expected reimbursement is recognized as a receivable.

This note should be read in conjunction with note 26.

R Trade and other payables

Trade and other payables are recognized initially at fair value, generally the nominal invoice amount and subsequently measured at amortized cost. They are presented as current liabilities unless payment is not due within twelve months after the reporting period. Due to the short-term nature their carrying amounts are considered to be the same as their fair value.

S Revenue recognition

Revenue comprises the fair value of the consideration received or receivable for the sale of goods and rendering of services in the ordinary course of Tenaris’s activities. The revenue recognized by the Company is measured at the transaction price of the consideration received or receivable to which the Company is entitled to, reduced by estimated returns and other customer credits, such as discounts and volume rebates, based on the expected value to be realized and after eliminating sales within the group.

Revenue is recognized at a point in time or over time from sales when control has been transferred and there is no unfulfilled performance obligation that could affect the acceptance of the product by the customer. The control is transferred upon delivery. Delivery occurs when the products have been shipped to the specific location, the risks of obsolescence and loss have been transferred and either the customer has accepted the product in accordance with the sales contract, the acceptance provisions have lapsed or the Company has objective evidence that all criteria for acceptance have been satisfied, including all performance obligations. These conditions are determined and analyzed on a contract by contract basis to ensure that all performance obligations are fulfilled. In particular, Tenaris verifies customer acceptance of the goods, the satisfaction of delivery terms and any other applicable condition.

For bill and hold transactions revenue is recognized only to the extent that (a) the reason for the bill and hold arrangement must be substantive (for example, the customer has requested the arrangement); (b) the products have been specifically identified and are ready for delivery; (c) the Company does not have the ability to use the product or to direct it to another customer; (d) the usual payment terms apply.

The Company’s contracts with customers do not provide any material variable consideration, other than discounts, rebates and right of return. Discounts and rebates are recognized based on the most likely value and rights of return are based on expected value considering past experience and contract conditions.

Where the contracts include multiple performance obligations, the transaction price is allocated to each performance obligation based on the stand-alone selling prices. Where these are not directly observable, they are estimated based on the expected cost plus margin.

There are no judgements applied by management that significantly affect the determination of timing of satisfaction of performance obligations, nor the transaction price and amounts allocated to different performance obligations.

Tenaris provides services related to goods sold, which represent a non-material portion of sales revenue and mainly include:

Pipe Management Services. This comprises mainly preparation of the pipes ready to be run, delivery to the customer, storage services and rig return.

Field Services. Comprises field technical support and running assistance.

These services are rendered in connection to the sales of goods and are attached to contracts with customers for the sale of goods. A significant portion of service revenue is recognized in the same period as the goods sold. There are no distinct uncertainties in the revenues and cash flows of the goods sold and services rendered as they are included in the same contract, have the same counterparty and are subject to the same conditions.

Revenue from providing services is recognized over time in the accounting period in which the services are rendered. The following inputs and outputs methods are applied to recognize revenue considering the nature of service:

Storage services, the Company provides storage services in owned or third-party warehouses, subject to a variable fee to be invoiced. This fee is determined based on the time that the customer maintains the material in the warehouse and the amount of the material stored. In the majority of cases, to quantify the amount to be invoiced in any given month, the monthly average fee of storage per ton is multiplied by the monthly average stock stored (in tons).

Freights, the Company recognized the revenue on a pro rata bases considering the units delivered and time elapsed.

Field services, the revenue is recognized considering output methods, in particular surveys of service completion provided by the customer.

The Company does not expect to have any contracts where the period between the transfer of the promised goods or services to the customer and payment by the customer exceeds one year. As a consequence, considering that the contracts do not include any significant financing component, the Company does not adjust any of the transaction prices for the time value of money. For this reason, the Company is also applying the practical expedient not to disclose details on transaction prices allocated to the remaining performance obligations as of the end of the reporting period.

Tenaris only provides standard quality warranties assuring that the goods sold will function as expected or are fit for their intended purpose, with no incremental service to the customer. Accordingly, warranties do not constitute a separate performance obligation.

Other revenues earned by Tenaris are recognized on the following basis:

Interest income: on the effective yield basis.
Dividend income from investments in other companies: when Tenaris’s right to receive payment is established.
Construction contracts revenues is recognized in accordance with the stage of the project completion.

T Cost of sales and other selling expenses

Cost of sales and other selling expenses are recognized in the Consolidated Income Statement on the accrual basis of accounting.

Commissions, freights and other selling expenses, including shipping and handling costs, are recorded in Selling, general and administrative expenses in the Consolidated Income Statement.

U Earnings per share

Earnings per share are calculated by dividing the income attributable to owners of the parent by the daily weighted average number of common shares outstanding during the year.

There are no dilutive potential ordinary shares.

V Financial instruments

Non derivative financial instruments comprise investments in financial debt instruments and equity, time deposits, trade and other receivables, cash and cash equivalents, borrowings and trade and other payables.

The Company classifies its financial instruments according to the following measurement categories:

those to be measured subsequently at fair value (either through OCI or through profit or loss), and
those to be measured at amortised cost.

The classification depends on the Company’s business model for managing the financial assets and contractual terms of the cash flows.

Financial assets are recognized on their settlement date. Financial assets are derecognized when the rights to receive cash flows from the financial assets have expired or have been transferred and the Company has transferred substantially all the risks and rewards of ownership.

At initial recognition, the Company measures a financial asset at its fair value plus, in the case of a financial asset not at fair value through profit or loss, transaction costs that are directly attributable to the acquisition of the financial asset. Transaction costs of financial assets carried at fair value through profit or loss are expenses in profit or loss.

Subsequent measurement of debt instruments depends on the Company’s business model for managing the asset and the cash flow characteristics of the asset. There are three measurement categories into which the Company classifies its debt instruments:

Amortized Cost: Assets that are held for collection of contractual cash flows where those cash flows represent solely payments of principal and interest. Interest income from these financial assets is included in finance income using the effective interest rate method.

Exchange gains and losses and impairments related to the financial assets are immediately recognized in the Consolidated Income Statement.

Fair value through other comprehensive income: Assets that are held for collection of contractual cash flows and for selling the financial assets, where the assets’ cash flows represent solely payments of principal and interest. Interest income from these financial assets is included in finance income using the effective interest rate method. Unrealized gains or losses are recorded as a fair value adjustment in the Consolidated Statement of Comprehensive Income and transferred to the Consolidated Income Statement when the financial asset is sold.

Fair value through profit and loss: Assets that do not meet the criteria for amortized cost or FVOCI. Changes in fair value of financial instruments at FVPL are immediately recognized in the Consolidated Income Statement.

For equity instruments, these are subsequently measured at fair value.

Accounting for derivative financial instruments and hedging activities is included within the Section III, Financial Risk Management.

III. Financial Risk Management

12 Months Ended

Dec. 31, 2020

Disclosure of detailed information about financial instruments [abstract]

III. FINANCIAL RISK MANAGEMENT

iii. Financial risk management

The multinational nature of Tenaris’s operations and customer base exposes the Company to a variety of risks, mainly related to market risks (including the effects of changes in foreign currency exchange rates and interest rates), credit risk and capital market risk. In order to manage the volatility related to these exposures, management evaluates exposures on a consolidated basis, taking advantage of exposure netting. The Company or its subsidiaries may then enter into various derivative transactions in order to prevent potential adverse impacts on Tenaris’s financial performance. Such derivative transactions are executed in accordance with internal policies and hedging practices.

A. Financial Risk Factors

(i) Capital Risk Management

Tenaris seeks to maintain a low debt to total equity ratio considering the industry and the markets where it operates. The year-end ratio of debt to total equity (where “debt” comprises financial borrowings and “total equity” is the sum of financial borrowings and equity) is 0.05 as of December 31, 2020 and 0.06 as of December 31, 2019. The Company does not have to comply with regulatory capital adequacy requirements.

(ii) Foreign exchange risk

Tenaris manufactures and sells its products in a number of countries throughout the world and consequently is exposed to foreign exchange rate risk. Since the Company’s functional currency is the U.S. dollar the purpose of Tenaris’s foreign currency hedging program is mainly to reduce the risk caused by changes in the exchange rates of other currencies against the U.S. dollar.

Tenaris’s exposure to currency fluctuations is reviewed on a periodic and consolidated basis. A number of derivative transactions are performed in order to achieve an efficient coverage in the absence of operative or natural hedges. Almost all of these transactions are forward exchange rates contracts. See note 25.

Tenaris does not enter into derivative financial instruments for trading or other speculative purposes, other than non-material investments in structured products.

In the case of subsidiaries with functional currencies other than the U.S. dollar, the results of hedging activities, reported in accordance with IFRS, may not reflect entirely the management’s assessment of its foreign exchange risk hedging program. Intercompany balances between Tenaris’s subsidiaries may generate financial gains (losses) to the extent that functional currencies differ.

The value of Tenaris’s financial assets and liabilities is subject to changes arising from the variation of foreign currency exchange rates. The following table provides a breakdown of Tenaris’s main financial assets and liabilities (including foreign exchange derivative contracts) which impact the Company’s profit and loss as of December 31, 2020 and 2019.

All amounts Long / (Short) in thousands of U.S. dollars	As of December 31,
Currency Exposure / Functional currency	2020			2019
Argentine Peso / U.S. dollar		(39,561	)		(95,811	)
Euro / U.S. dollar		(291,362	)		(103,518	)
Saudi Arabian Riyal / U.S. dollar		(125,789	)		(107,582	)

The main relevant exposures correspond to:

Argentine Peso / U.S. dollar

As of December 31, 2020 and 2019 consisting primarily of Argentine Peso-denominated financial, trade, social and fiscal payables at certain Argentine subsidiaries whose functional currency is the U.S. dollar. A change of 1% in the ARS/USD exchange rate would have generated a pre-tax gain / loss of $0.4 million and $1.0 million as of December 31, 2020 and 2019 respectively.

(ii) Foreign exchange risk (Cont.)

Euro / U.S. dollar

As of December 31, 2020 and 2019, consisting primarily of Euro-denominated intercompany liabilities at certain subsidiaries whose functional currency is the U.S. dollar. A change of 1% in the EUR/USD exchange rate would have generated a pre-tax gain / loss of $2.9 million and $1.0 million as of December 31, 2020 and 2019, respectively, which would have been to a large extent offset by changes in currency translation adjustment included in Tenaris’s net equity position.

Saudi Arabian Riyal / U. S. dollar

As of December 31, 2020 and 2019 consisting primarily of Saudi Arabian Riyal-denominated financial and trade payables. The Saudi Arabian Riyal is tied to the dollar.

Considering the balances held as of December 31, 2020 on financial assets and liabilities exposed to foreign exchange rate fluctuations, Tenaris estimates that the impact of a simultaneous 1% appreciation / depreciation movement in the levels of foreign currencies exchange rates relative to the U.S. dollar, would be a pre-tax gain / loss of $5.1 million (including a loss / gain of $1.0 million due to foreign exchange derivative contracts), which would be partially offset by changes to Tenaris’s net equity position of $2.3 million. For balances held as of December 31, 2019, a simultaneous 1% favorable / unfavorable movement in the foreign currencies exchange rates relative to the U.S. dollar, would have generated a pre-tax gain / loss of $4.6 million (including a loss / gain of $4.9 million due to foreign exchange derivative contracts), which would have been partially offset by changes to Tenaris’s net equity position of $0.6 million.

The Company entered into foreign exchange derivative contracts to mitigate the exposure to fluctuations in exchange rates.

(iii) Interest rate risk

Tenaris is subject to interest rate risk on its investment portfolio and its debt. The Company uses a mix of variable and fixed rate debt in combination with its investment portfolio strategy. The Company may choose to enter into foreign exchange derivative contracts and / or interest rate swaps to mitigate the exposure to changes in the interest rates.

The following table summarizes the proportions of variable-rate and fixed-rate debt as of each year end.

		As of December 31,
		2020			2019
	Amount in thousands of U.S. dollars		%	Amount in thousands of U.S. dollars		%
Fixed rate (*)		237,320	38%		768,002	93%
Variable rate		381,687	62%		54,150	7%
Total		619,007			822,152

(*) Out of the $237 million fixed rate borrowings, $197 million are short-term.

The Company estimates that, if market interest rates applicable to Tenaris’s borrowings had been 100 basis points higher, then the additional pre-tax loss would have been $7.1 million in 2020 and $7.7 million in 2019.

(iv) Credit risk

Credit risk arises from cash and cash equivalents, deposits with banks and financial institutions, as well as credit exposures to customers, including outstanding receivables and committed transactions. The Company also actively monitors the creditworthiness of its treasury, derivative and insurance counterparties in order to minimize its credit risk.

There is no significant concentration of credit risk from customers. No single customer comprised more than 10% of Tenaris’s net sales in 2020, 2019 and 2018.

(iv) Credit risk (Cont.)

Tenaris’s credit policies related to sales of products and services are designed to identify customers with acceptable credit history and to allow Tenaris to require the use of credit insurance, letters of credit and other instruments designed to minimize credit risks whenever deemed necessary. Tenaris maintains allowances for impairment for potential credit losses. See Section II.K.

As of December 31, 2020 and 2019 trade receivables amounted to $968.1 million and $1,348.2 million respectively. Trade receivables have guarantees under credit insurance of $134.9 million and $178.7 million, letter of credit and other bank guarantees of $47.8 million and $55.2 million, and other guarantees of $8.8 million and $0.6 million as of December 31, 2020 and 2019 respectively.

As of December 31, 2020 and 2019, overdue trade receivables amounted to $195.9 million and $242.7 million, respectively. As of December 31, 2020 and 2019, overdue guaranteed trade receivables amounted to $20.7 million and $28.7 million; and the allowance for doubtful accounts amounted to $53.7 million and $48.8 million respectively. Both the allowance for doubtful accounts and the existing guarantees are sufficient to cover doubtful trade receivables.

(v) Counterparty risk

Tenaris has investment guidelines with specific parameters to limit issuer risk on marketable securities. Counterparties for derivatives and cash transactions are limited to high credit quality financial institutions, normally investment grade.

Approximately 88% of Tenaris’s liquid financial assets corresponded to Investment Grade-rated instruments as of December 31, 2020, in comparison with approximately 96% as of December 31, 2019.

(vi) Liquidity risk

Tenaris financing strategy aims to maintain adequate financial resources and access to additional liquidity. During 2020, Tenaris has counted on cash flows from operations as well as additional bank financing to fund its transactions.

Management maintains sufficient cash and marketable securities to finance normal operations and believes that Tenaris also has appropriate access to market for short-term working capital needs.

Liquid financial assets as a whole (comprising cash and cash equivalents and other investments) were 12% of total assets at the end of 2020 and 2019.

Tenaris has a conservative approach to the management of its liquidity, which consists of i) cash and cash equivalents (cash in banks, liquidity funds and investments with a maturity of less than three months at the date of purchase), and ii) other investments (fixed income securities, time deposits, and fund investments).

Tenaris holds primarily investments in money market funds and variable or fixed-rate securities from investment grade issuers. As of December 31, 2020 and 2019, Tenaris does not have direct exposure to financial instruments issued by European sovereign counterparties.

Tenaris holds its investments primarily in U.S. dollars. As of December 31, 2020 and 2019, U.S. dollar denominated liquid assets plus investments denominated in other currencies hedged to the U.S. dollar represented approximately 95% of total liquid financial assets.

(vii) Commodity price risk

In the ordinary course of its operations, Tenaris purchases commodities and raw materials that are subject to price volatility caused by supply conditions, political and economic variables and other factors. As a consequence, Tenaris is exposed to risk resulting from fluctuations in the prices of these commodities and raw materials. Tenaris fixes the prices of such raw materials and commodities for short-term periods, typically not in excess of one year, in general Tenaris does not hedge this risk.

B. Category of financial instruments and classification within the fair value hierarchy

As mentioned in note II.A, the Company classifies its financial instruments in the following measurement categories: amortized cost, fair value through other comprehensive income and fair value through profit and loss. For financial instruments that are measured in the statement of financial position at fair value, IFRS 13, “Fair value measurement” requires a disclosure of fair value measurements by level according to the following fair value measurement hierarchy:

Level 1 - Quoted prices (unadjusted) in active markets for identical assets or liabilities.

Level 2 - Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly (that is, as prices) or indirectly (that is, derived from prices).

Level 3 - Inputs for the asset or liability that are not based on observable market data (that is, unobservable inputs).

The following tables present the financial instruments by category and levels as of December 31, 2020 and 2019.

(all amounts in thousands of U.S. dollars)

	Carrying Amount		Measurement Categories						At Fair Value
December 31, 2020	Carrying Amount		Amortized Cost		FVOCI		FVPL		Level 1		Level 2		Level 3
Assets
Cash and cash equivalents		584,681		486,498		-		98,183		98,183		-		-
Other investments		872,488		763,697		108,791		-		108,791		-		-
Fixed income (time-deposit, zero coupon bonds, commercial papers)		763,697		763,697		-		-		-		-		-
U.S. Sovereign Bills		97,982		97,982		-		-		-		-		-
Non - U.S. Sovereign Bills		14,586		14,586		-		-		-		-		-
Certificates of deposits		222,132		222,132		-		-		-		-		-
Commercial papers		268,737		268,737		-		-		-		-		-
Other notes		160,260		160,260		-		-		-		-		-
Bonds and other fixed income		108,791		-		108,791		-		108,791		-		-
Non - U.S. government securities		20,219		-		20,219		-		20,219		-		-
Corporates securities		88,572		-		88,572		-		88,572		-
Derivative financial instruments		11,449		-		-		11,449		-		11,449		-
Other Investments Non-current		247,082		-		239,422		7,660		239,422		-		7,660
Bonds and other fixed income		239,422		-		239,422		-		239,422		-		-
Other investments		7,660		-		-		7,660		-		-		7,660
Trade receivables		968,148		968,148		-		-		-		-		-
Receivables C and NC (*)		232,152		90,330		48,659		-				-		48,659
Other receivables		138,989		90,330		48,659		-		-		-		48,659
Other receivables (non-financial)		93,163		-		-		-		-		-		-
Total				2,308,673		396,872		117,292		446,396		11,449		56,319
Liabilities
Borrowings C and NC		619,007		619,007		-		-		-		-		-
Trade payables		462,105		462,105		-		-		-		-		-
Finance Lease Liabilities C and NC		257,343		257,343		-		-		-		-		-
Derivative financial instruments		3,217		-		-		3,217		-		3,217		-
Total				1,338,455		-		3,217		-		3,217		-

(*) Includes balances related to interest in our Venezuelan companies. See note 38.

(all amounts in thousands of U.S. dollars)

	Carrying amount		Measurement Categories						At Fair Value
December 31, 2019	Carrying amount		Amortized Cost		FVOCI		FVPL		Level 1		Level 2		Level 3
Assets
Cash and cash equivalents		1,554,299		387,602		-		1,166,697		1,166,697		-		-
Other investments		210,376		65,874		144,502		-		134,990		9,512		-
Fixed income (time-deposit, zero coupon bonds, commercial papers)		65,874		65,874		-		-		-		-		-
Certificates of deposits		20,637		20,637		-		-		-		-		-
Commercial papers		4,993		4,993		-		-		-		-		-
Other notes		40,244		40,244		-		-		-		-		-
Bonds and other fixed income		144,502		-		144,502		-		134,990		9,512		-
U.S. government securities		10,211		-		10,211		-		10,211		-		-
Non - U.S. government securities		28,637		-		28,637		-		19,125		9,512		-
Corporates securities		105,654		-		105,654		-		105,654		-		-
Derivative financial instruments		19,929		-		-		19,929		-		19,929		-
Other Investments Non-current		24,934		-		18,012		6,922		18,012		-		6,922
Bonds and other fixed income		18,012		-		18,012		-		18,012		-		-
Other investments		6,922		-		-		6,922		-		-		6,922
Trade receivables		1,348,160		1,348,160		-		-		-		-		-
Receivables C and NC (*)		261,678		93,239		48,659		-		-		-		48,659
Other receivables		141,898		93,239		48,659		-		-		-		48,659
Other receivables (non-financial)		119,780		-		-		-		-		-		-
Total				1,894,875		211,173		1,193,548		1,319,699		29,441		55,581
Liabilities
Borrowings C and NC		822,152		822,152		-		-		-		-		-
Trade payables		555,887		555,887		-		-		-		-		-
Finance Lease Liabilities C and NC		230,167		230,167		-		-		-		-		-
Derivative financial instruments		1,814		-		-		1,814		-		1,814		-
Total				1,608,206		-		1,814		-		1,814		-

(*) Includes balances related to interest in our Venezuelan companies. See note 38.

There were no transfers between levels during the year.

The fair value of financial instruments traded in active markets is based on quoted market prices at the reporting date. A market is regarded as active if quoted prices are readily and regularly available from an exchange, dealer, broker, industry group, pricing service, or regulatory agency, and those prices represent actual and regularly occurring market transactions on an arm’s length basis. The quoted market price used for financial assets held by Tenaris is the current bid price. These instruments are included in Level 1 and comprise primarily corporate and sovereign debt securities.

The fair value of financial instruments that are not traded in an active market (such as certain debt securities, certificates of deposits with original maturity of more than three months, forward and interest rate derivative instruments) is determined by using valuation techniques which maximize the use of observable market data when available and rely as little as possible on entity specific estimates. If all significant inputs required to value an instrument are observable, the instrument is included in Level 2. Tenaris values its assets and liabilities included in this level using bid prices, interest rate curves, broker quotations, current exchange rates, forward rates and implied volatilities obtained from market contributors as of the valuation date.

If one or more of the significant inputs are not based on observable market data, the instruments are included in Level 3. Tenaris values its assets and liabilities in this level using observable market inputs and management assumptions which reflect the Company’s best estimate on how market participants would price the asset or liability at measurement date. Main balances included in this level correspond to the Company interest in Venezuelan companies. See note 38.

The following table presents the changes in Level 3 assets:

	Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
At the beginning of the year		55,581			52,985
(Decrease) / Addition		(3,604	)		2,933
Increase due to business combinations		3,915			-
Currency translation adjustment and others		427			(337	)
At the end of the year		56,319			55,581

C. Fair value estimation

Financial assets or liabilities classified at fair value through profit or loss are measured under the framework established by the IASB accounting guidance for fair value measurements and disclosures.

The fair values of quoted investments are generally based on current bid prices. If the market for a financial asset is not active or no market is available, fair values are established using standard valuation techniques.

The fair value of all outstanding derivatives is determined using specific pricing models that include inputs that are observable in the market or can be derived from or corroborated by observable data. The fair value of forward foreign exchange contracts is calculated as the net present value of the estimated future cash flows in each currency, based on observable yield curves, converted into U.S. dollars at the spot rate of the valuation date.

Borrowings are classified under other financial liabilities and measured at their amortized cost. Tenaris estimates that the fair value of its main financial liabilities is approximately 100.0% of its carrying amount (including interests accrued) in 2020 and 2019. Fair values were calculated using standard valuation techniques for floating rate instruments and comparable market rates for discounting flows.

The carrying amount of investments valuated at amortized cost approximates its fair value.

D. Accounting for derivative financial instruments and hedging activities

Derivative financial instruments are initially recognized in the statement of financial position at fair value through profit and loss on each date a derivative contract is entered into and are subsequently remeasured at fair value. Specific tools are used for calculation of each instrument’s fair value and these tools are tested for consistency on a monthly basis. Market rates are used for all pricing operations. These include exchange rates, deposit rates and other discount rates matching the nature of each underlying risk.

As a general rule, Tenaris recognizes the full amount related to the change in fair value of derivative financial instruments in Financial Results in the Consolidated Income Statement.

Tenaris designates certain derivatives and non derivative financial liabilities (leasing liabilities denominated in Japanese Yen) as hedges of particular risks associated with recognized assets or liabilities or highly probable forecast transactions. These transactions are classified as cash flow hedges. The effective portion of the fair value of derivatives that are designated and qualify as cash flow hedges is recognized in equity. Similarly the effective portion of the foreign exchange result on the designated leasing liability is recognized in equity. Amounts accumulated in equity are then recognized in the income statement in the same period as the offsetting losses and gains on the hedged item. The gain or loss relating to the ineffective portion is recognized immediately in the income statement. The fair value of Tenaris’s derivative financial instruments (assets or liabilities) continues to be reflected in the statement of financial position. The lease liability will be recognized on the balance sheet at each period end at the exchange rate as of the end of each month. The full fair value of a hedging derivative and the leasing liability is classified as a current or non-current asset or liability according to its expiry date.

For transactions designated and qualifying for hedge accounting, Tenaris documents at the inception of the transaction the relationship between hedging instruments and hedged items, as well as its risk management objectives and strategy for undertaking various hedge transactions. Tenaris also documents its assessment on an ongoing basis, of whether the hedging instrument are highly effective in offsetting changes in the fair value or cash flow of hedged items. At December 31, 2020 and 2019, the effective portion of designated cash flow hedges which is included in Other Reserves in equity amounted to $4.8 million debit and $2.6 million credit respectively. See note 25.

The fair values of various derivative instruments used for hedging purposes and the movements of the hedging reserve included within Other Reserves in equity are disclosed in note 25.

Note 1 - Segment Information

12 Months Ended

Dec. 31, 2020

Disclosure of operating segments [abstract]

Note 1 - Segment Information

1 Segment information

As mentioned in section II.C, the Segment Information is disclosed as follows:

Reportable operating segments

(All amounts in millions of U.S. dollars)

Year ended December 31, 2020	Tubes			Other			Total
IFRS - Net Sales		4,844			303			5,147
Management view - operating (loss)		(277	)		(50	)		(327	)
Differences in cost of sales		(138	)		4			(134	)
Differences in depreciation and amortization		1			(1	)		-
Differences in selling, general and administrative expenses		(2	)		-			(2	)
Differences in other operating income (expenses), net		(200	)		-			(200	)
IFRS - operating (loss)		(616	)		(47	)		(663	)
Financial income (expense), net								(65	)
(Loss) before equity in earnings of non-consolidated companies and income tax								(728	)
Equity in earnings of non-consolidated companies								109
(Loss) before income tax								(619	)
Capital expenditures		189			4			193
Depreciation and amortization		661			18			679

Year ended December 31, 2019	Tubes			Other		Total
IFRS - Net Sales		6,870			424		7,294
Management view - operating income		857			73		930
Differences in cost of sales		(105	)		3		(102)
Differences in depreciation and amortization		(1	)		-		(1	)
Differences in selling, general and administrative expenses		(1	)		1		-
Differences in other operating income (expenses), net		6			-		6
IFRS - operating income		756			77		833
Financial income (expense), net							19
Income before equity in earnings of non-consolidated companies and income tax							852
Equity in earnings of non-consolidated companies							82
Income before income tax							934
Capital expenditures		338			12		350
Depreciation and amortization		523			17		540

Year ended December 31, 2018	Tubes			Other		Total
IFRS - Net Sales		7,233			426		7,659
Management view - operating income		702			81		783
Differences in cost of sales		112			7		119
Differences in depreciation and amortization		(34	)		-		(34	)
Differences in selling, general and administrative expenses		(2	)		6		4
IFRS - operating income		778			94		872
Financial income (expense), net							37
Income before equity in earnings of non-consolidated companies and income tax							909
Equity in earnings of non-consolidated companies							194
Income before income tax							1,103
Capital expenditures		346			3		349
Depreciation and amortization		645			19		664

Transactions between segments, which were eliminated in consolidation, are mainly related to sales of scrap, energy, surplus raw materials and others from the Other segment to the Tubes segment for $16.9, $36.2 and $52.4 million in 2020, 2019 and 2018, respectively.

There are no material differences between IFRS and management view in total revenues and by reportable segments.

The main differences between operating income under IFRS view and the management view are mainly related to the cost of goods sold and other timing differences. See Section II.C - Segment Information. The main difference in Other operating income (expenses), net is attributable to the impairment of the goodwill, which residual value in the management view differs from IFRS.

In addition to the amounts reconciled above, the main differences in net income arise from the impact of functional currencies on financial result, deferred income taxes as well as the result of investment in non-consolidated companies.

Geographical information

(all amounts in thousands of U.S. dollars)	North America	South America	Europe	Middle East & Africa	Asia Pacific	Unallocated (*)	Total
Year ended December 31, 2020
Net sales	2,179,949	776,235	642,793	1,227,532	320,225	-	5,146,734
Total assets	8,071,574	1,868,458	1,461,738	804,559	552,508	957,352	13,716,189
Trade receivables	411,692	115,972	139,427	210,194	90,863	-	968,148
Property, plant and equipment, net	3,971,101	1,050,619	823,057	242,939	105,465	-	6,193,181
Capital expenditures	71,531	63,111	39,691	10,452	8,537	-	193,322
Depreciation and amortization	408,546	106,827	84,518	44,259	34,656	-	678,806

Year ended December 31, 2019
Net sales	3,429,911	1,391,288	738,880	1,382,172	351,804	-	7,294,055
Total assets	7,885,120	2,227,044	2,282,775	958,424	609,663	879,965	14,842,991
Trade receivables	612,809	176,173	149,321	319,406	90,451	-	1,348,160
Property, plant and equipment, net	3,771,570	1,129,260	816,721	254,858	117,608	-	6,090,017
Capital expenditures	169,390	113,999	55,169	4,578	7,038	-	350,174
Depreciation and amortization	276,046	105,308	82,400	42,520	33,247	-	539,521

Year ended December 31, 2018
Net sales	3,611,509	1,462,044	724,733	1,559,988	300,314	-	7,658,588
Total assets	7,971,311	2,489,522	1,913,589	588,746	482,563	805,568	14,251,299
Trade receivables	791,190	280,801	215,202	383,358	66,815	-	1,737,366
Property, plant and equipment, net	3,859,060	1,133,113	848,178	94,040	129,517	-	6,063,908
Capital expenditures	196,220	68,603	77,467	2,047	5,136	-	349,473
Depreciation and amortization	441,705	108,558	82,769	10,389	20,936	-	664,357

(*) For 2020, 2019 and 2018 includes Investments in non-consolidated companies. See note 13.

There are no revenues from external customers attributable to the Company’s country of incorporation (Luxembourg).

The principal countries from which the Company derives its revenues are USA (26%), Mexico, Argentina, Canada, Saudi Arabia, Brazil and Italy.

Revenue is mainly recognized at a point in time to direct customers, when control has been transferred and there is no unfulfilled performance obligation that could affect the acceptance of the product by the customer. Revenues related to governmental institutions represents approximately 24%, 21% and 15% in 2020, 2019 and 2018 respectively.

Tubes segment revenues by market:

Revenues Tubes (in millions of U.S. dollars)	2020	2019	2018
Oil and Gas	4,073	5,757	6,042
Hydrocarbon Processing and Power Generation	371	534	602
Industrial and Other	400	579	589
Total	4,844	6,870	7,233

At December 31, 2020, 2019 and 2018, the Company recognized contract liabilities related to customer advances in the amount of $48.7, $82.7 and $62.7 million, respectively. These amounts related to years 2019 and 2018 were reclassified to revenues during the subsequent year. In these periods, no significant adjustment in revenues were performed related to performance obligations previously satisfied.

Note 2 - Cost of Sales

12 Months Ended

Dec. 31, 2020

Disclosure of Cost of Sales [Abstract]

Note 2 - Cost of Sales

2 Cost of sales

	Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019			2018

Inventories at the beginning of the year		2,265,880			2,524,341			2,368,304
Increase in inventory due to business combinations		199,589			52,966			-
Plus: Charges of the year
Raw materials, energy, consumables and other		1,545,688			2,709,629			3,400,396
Services and fees		154,976			222,415			275,130
Labor cost (*)		757,359			870,261			855,040
Depreciation of property, plant and equipment		503,725			428,791			432,497
Amortization of intangible assets		8,121			5,948			8,220
Depreciation of right-of-use assets		40,127			28,727			-
Maintenance expenses		107,764			284,758			185,782
Allowance for obsolescence		35,809			29,138			25,457
Taxes		45,162			100,738			133,308
Other		59,790			115,663			119,507
		3,458,110			4,849,034			5,435,337
Less: Inventories at the end of the year		(1,636,673	)		(2,265,880	)		(2,524,341	)
		4,087,317			5,107,495			5,279,300

(*) For the year ended December 2020, 2019 and 2018, labor cost includes approximately $81.3 million, $17.2 million and $15.0 million respectively of severance indemnities related to the adjustment of the workforce to market conditions.

Note 3 - Selling, General and Administrative Expenses

12 Months Ended

Dec. 31, 2020

Selling, general and administrative expense [abstract]

Note 3 - Selling, General and Administrative Expenses

3 Selling, general and administrative expenses

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020		2019		2018

Services and fees		115,883		153,773		128,090
Labor cost (*)		444,436		481,854		470,928
Depreciation of property, plant and equipment		26,814		18,524		16,968
Amortization of intangible assets		82,355		41,967		206,672
Depreciation of right-of-use assets		17,664		15,564		-
Commissions, freight and other selling expenses		310,815		441,442		491,555
Provisions for contingencies		11,957		28,565		23,498
Allowances for doubtful accounts		4,644		(16,256)		1,751
Taxes		63,234		110,876		71,110
Other		41,425		89,665		99,404
		1,119,227		1,365,974		1,509,976

(*) For the year ended December 2020, 2019 and 2018, labor cost includes approximately $61.2 million, $7.4 million and $10.2 million respectively of severance indemnities related to the adjustment of the workforce to market conditions.

Note 4 - Labor Costs - Labor Costs (Included in Cost of Sales and in Selling, General and Administrative Expenses)

12 Months Ended

Dec. 31, 2020

4. Labor costs (included in Cost of sales and in Selling, general and administrative expenses)

4. Labor costs (included in Cost of sales and in Selling, general and administrative expenses)

4 Labor costs (included in Cost of sales and in Selling, general and administrative expenses)

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019		2018

Wages, salaries and social security costs		1,036,211			1,274,474		1,250,783
Severance indemnities		142,458			24,637		25,225
Defined contribution plans		12,442			12,663		13,217
Pension benefits - defined benefit plans		11,097			18,207		15,390
Employee retention and long term incentive program		(413	)		22,134		21,353
		1,201,795			1,352,115		1,325,968

The following table shows the geographical distribution of the employees:

Country	2020		2019		2018
Mexico		4,501		5,370		5,595
Argentina		4,376		5,405		5,427
Italy		2,039		2,144		2,155
USA		1,596		2,255		2,382
Romania		1,552		1,815		1,852
Brazil		1,360		1,360		1,287
Colombia		746		1,040		1,082
Canada		561		772		1,030
Indonesia		521		616		554
Japan		399		400		399
Other		1,377		2,023		1,204
		19,028		23,200		22,967

Note 5 - Impairment charge

12 Months Ended

Dec. 31, 2020

Disclosure of impairment loss and reversal of impairment loss [abstract]

Note 5 - Impairment charge

5 Impairment charge

Tenaris’s main source of revenue is the sale of products and services to the oil and gas industry, and the level of such sales is sensitive to international oil and gas prices and their impact on drilling activities.

A decline during the first months of 2020 in oil prices and futures resulted in reductions in Tenaris customers` investments. Drilling activity and demand of products and services, particularly in North America, also declined. Selling prices of products in North America were also affected by low levels of consumption caused by the spread of COVID-19 pandemic. For more information on these effects, refer to note 39.

The Company conducts regular assessments of the carrying values of its assets. The value-in-use was used to determine the recoverable value. Value-in-use is calculated by discounting the estimated cash flows over a five year period (or higher if the period can be justified) based on forecasts approved by management. For the subsequent years beyond the five-year period, a terminal value is calculated based on perpetuity considering a nominal growth rate of 2% taking into account among others, mainly the historical inflation rate.

The main key assumptions used in estimating the value in use are discount rate, growth rate and competitive and economic factors applied to determine cash flow projections, such as oil and gas prices, average number of active oil and gas drilling rigs (rig count) and raw material costs.

For purposes of assessing key assumptions, to estimate discounted future cash flows, the Company uses external sources of information and management judgment based on past experience. Management has determined the value of each of the key assumptions as follows:

- Discount rate: based on the applicable weighted average cost of capital (“WACC”), which is considered to be a good indicator of capital cost, taking into account the industry, country and size of the business. For each CGU where assets are allocated, a specific WACC was determined taking into account the industry, country and size of the business. In 2020, the main discount rates used were in a range between 8.0% and 13.6%.

- Growth rate: considers mainly the inflation impact on prices and costs, the long-term average growth rate for the oil and gas industry, the higher demand to offset depletion of existing fields and the Company’s expected market penetration. In 2020, a nominal growth rate of 2% was considered.

- Oil and gas prices: based on industry analysts’ reports and management’s expectations of market development respectively.

- Rig count: based on information published by Baker Hughes and management’s expectations.

- Raw material costs: based on industry analysts’ reports and management’s expectations.

In March, 2020, as a result of the deterioration of business conditions and in light of the presence of impairment indicators for its assets in the United States, the Company decided to write down the goodwill and other long lived assets recording an impairment charge of approximately $622 million, impacting the carrying value of goodwill of the CGUs OCTG-USA, IPSCO and Coiled Tubing for $225 million, $357 million and $4 million respectively, and the carrying value of fixed assets of the CGU Rods-USA for $36 million. Out of the total amount, $582 million were allocated to the Tubes segment. No impairment charges were recorded for the years 2019 and 2018.

(all amounts in millions of U.S. dollars)	Assets before impairment	Impairment	Assets after impairment
OCTG - USA	544	225	319
IPSCO	1,169	357	812
Coiled Tubing	108	4	104
Rods - USA	73	36	37

The main factors that could result in additional impairment charges in future periods would be an increase in the discount rate or a decrease in growth rate used in the Company’s cash flow projections, a deterioration of the business, competitive and economic factors, such as a decrease in oil and gas prices, and the evolution of the rig count.

An increase of 100 Bps in the discount rate, a decline of 100 Bps in the growth rate or a decline of 5% in the cash flow projections, would have generated an additional impairment as showed in the below table.

(all amounts in millions of U.S. dollars)	+100Bps Discount rate	-100Bps Growth rate	-5% Cash flows
OCTG - USA	(60)	(43)	(16)
IPSCO	(117)	(77)	(41)
Coiled Tubing	(12)	(6)	(5)
Rods - USA	(5)	(3)	(2)

Note 6 - Other operating income and expenses

12 Months Ended

Dec. 31, 2020

Note 5 - Other Operating Income and Expenses

Note 6 - Other Operating Income and Expenses

6 Other operating income and expenses

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020		2019		2018

Other operating income
Net income from other sales		9,891		8,651		3,604
Net rents		5,501		5,089		4,909
Other		18,001		8,025		6,546
Recovery on allowance for doubtful receivables		-		1,239		-
		33,393		23,004		15,059

Other operating expenses
Contributions to welfare projects and non-profit organizations		12,989		11,199		11,379
Allowance for doubtful receivables		1,263		-		1,179
		14,252		11,199		12,558

Note 7 - Financial Results

12 Months Ended

Dec. 31, 2020

Disclosure of Financial Results [Abstract]

Note 7 - Financial Results

7 Financial results

(all amounts in thousands of U.S. dollars)	Year ended December 31,
	2020			2019			2018

Interest Income		21,625			48,061			42,244
Net result on changes in FV of financial assets at FVPL		-			(64	)		(2,388	)
Impairment result on financial assets at FVTOCI		(3,238	)		-			-
Finance income (*)		18,387			47,997			39,856
Finance cost		(27,014	)		(43,381	)		(36,942	)
Net foreign exchange transactions results (**)		(74,422	)		27,868			28,845
Foreign exchange derivatives contracts results (***)		19,644			(11,616	)		6,576
Other		(1,590	)		(1,585	)		(1,035	)
Other financial results		(56,368	)		14,667			34,386
Net financial results		(64,995	)		19,283			37,300

(*) Finance Income:

In 2020, 2019 and 2018 includes $6.5, $7.6 and $3.6 million of interest related to instruments carried at FVPL, respectively.

(**) Net foreign exchange transactions results:

In 2020 mainly includes the negative impact from Euro appreciation against the U.S. dollar on Euro denominated intercompany liabilities in subsidiaries with functional currency U.S. dollar, largely offset by the currency translation adjustment reserve from our Italian subsidiary, together with the negative impact from Brazilian Real depreciation against the U.S. dollar on U.S. dollar denominated intercompany liabilities in subsidiaries with functional currency Brazilian Real, largely offset by the currency translation adjustment reserve from our Brazilian subsidiaries. Also includes the negative result from the Mexican peso depreciation against the U.S. dollar on peso denominated trade, social, fiscal and financial positions at Mexican subsidiaries with functional currency U.S. dollar.

In 2019 mainly includes the result from the Argentine peso depreciation against the U.S. dollar on peso denominated financial, trade, social and fiscal payables and receivables at Argentine subsidiaries with functional currency U.S. dollar.

In 2018 mainly includes the result from the Argentine peso depreciation against the U.S. dollar on peso denominated financial, trade, social and fiscal payables and receivables at Argentine subsidiaries with functional currency U.S. dollar, together with the positive impact from Euro depreciation against the U.S. dollar on Euro denominated intercompany liabilities in subsidiaries with functional currency U.S. dollar, largely offset by the currency translation adjustment reserve from our Italian subsidiary.

(***) Foreign exchange derivatives contracts results:

In 2020 includes mainly gain on derivatives covering net receivables in Mexican peso, Brazilian real and Canadian dollar and net payables in Euro.

In 2019 includes mainly losses on derivatives covering net payables in Argentine peso and Euro and net receivables in Canadian dollar.

In 2018 includes mainly gain on derivatives covering net receivables in Canadian dollar.

Note 8 - Income Tax

12 Months Ended

Dec. 31, 2020

Major components of tax expense (income) [abstract]

Note 8 - Income Tax

8 Income tax

	Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019			2018

Current tax		(121,048	)		(299,692	)		(343,104	)
Deferred tax		97,898			97,240			113,897
Tax charge		(23,150	)		(202,452	)		(229,207	)

The tax on Tenaris’s income before tax differs from the theoretical amount that would arise using the tax rate in each country as follows:

	Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019			2018

(Loss) Income before income tax		(619,267	)		933,710			1,103,107
Less Impairment charges (non deductible)		622,402			-			-
Income before income tax without impairment charges		3,135			933,710			1,103,107


Tax calculated at the tax rate in each country		21,052			(186,752	)		(207,422	)
Effect of currency translation on tax base		(72,936	)		(53,296	)		(77,552	)
Changes in the tax rates		(958	)		13			(1,824	)
Utilization of previously unrecognized tax losses		98			547			-
Tax revaluation, withholding tax and others		29,594			37,036			57,591
Tax charges		(23,150	)		(202,452	)		(229,207	)

Effect of currency translation on tax base, Tenaris applies the liability method to recognize deferred income tax on temporary differences between the tax bases of assets / liabilities and their carrying amounts in the financial statements. By application of this method, Tenaris recognizes gains and losses on deferred income tax due to the effect of the change in the value on the tax bases in subsidiaries (mainly Argentina and Mexico), which have a functional currency different than their local currency. These gains and losses are required by IFRS even though the revalued / devalued tax bases of the relevant assets will not result in any deduction / obligation for tax purposes in future periods.

Tax revaluation, withholding tax and others, includes a net tax income of $61 million, $66 million and $65 million for 2020, 2019 and 2018 respectively related to the tax revaluation regimes in Argentina and Mexico. It also includes a charge of $10 million, $34 million and $26 million for 2020, 2019 and 2018 respectively related to withholding taxes for intra-group international operations.

Note 9 - Dividends Distribution	12 Months Ended
Note 9 - Dividends Distribution	Dec. 31, 2020
Disclosure of Dividends Distribution [Abstract]
Note 9 - Dividends Distribution	9 Dividends distribution On November 4, 2020, the Company’s Board of Directors approved the payment of an interim dividend of $0.07 per share ($0.14 per ADS), or approximately $82.6 million, payable on November 25, 2020, with an ex-dividend date of November 23, 2020. On June 2, 2020, the Company’s Shareholders approved that, as a consequence of liquidity preservation initiatives, no further dividends be distributed in respect of fiscal year 2019 beyond the interim dividend of approximately $153 million already paid in November 2019. On May 6, 2019, the Company’s Shareholders approved an annual dividend in the amount of $0.41 per share ($0.82 per ADS). The amount approved included the interim dividend previously paid on November 21, 2018 in the amount of $0.13 per share ($0.26 per ADS). The balance, amounting to $0.28 per share ($0.56 per ADS), was paid on May 22, 2019. In the aggregate, the interim dividend paid in November 2018 and the balance paid in May 2019 amounted to approximately $484 million. On May 2, 2018, the Company’s Shareholders approved an annual dividend in the amount of $0.41 per share ($0.82 per ADS). The amount approved included the interim dividend previously paid on November 22, 2017 in the amount of $0.13 per share ($0.26 per ADS). The balance, amounting to $0.28 per share ($0.56 per ADS), was paid on May 23, 2018. In the aggregate, the interim dividend paid in November 2017 and the balance paid in May 2018 amounted to approximately $484 million.

Note 10 - Property, Plant and Equipment, Net

12 Months Ended

Dec. 31, 2020

Disclosure of detailed information about property, plant and equipment [abstract]

Note 10 - Property, Plant and Equipment, Net

10 Property, plant and equipment, net

(all amounts in thousands of U.S. dollars)

Year ended December 31, 2020	Land and civil buildings		Industrial buildings, plant and production equipment		Vehicles, furniture and fixtures		Work in progress		Spare parts and equipment		Total

Cost
Values at the beginning of the year		799,139		12,468,813		399,724		108,308		60,602		13,836,586
Currency translation adjustment		(545)		72,650		443		(2,095)		(162)		70,291
Increase due to business combinations (*)		39,622		440,366		7,195		16,255		-		503,438
Additions		1,451		1,524		620		157,315		6,845		167,755
Transfers / Reclassifications		5,881		157,473		15,586		(176,589)		-		2,351
Disposals / Consumptions		(5,964)		(61,281)		(8,811)		(968)		(5,392)		(82,416)
Values at the end of the year		839,584		13,079,545		414,757		102,226		61,893		14,498,005

Depreciation and impairment
Accumulated at the beginning of the year		121,468		7,302,135		322,966		-		-		7,746,569
Currency translation adjustment		(288)		56,560		405		-		-		56,677
Depreciation charge		11,368		492,973		26,198		-		-		530,539
Impairment charge (See note 5)		-		36,000		-		-		-		36,000
Transfers / Reclassifications		(1)		349		(475)		-		-		(127)
Disposals / Consumptions		(89)		(57,897)		(6,848)		-		-		(64,834)
Accumulated at the end of the year		132,458		7,830,120		342,246		-		-		8,304,824
At December 31, 2020		707,126		5,249,425		72,511		102,226		61,893		6,193,181

(all amounts in thousands of U.S. dollars)

Year ended December 31, 2019	Land and civil buildings		Industrial buildings, plant and production equipment		Vehicles, furniture and fixtures		Work in progress		Spare parts and equipment		Total

Cost
Values at the beginning of the year		732,578		12,121,569		377,260		127,378		63,197		13,421,982
Currency translation adjustment		(1,611)		(38,961)		(1,615)		(864)		(256)		(43,307)
Increase due to business combinations (**)		59,468		115,908		1,733		1,630		-		178,739
Additions		16		1,178		1,107		299,412		12,202		313,915
Transfers / Reclassifications		8,723		296,272		28,349		(317,128)		(11,984)		4,232
Disposals / Consumptions		(35)		(27,153)		(7,110)		(2,120)		(2,557)		(38,975)
Values at the end of the year		799,139		12,468,813		399,724		108,308		60,602		13,836,586

Depreciation and impairment
Accumulated at the beginning of the year		110,914		6,936,900		310,260		-		-		7,358,074
Currency translation adjustment		(420)		(24,973)		(1,485)		-		-		(26,878)
Depreciation charge		11,409		415,826		20,080		-		-		447,315
Transfers / Reclassifications		(362)		(38)		-		-		-		(400)
Disposals / Consumptions		(73)		(25,580)		(5,889)		-		-		(31,542)
Accumulated at the end of the year		121,468		7,302,135		322,966		-		-		7,746,569
At December 31, 2019		677,671		5,166,678		76,758		108,308		60,602		6,090,017

(*) Related to IPSCO acquisition. See note 32.

(**) Related to SSPC acquisition. See note 32.

Property, plant and equipment include capitalized interests for net amounts at December 31, 2020 and 2019 of $33.6 million and $35.4 million, respectively. There were no interest capitalized during 2020 and 2019.

The carrying amounts of assets pledged as security for current and non-current borrowings are immaterial for the years 2020 and 2019.

Note 11 - Intangible Assets, Net

12 Months Ended

Dec. 31, 2020

Disclosure of detailed information about intangible assets [abstract]

Note 11 - Intangible Assets, Net

11 Intangible assets, net

(all amounts in thousands of U.S. dollars)

Year ended December 31, 2020	Information system projects			Licenses, patents and trademarks (*)			Goodwill			Customer relationships		Total

Cost
Values at the beginning of the year		604,870			463,742			2,117,837			2,140,051		5,326,500
Currency translation adjustment		1,108			220			(5,058	)		-		(3,730	)
Increase due to business combinations (**)		11,563			87,000			357,183			71,100		526,846
Additions		24,965			602			-			-		25,567
Transfers / Reclassifications		(1,393	)		-			-			-		(1,393	)
Disposals		(3,761	)		(1,064	)		-			-		(4,825	)
Values at the end of the year		637,352			550,500			2,469,962			2,211,151		5,868,965

Amortization and impairment
Accumulated at the beginning of the year		536,337			373,772			797,592			2,057,240		3,764,941
Currency translation adjustment		890			(1	)		-			-		889
Amortization charge		42,931			8,760			-			38,785		90,476
Impairment charge (See note 5)		-			-			586,402			-		586,402
Transfers / Reclassifications		931			-			-			-		931
Disposals		(3,730	)		-			-			-		(3,730	)
Accumulated at the end of the year		577,359			382,531			1,383,994			2,096,025		4,439,909
At December 31, 2020		59,993			167,969			1,085,968			115,126		1,429,056

(all amounts in thousands of U.S. dollars)

Year ended December 31, 2019	Information system projects			Licenses, patents and trademarks (*)			Goodwill			Customer relationships		Total
Cost
Values at the beginning of the year		580,622			464,571			2,085,936			2,058,859		5,189,988
Currency translation adjustment		(1,917	)		(70	)		(968	)		-		(2,955	)
Increase due to business combinations (***)		405			-			32,869			81,192		114,466
Additions		35,487			772			-			-		36,259
Transfers / Reclassifications		(4,665	)		-			-			-		(4,665	)
Disposals		(5,062	)		(1,531	)		-			-		(6,593	)
Values at the end of the year		604,870			463,742			2,117,837			2,140,051		5,326,500

Amortization and impairment
Accumulated at the beginning of the year		513,984			373,466			797,592			2,038,981		3,724,023
Currency translation adjustment		(1,734	)		-			-			-		(1,734	)
Amortization charge		28,937			719			-			18,259		47,915
Disposals		(4,850	)		(413	)		-			-		(5,263	)
Accumulated at the end of the year		536,337			373,772			797,592			2,057,240		3,764,941
At December 31, 2019		68,533			89,970			1,320,245			82,811		1,561,559

(*) Includes Proprietary Technology.

(**) Related to IPSCO acquisition. See note 32.

(***) Related to SSPC acquisition. See note 32.

The geographical allocation of goodwill for the year ended December 31, 2020 was $939.2 million for North America, $111.1 million for South America, $33.7 million for Middle East & Africa and $2.0 million for Europe.

The carrying amount of goodwill allocated by CGU, as of December 31, 2020, was as follows:

(all amounts in millions of U.S. dollars)
	Tubes Segment
CGU	Hydril Acquisition		Other		Total
Tamsa (Hydril and other)		346		19		365
Siderca (Hydril and other)		265		93		358
Hydril		309		-		309
Other		-		54		54
Total		920		166		1,086

Note 12 - Right-of-use Assets, Net and Lease Liabilities

12 Months Ended

Dec. 31, 2020

Presentation of leases for lessee [abstract]

Note 12 - Right-of-use Assets, Net and Lease Liabilities

12 Right-of-use assets, net and lease liabilities

Right of use assets evolution

(all amounts in thousands of U.S. dollars)

Year ended December 31, 2020	Land and Civil Buildings			Industrial Buildings, Plant and Production Equipment			Vehicles, furniture and fixtures			Total
Cost
Opening net book amount		36,137			225,389			14,194			275,720
Currency translation adjustment		(839	)		746			530			437
Increase due to business combinations (*)		3,461			13,730			7,556			24,747
Additions		11,534			42,573			5,034			59,141
Transfers / Reclassifications		439			(458	)		136			117
Disposals		(8,800	)		(8,622	)		(8,835	)		(26,257	)
At December 31, 2020		41,932			273,358			18,615			333,905


Depreciation
Accumulated at the beginning of the year		8,330			30,581			3,683			42,594
Currency translation adjustment		(92	)		145			190			243
Depreciation charge		13,200			37,671			6,920			57,791
Transfers / Reclassifications		(2,876	)		1,702			1,291			117
Disposals		(3,420	)		(2,106	)		(3,267	)		(8,793	)
Accumulated at the end of the year		15,142			67,993			8,817			91,952
At December 31, 2020		26,790			205,365			9,798			241,953

(all amounts in thousands of U.S. dollars)

Year ended December 31, 2019	Land and Civil Buildings			Industrial Buildings, Plant and Production Equipment			Vehicles, furniture and fixtures			Total
Cost
Opening net book amount		27,713			202,352			8,335			238,400
Currency translation adjustment		(88	)		6			8			(74	)
Increase due to business combinations (**)		229			2,038			-			2,267
Additions		9,292			24,985			7,165			41,442
Transfers / Reclassifications		-			496			(496	)		-
Disposals		(1,009	)		(4,488	)		(818	)		(6,315	)
At December 31, 2019		36,137			225,389			14,194			275,720


Depreciation
Accumulated at the beginning of the year		-			-			-			-
Currency translation adjustment		(3	)		3			8			8
Depreciation charge		8,514			31,869			3,908			44,291
Transfers / Reclassifications		-			(62	)		62			-
Disposals		(181	)		(1,229	)		(295	)		(1,705	)
Accumulated at the end of the year		8,330			30,581			3,683			42,594
At December 31, 2019		27,807			194,808			10,511			233,126

(*) Related to IPSCO acquisition. See note 32.

(**) Related to SSPC acquisition.

Depreciation of right-of-use assets is mainly included in Tubes segment.

The initial cost of right-of-use assets consists of the initial lease liability plus lease payments made in 2018 of approximately $4 million.

Lease liability evolution

	Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019

Opening net book amount		230,167			234,149
Increase due to business combinations		26,046			2,267
Translation differences		7,656			2,690
Additions		58,536			36,957
Cancellations		(17,529	)		(4,688	)
Repayments (*)		(51,666	)		(43,974	)
Interest accrued		4,133			2,766
At December 31,		257,343			230,167

(*) Repayments include capital and interest.

The amount of remaining payments with maturity less than 1 year, between 2 and 5 years and more than 5 years is approximately 16.9%, 40.5% and 42.6% of the total remaining payments, respectively.

Expenses related to short-term leases and low value leases (included in cost of sales and selling, general and administrative expenses) for the year 2020 amounted to $1.7 million and $3.2 million respectively and for the year 2019 amounted to $15.1 million and $1.3 million respectively. Expenses related to variable leases (included in cost of sales and selling, general and administrative expenses) were not material for the years 2020 and 2019.

Note 13 - Investments in Non-consolidated Companies

12 Months Ended

Dec. 31, 2020

Disclosure of unconsolidated structured entities [abstract]

Note 13 - Investments in Non-consolidated Companies

13 Investments in non-consolidated companies

	Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
At the beginning of the year		879,965			805,568
Translation differences		(31,977	)		(10,781	)
Equity in earnings of non-consolidated companies		108,799			82,036
Increase due to business combinations		-			20,635
Dividends and distributions declared (*)		(861	)		(28,037	)
Additions		-			19,610
Increase / (decrease) in equity reserves and others		1,426			(9,066	)
At the end of the year		957,352			879,965

(*) Related to Ternium and Usiminas. During 2020 and 2019 $0.3 million and $29.0 million respectively were collected.

The principal non-consolidated companies are:

		% ownership at December 31,		Value at December 31,
Company	Country of incorporation	2020	2019	2020	2019
a) Ternium (*)	Luxembourg	11.46%	11.46%	830,028	751,105
b) Usiminas (**)	Brazil	3.07%	3.07%	65,144	74,593
c) Techgen	Mexico	22.00%	22.00%	19,536	9,888
d) Global Pipe Company	Saudi Arabia	35.00%	35.00%	23,421	22,550
Others	-	-	-	19,223	21,829
				957,352	879,965

(*) Including treasury shares.

(**) At December 31, 2020 and 2019 the voting rights were 5.19%.

a) Ternium

Ternium, is a steel producer with production facilities in Mexico, Argentina, Brazil, Colombia, United States and Guatemala and is one of Tenaris’s main suppliers of round steel bars and flat steel products for its pipes business.

At December 31, 2020, the closing price of Ternium’s ADSs as quoted on the New York Stock Exchange was $29.08 per ADS, giving Tenaris’s ownership stake a market value of approximately $668 million. At December 31, 2020, the carrying value of Tenaris’s ownership stake in Ternium, based on Ternium’s IFRS Financial Statements, was approximately $830 million.

As of December 31, 2020, the Company concluded that the carrying amount does not exceed the recoverable value of the investment.

Summarized selected financial information of Ternium, including the aggregated amounts of assets, liabilities, revenues and profit or loss is as follows:

(all amounts in thousands of U.S. dollars)	Ternium
	2020	2019
Non-current assets	8,289,460	8,757,320
Current assets	4,566,775	4,178,213
Total assets	12,856,235	12,935,533
Non-current liabilities	2,559,485	3,452,535
Current liabilities	1,853,597	1,768,125
Total liabilities	4,413,082	5,220,660

Equity	8,443,153	7,714,873

Revenues	8,735,435	10,192,818
Gross profit	1,635,512	1,740,378
Net income for the year attributable to owners of the parent	778,468	564,269
Total comprehensive income for the year, net of tax, attributable to owners of the parent	666,667	445,473

b) Usiminas

Usiminas is a Brazilian producer of high quality flat steel products used in the energy, automotive and other industries.

As of December 31, 2020, the closing price of the Usiminas’ ordinary and preferred shares, as quoted on the B3 - Brasil Bolsa Balcão S.A, was BRL15.69 ($3.02) and BRL14.61 ($2.81), respectively, giving Tenaris’s ownership stake a market value of approximately $113.8 million. As of that date, the carrying value of Tenaris’s ownership stake in Usiminas was approximately $65.1 million.

Summarized selected financial information of Usiminas, including the aggregated amounts of assets, liabilities, revenues and profit or loss is as follows:

(all amounts in thousands of U.S. dollars)	Usiminas
	2020	2019
Non-current assets	3,487,317	4,335,662
Current assets	2,276,368	2,198,449
Total assets	5,763,685	6,534,111
Non-current liabilities	1,661,605	1,955,395
Current liabilities	861,912	716,930
Total liabilities	2,523,517	2,672,325

Equity	3,240,168	3,861,786

Revenues	3,132,949	3,790,206
Gross profit	624,199	478,141
Net income for the year attributable to owners of the parent	106,361	52,779

c) Techgen

Techgen is a Mexican company that operates a natural gas-fired combined cycle electric power plant in the Pesquería area of the State of Nuevo León, Mexico, and started producing energy on December 1, 2016, with a power capacity of 900 megawatts. As of December 31, 2020, Tenaris held 22% of Techgen’s share capital, and its affiliates, Ternium and Tecpetrol (both controlled by San Faustin), held 48% and 30% respectively. As of December 31, 2020, the carrying value of Tenaris’s ownership stake in Techgen was approximately $19.5 million.

Techgen entered into certain transportation capacity agreements, a contract for the purchase of power generation equipment and other services related to the equipment, and an agreement for the purchase of clean energy certificates. As of December 31, 2020, Tenaris’s exposure under these agreements amounted to $48.8 million, $0.9 million and $17.6 million respectively.

During 2019, Techgen repaid certain subordinated loans to Techgen’s sponsors; the portion corresponding to Tenaris amounted to $40.5 million. As of December 31, 2020, the aggregate outstanding principal amount under these subordinated loans was $58.1 million.

Techgen is a party to a $640 million syndicated loan agreement, which is “non-recourse” on the sponsors. Techgen’s obligations thereunder are guaranteed by a Mexican security trust (covering shares, assets, accounts and contract rights), account pledges and certain direct agreements –customary for these type of transactions–. The commercial terms and conditions governing the purchase of 22% of the energy generated by Techgen, by the Company’s Mexican subsidiary, Tamsa, remain substantially unchanged.

Under the loan agreement, Techgen is committed to maintain a debt service reserve account covering debt service becoming due during two consecutive quarters; such account is funded by stand-by letters of credit issued for the account of Techgen’s sponsors in proportion to their respective participations in Techgen. Accordingly, the Company and its Swiss subsidiary, Tenaris Investments Switzerland AG, applied for stand-by letters of credit covering 22% of the debt service coverage ratio, which as of the date hereof amounts to $9.8 million.

d) GPC

GPC is a Saudi-German joint venture, established in 2010 and located in Jubail, Saudi Arabia, which manufactures LSAW pipes. Tenaris, through its subsidiary SSPC, currently owns 35% of the share capital of GPC. As of December 31, 2020, the carrying value of Tenaris’s ownership stake in GPC was approximately $23.4 million.

SSPC and the other three owners of GPC have issued corporate guarantees to secure repayment of loan agreements entered into by GPC, with the Saudi Investment Development Fund, the Saudi British Bank, the National Commercial Bank and Banque Saudi Fransi to finance GPC’s capital expenditures and working capital. As of December 31, 2020, SSPC’s exposure under the guarantees amounted to $131.5 million.

Note 14 - Receivables - Non Current

12 Months Ended

Dec. 31, 2020

Trade and other non-current receivables [abstract]

Note 14 - Receivables - Non Current

14 Receivables – non current

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020		2019
Employee advances and loans		4,563		6,008
Tax credits		18,046		20,065
Receivables from related parties		62,790		59,999
Legal deposits		8,600		12,378
Advances to suppliers and other advances		4,803		3,772
Receivable Venezuelan subsidiaries		48,659		48,659
Others		6,842		6,222
		154,303		157,103

Note 15 - Inventories, Net

12 Months Ended

Dec. 31, 2020

Classes of current inventories [abstract]

Note 15 - Inventories, Net

15 Inventories, net

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
Finished goods		691,922			968,329
Goods in process		417,097			612,888
Raw materials		143,558			221,954
Supplies		488,802			486,411
Goods in transit		158,929			194,015
		1,900,308			2,483,597
Allowance for obsolescence, see note 24 (i)		(263,635	)		(217,717	)
		1,636,673			2,265,880

Note 16 - Receivables and Prepayments, Net

12 Months Ended

Dec. 31, 2020

Current prepayments and current accrued income [abstract]

Note 16 - Receivables and Prepayments, Net

16 Receivables and prepayments, net

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
Prepaid expenses and other receivables		26,457			30,579
Government entities		3,075			1,867
Employee advances and loans		4,672			8,189
Advances to suppliers and other advances		14,661			17,180
Government tax refunds on exports		2,723			670
Receivables from related parties		16,217			19,837
Miscellaneous		13,961			31,145
		81,766			109,467
Allowance for other doubtful accounts, see note 24 (i)		(3,917	)		(4,892	)
		77,849			104,575

Note 17 - Current Tax Assets and Liabilities

12 Months Ended

Dec. 31, 2020

Disclosure of Current Tax Receivables and Payables [Abstract]

Note 17 - Current Tax Assets and Liabilities

17 Current tax assets and liabilities

(all amounts in thousands of U.S. dollars)

		Year ended December 31,
Current tax assets	2020		2019
V.A.T. credits		106,293		112,161
Prepaid taxes		30,091		55,227
		136,384		167,388

		Year ended December 31,
Current tax liabilities	2020		2019
Income tax liabilities		27,616		64,994
V.A.T. liabilities		9,933		9,953
Other taxes		53,044		52,678
		90,593		127,625

Note 18 - Trade Receivables, Net

12 Months Ended

Dec. 31, 2020

Trade and other receivables [abstract]

Note 18 - Trade Receivables, Net

18 Trade receivables, net

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
Current accounts		1,017,663			1,387,494
Receivables from related parties		4,161			9,448
		1,021,824			1,396,942
Allowance for doubtful accounts, see note 24 (i)		(53,676	)		(48,782	)
		968,148			1,348,160

The following table sets forth details of the aging of trade receivables:

(all amounts in thousands of U.S. dollars)	Trade Receivables			Not Due			Past due
	Trade Receivables			Not Due			1 - 180 days			> 180 days
At December 31, 2020
Guaranteed		191,514			170,796			18,778			1,940
Not guaranteed		830,310			655,132			116,802			58,376
Guaranteed and not guaranteed		1,021,824			825,928			135,580			60,316
Expected loss rate		0.07	%		0.04	%		0.23	%		0.72	%
Allowances for doubtful accounts		(721	)		(321	)		(331	)		(69	)
Nominative allowances for doubtful accounts		(52,955	)		(718	)		(1,011	)		(51,226	)
Net Value		968,148			824,889			134,238			9,021

(all amounts in thousands of U.S. dollars)	Trade Receivables			Not Due			Past due
	Trade Receivables			Not Due			1 - 180 days			> 180 days
At December 31, 2019
Guaranteed		234,427			205,764			26,899			1,764
Not guaranteed		1,162,515			948,449			157,960			56,106
Guaranteed and not guaranteed		1,396,942			1,154,213			184,859			57,870
Expected loss rate		0.09	%		0.04	%		0.24	%		0.57	%
Allowances for doubtful accounts		(1,294	)		(529	)		(455	)		(310	)
Nominative allowances for doubtful accounts		(47,488	)		-			(1,922	)		(45,566	)
Net Value		1,348,160			1,153,684			182,482			11,994

Trade receivables are mainly denominated in U.S. dollars.

Note 19 - Cash and Cash Equivalents and Other Investments

12 Months Ended

Dec. 31, 2020

Disclosure of Cash and Cash Equivalents and Other Investments [Abstract]

Note 19 - Cash and Cash Equivalents and Other Investments

19 Cash and cash equivalents and other investments

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020		2019
Cash and cash equivalents
Cash at banks		117,807		118,314
Liquidity funds		98,183		1,166,697
Short – term investments		368,691		269,288
		584,681		1,554,299
Other investments - current
Fixed income (time-deposit, zero coupon bonds, commercial papers)		763,697		65,874
Bonds and other fixed income		108,791		144,502
		872,488		210,376
Other investments - Non-current
Bonds and other fixed income		239,422		18,012
Others		7,660		6,922
		247,082		24,934

Note 20 - Borrowings

12 Months Ended

Dec. 31, 2020

Borrowings [abstract]

Note 20 - Borrowings

20 Borrowings

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
Non-current
Bank borrowings		315,884			40,896
Costs of issue of debt		(145	)		(16	)
		315,739			40,880
Current
Bank borrowings		303,170			781,258
Bank overdrafts		98			24
Costs of issue of debt		-			(10	)
		303,268			781,272
Total Borrowings		619,007			822,152

The maturity of borrowings is as follows:

(all amounts in thousands of U.S. dollars)

	1 year or less		1 - 2 years		2 – 3 years		3 - 4 years		4 - 5 years		Over 5 years		Total
At December 31, 2020
Borrowings		303,268		104,147		207,595		3,997		-		-		619,007
Total borrowings		303,268		104,147		207,595		3,997		-		-		619,007

Interest to be accrued (*)		9,829		5,068		1,014		22		-		-		15,933
Total		313,097		109,215		208,609		4,019		-		-		634,940

	1 year or less		1 - 2 years		2 – 3 years		3 - 4 years		4 - 5 years		Over 5 years		Total
At December 31, 2019
Borrowings		781,272		17,307		23,573		-		-		-		822,152
Total borrowings		781,272		17,307		23,573		-		-		-		822,152

Interest to be accrued (*)		11,370		1,045		117		-		-		-		12,532
Total		792,642		18,352		23,690		-		-		-		834,684

(*) Includes the effect of hedge accounting.

Significant borrowings include:

			In million of U.S. dollars
Disbursement date	Borrower	Type	Original & Outstanding	Final maturity
2020	Maverick	Bilateral	50	2021
2020	Maverick	Bilateral	75	2022
2020	Tamsa	Bilateral	60	2023
2020	Tamsa	Bilateral	80	2023
2020	Tamsa	Bilateral	60	2023
2020	SSPC	Multiple Banks	81	2021 - 2024

As of December 31, 2020, Tenaris was in compliance with all of its covenants.

The weighted average interest rates before tax shown below were calculated using the rates set for each instrument in its corresponding currency as of December 31, 2020 and 2019, considering hedge accounting where applicable.

		2020				2019
Total borrowings			2.51	%			3.18	%

Breakdown of long-term borrowings by currency and rate is as follows:

Non-current borrowings

(all amounts in thousands of U.S. dollars)			Year ended December 31,
Currency	Interest rates	2020		2019
USD	Variable		274,600		-
USD	Fixed		17,936		18,370
SAR	Fixed		20,902		16,106
EUR	Fixed		1,828		5,108
EUR	Variable		473		1,296
Total non-current borrowings			315,739		40,880

Breakdown of short-term borrowings by currency and rate is as follows:

Current borrowings

(all amounts in thousands of U.S. dollars)			Year ended December 31,
Currency	Interest rates	2020		2019
USD	Variable		67,823		17,092
USD	Fixed		2,322		274,799
EUR	Variable		1,015		80
EUR	Fixed		3,886		3,772
MXN	Fixed		147,997		424,964
ARS	Fixed		3,699		86
SAR	Variable		37,776		35,666
SAR	Fixed		38,750		24,797
Others	Variable		-		16
Total current borrowings			303,268		781,272

Borrowings evolution

		Year ended December 31, 2020
(all amounts in thousands of U.S. dollars)	Non current			Current
At the beginning of the year		40,880			781,272
Translation differences		266			(487	)
Proceeds and repayments, net		234,455			(478,913	)
Interests accrued less payments		426			(12,016	)
Reclassifications		(12,940	)		12,940
Increase due to business combinations		52,652			398
Overdrafts variation		-			74
At the end of the year		315,739			303,268

Note 21 - Deferred Income Tax

12 Months Ended

Dec. 31, 2020

Disclosure of temporary difference, unused tax losses and unused tax credits [abstract]

Note 21 - Deferred Income Tax

21 Deferred income tax

Deferred income taxes are calculated in full on temporary differences under the liability method using the tax rate of each country.

The evolution of deferred tax assets and liabilities during the year are as follows:

Deferred tax liabilities

(all amounts in thousands of U.S. dollars)	Fixed assets			Inventories			Intangible and Other			Total
At the beginning of the year		651,339			19,396			118,062			788,797
Translation differences		1,644			-			253			1,897
Increase due to business combinations		89,306			-			43,397			132,703
Charged to other comprehensive income		-			-			(1,194	)		(1,194	)
Income statement (credit)		(39,874	)		(4,141	)		(34,725	)		(78,740	)
At December 31, 2020		702,415			15,255			125,793			843,463

(all amounts in thousands of U.S. dollars)	Fixed assets			Inventories			Intangible and Other			Total
At the beginning of the year		710,995			25,048			46,532			782,575
Translation differences		(347	)		-			(4	)		(351	)
Increase due to business combinations		5,621			-			11,209			16,830
Charged to other comprehensive income		-			-			423			423
Income statement charge / (credit)		(64,930	)		(5,652	)		59,902			(10,680	)
At December 31, 2019		651,339			19,396			118,062			788,797

Deferred tax assets

(all amounts in thousands of U.S. dollars)	Provisions and allowances			Inventories			Tax losses			Other			Total
At the beginning of the year		(19,653	)		(93,404	)		(382,832	)		(181,606	)		(677,495	)
Translation differences		1,804			513			1,996			644			4,957
Increase due to business combinations		(7,452	)		(24,580	)		(33,598	)		(34,974	)		(100,604	)
Charged to other comprehensive income		-			-			-			(1,952	)		(1,952	)
Income statement charge / (credit)		4,093			31,534			(65,715	)		10,930			(19,158	)
At December 31, 2020		(21,208	)		(85,937	)		(480,149	)		(206,958	)		(794,252	)

(all amounts in thousands of U.S. dollars)	Provisions and allowances			Inventories			Tax losses			Other			Total
At the beginning of the year		(16,116	)		(86,585	)		(396,257	)		(86,184	)		(585,142	)
Translation differences		362			306			497			286			1,451
Increase due to business combinations		(1,160	)		(1,413	)		(1,172	)		(2,238	)		(5,983	)
Charged to other comprehensive income		-			-			-			(1,261	)		(1,261	)
Income statement charge / (credit)		(2,739	)		(5,712	)		14,100			(92,209	)		(86,560	)
At December 31, 2019		(19,653	)		(93,404	)		(382,832	)		(181,606	)		(677,495	)

In 2019 the effect of the adoption of IFRS 16 has been recognized as “Other” both for deferred tax assets and liabilities.

Deferred tax assets related to taxable losses of Tenaris subsidiaries are recognized to the extent it is considered probable that future taxable profits will be available against which such losses can be utilized in the foreseeable future. This amount includes $438.8 million related to U.S. subsidiaries mainly due to the recognition of accelerated fiscal depreciations, as well as the amounts related to the acquisition of IPSCO. The U.S. subsidiaries have incurred in fiscal losses in the past years. The remaining balance mainly corresponds to Tenaris’s Colombian, Japanese, Canadian and Saudi Arabian subsidiaries. These subsidiaries have incurred in fiscal losses in the past one or two years. Tenaris has concluded that these deferred tax assets will be recoverable based on the business plans and budgets.

The expiration dates of the recognized tax losses in less than 1 year, between 2 and 5 years and in more than 5 years is approximately 0%, 1.7% and 98.3% respectively.

As of December 31, 2020, the net unrecognized deferred tax assets amounted to $173.7 million. The expiration dates of the unrecognized tax losses less than 1 year, between 2 and 5 years and more than 5 years is approximately 4.6%, 17.1% and 78.3% respectively.

The estimated recovery analysis of deferred tax assets and deferred tax liabilities is as follows:

(all amounts in thousands of U.S. dollars)		Year ended December 31,
	2020			2019
Deferred tax assets to be recovered after 12 months		(640,603	)		(538,274	)
Deferred tax liabilities to be settled after 12 months		840,892			766,852

Deferred income tax assets and liabilities are offset when (1) there is a legally enforceable right to set-off current tax assets against current tax liabilities and (2) when the deferred income taxes relate to the same fiscal authority on either the same taxable entity or different taxable entities where there is an intention to settle the balances on a net basis. The following amounts, determined after appropriate set-off, are shown in the Consolidated Statement of Financial Position:

(all amounts in thousands of U.S. dollars)		Year ended December 31,
	2020			2019
Deferred tax assets		(205,590	)		(225,680	)
Deferred tax liabilities		254,801			336,982
		49,211			111,302

The movement in the net deferred income tax liability account is as follows:

		Year ended December 31,
	2020			2019
At the beginning of the year		111,302			197,433
Translation differences		6,854			1,100
Increase due to business combinations		32,099			10,847
Charged to other comprehensive income		(3,146	)		(838	)
Income statement (credit)		(97,898	)		(97,240	)
At the end of the year		49,211			111,302

Note 22 - Other Liabilities

12 Months Ended

Dec. 31, 2020

Disclosure of Other Liabilities [Abstract]

Note 22 - Other Liabilities

22 Other liabilities

(i) Other liabilities – Non current

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020		2019
Post-employment benefits		136,811		144,993
Other-long term benefits		64,928		85,473
Miscellaneous		43,896		20,917
		245,635		251,383

Post-employment benefits

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020		2019
Unfunded		115,774		125,573
Funded		21,037		19,420
		136,811		144,993

Unfunded

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
Values at the beginning of the year		125,573			97,318
Current service cost		4,796			7,978
Interest cost		6,496			5,526
Curtailments and settlements		(1,237	)		-
Remeasurements (*)		(2,230	)		7,010
Translation differences		(415	)		(1,567	)
Increase due to business combinations		1,566			15,660
Benefits paid from the plan		(22,955	)		(9,328	)
Other		4,180			2,976
At the end of the year		115,774			125,573

(*) For 2020 a loss of $1.6 million is attributable to demographic assumptions and a gain of $3.8 million to financial assumptions. For 2019 a loss of $1.3 million is attributable to demographic assumptions and a loss of $5.7 million to financial assumptions.

The actuarial assumptions for the most relevant plans were as follows:

	Year ended December 31,
	2020	2019
Discount rate	1% - 7%	1% - 7%
Rate of compensation increase	0% - 3%	0% - 3%

As of December 31, 2020, an increase / (decrease) of 1% in the discount rate assumption of the main plans would have generated a (decrease) / increase on the defined benefit obligation of $6.0 million and $7.2 million respectively, and an increase / (decrease) of 1% in the rate of compensation assumption of the main plans would have generated an increase / (decrease) impact on the defined benefit obligation of $3.1 million and $2.8 million respectively. The above sensitivity analyses are based on a change in discount rate and rate of compensation while holding all other assumptions constant. In practice, this is unlikely to occur, and changes in some of the assumptions may be correlated.

Funded

The amounts recognized in the statement of financial position for the current annual period and the previous annual period are as follows:

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
Present value of funded obligations		176,309			160,412
Fair value of plan assets		(157,335	)		(145,160	)
Liability (*)		18,974			15,252

(*) In 2020 and 2019, $2.1 million and $4.2 million corresponding to a plan with a surplus balance were reclassified within other non-current assets, respectively.

The movement in the present value of funded obligations is as follows:

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
At the beginning of the year		160,412			146,885
Translation differences		2,148			4,542
Current service cost		850			721
Interest cost		5,009			5,754
Remeasurements (*)		18,025			12,769
Benefits paid		(9,266	)		(10,259	)
Other		(869	)		-
At the end of the year		176,309			160,412

(*) For 2020 a loss of $3.7 million is attributable to demographic assumptions and a loss of $14.3 million to financial assumptions.

For 2019 a loss of $0.4 million is attributable to demographic assumptions and a loss of $12.4 million to financial assumptions.

The movement in the fair value of plan assets is as follows:

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
At the beginning of the year		(145,160	)		(132,438	)
Translation differences		(1,729	)		(4,137	)
Return on plan assets		(4,411	)		(5,018	)
Remeasurements		(10,396	)		(10,507	)
Contributions paid to the plan		(5,017	)		(3,589	)
Benefits paid from the plan		9,266			10,259
Other		112			270
At the end of the year		(157,335	)		(145,160	)

The major categories of plan assets as a percentage of total plan assets are as follows:

		Year ended December 31,
	2020			2019
Equity instruments		49.3	%		49.0	%
Debt instruments		46.8	%		47.0	%
Others		3.9	%		4.0	%

The actuarial assumptions for the most relevant plans were as follows:

	Year ended December 31,
	2020	2019
Discount rate	1 % - 3 %	3 % - 4 %
Rate of compensation increase	0 % - 3 %	0 % - 3 %

The expected return on plan assets is determined by considering the expected returns available on the assets underlying the current investment policy. Expected return on plan assets is determined based on long-term, prospective rates of return as of the end of the reporting period.

As of December 31, 2020, an increase / (decrease) of 1% in the discount rate assumption of the main plans would have generated a (decrease) / increase on the defined benefit obligation of $19.7 million and $24.2 million respectively, and an increase / (decrease) of 1% in the compensation rate assumption of the main plans would have generated an increase / (decrease) on the defined benefit obligation of $1.9 million and $1.7 million respectively. The above sensitivity analyses are based on a change in discount rate and rate of compensation while holding all other assumptions constant. In practice, this is unlikely to occur, and changes in some of the assumptions may be correlated.

The employer contributions expected to be paid for the year 2021 amounts approximately to $2.8 million.

The methods and types of assumptions used in preparing the sensitivity analyses did not change compared to the previous period.

(ii) Other liabilities – current

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020		2019
Payroll and social security payable		175,175		153,009
Miscellaneous		27,651		23,255
		202,826		176,264

Note 23 - Non-current allowances and provisions

12 Months Ended

Dec. 31, 2020

Disclosure of Non-current allowances and provisions [Abstract]

Note 23 - Non-current allowances and provisions

23 Non-current allowances and provisions

Liabilities

		Year ended December 31,
	2020			2019
(all amounts in thousands of U.S. dollars)
Values at the beginning of the year		54,599			36,089
Translation differences		(5,739	)		(1,571	)
Increase due to business combinations		26,542			-
Additional provisions		478			19,904
Reclassifications		557			5,641
Used		(3,219	)		(5,464	)
Values at the end of the year		73,218			54,599

Note 24 - Current allowances and provisions

12 Months Ended

Dec. 31, 2020

Disclosure of Current allowances and provisions [Abstract]

Note 24 - Current allowances and provisions

24 Current allowances and provisions

(i) Deducted from assets

Year ended December 31, 2020	Allowance for doubtful accounts - Trade receivables			Allowance for other doubtful accounts - Other receivables			Allowance for inventory obsolescence
(all amounts in thousands of U.S. dollars)
Values at the beginning of the year		(48,782	)		(4,892	)		(217,717	)
Translation differences		(37	)		801			1,560
Increase due to business combinations		(1,930	)		-			(76,776	)
(Additional) allowances		(4,644	)		(1,263	)		(35,809	)
Used		1,717			1,437			65,107
At December 31, 2020		(53,676	)		(3,917	)		(263,635	)

Year ended December 31, 2019	Allowance for doubtful accounts - Trade receivables			Allowance for other doubtful accounts - Other receivables			Allowance for inventory obsolescence
(all amounts in thousands of U.S. dollars)
Values at the beginning of the year		(66,535	)		(6,784	)		(209,796	)
Translation differences		9			88			794
Increase due to business combinations		(1,788	)		-			(10,761	)
(Additional) / reversals allowances		16,256			1,239			(29,138	)
Used		3,276			565			31,184
At December 31, 2019		(48,782	)		(4,892	)		(217,717	)

(ii) Liabilities

Year ended December 31, 2020	Sales risks			Other claims and contingencies (*)			Total
(all amounts in thousands of U.S. dollars)
Values at the beginning of the year		5,867			11,150			17,017
Translation differences		(5	)		(975	)		(980	)
Increase due to business combinations		116			398			514
Additional provisions		9,728			1,751			11,479
Reclassifications		-			(557	)		(557	)
Used		(13,911	)		(1,283	)		(15,194	)
At December 31, 2020		1,795			10,484			12,279

Year ended December 31, 2019	Sales risks			Other claims and contingencies (*)			Total
(all amounts in thousands of U.S. dollars)
Values at the beginning of the year		6,814			17,469			24,283
Translation differences		(28	)		(570	)		(598	)
Increase due to business combinations		505			8,000			8,505
Additional / (reversals) provisions		11,880			(3,219	)		8,661
Reclassifications		-			(5,641	)		(5,641	)
Used		(13,304	)		(4,889	)		(18,193	)
At December 31, 2019		5,867			11,150			17,017

(*) Other claims and contingencies mainly include lawsuits and other legal proceedings, including employee, tax and environmental-related claims.

Note 25 - Derivative Financial Instruments

12 Months Ended

Dec. 31, 2020

Disclosure of detailed information about financial instruments [abstract]

Note 25 - Derivative Financial Instruments

25 Derivative financial instruments

Net fair values of derivative financial instruments

The net fair values of derivative financial instruments, in accordance with IFRS 13, are:

(all amounts in thousands of U.S. dollars)		Year ended December 31,
	2020			2019
Derivatives hedging borrowings and investments		10,119			19,000
Other Derivatives		1,330			929
Contracts with positive fair values		11,449			19,929

Derivatives hedging borrowings and investments		(2,250	)		-
Other Derivatives		(967	)		(1,814	)
Contracts with negative fair values		(3,217	)		(1,814	)
Total		8,232			18,115

Foreign exchange derivative contracts and hedge accounting

Tenaris applies hedge accounting to certain cash flow hedges of highly probable forecast transactions. The net fair values of exchange rate derivatives and those derivatives that were designated for hedge accounting as of December 31, 2020 and 2019 were as follows:

(all amounts in thousands of U.S. dollars)				Fair Value						Hedge Accounting Reserve
Purchase currency	Sell currency	Term	2020			2019			2020			2019
MXN	USD	2021		9,838			18,999			156			404
USD	MXN	2021		(5	)		(576	)		-			-
USD	EUR	2021		(1,969	)		-			5			-
EUR	USD	2021		543			588			-			-
JPY	USD	2021		-			(190	)		-			-
USD	BRL	2021		412			(234	)		85			-
JPY	USD	2030		94			-			(4,958	)		2,149
USD	KWD	2021		(246	)		103			(59	)		38
USD	CAD	2021		-			(200	)		-			-
USD	COP	2021		-			(345	)		-			-
USD	CNY	2021		(482	)		(167	)		-			-
Others		2021		47			137			-			-
Total				8,232			18,115			(4,771	)		2,591

Following is a summary of the hedge reserve evolution:

(all amounts in thousands of U.S. dollars)

	Equity Reserve Dec-18			Movements 2019		Equity Reserve Dec-19		Movements 2020			Equity Reserve Dec-20
Foreign Exchange		(916	)		3,507		2,591		(7,362	)		(4,771	)
Total Cash flow Hedge		(916	)		3,507		2,591		(7,362	)		(4,771	)

Tenaris estimates that the cash flow hedge reserve corresponding to derivatives instruments at December 31, 2020 will be recycled to the Consolidated Income Statement during 2021. For information on hedge accounting reserve, see Section III.D.

Note 26 - Contingencies, Commitments and Restrictions On the Distribution of Profits	12 Months Ended
	Dec. 31, 2020
Disclosure of Contingencies, Commitments and Restrictions on Distribution of Profits [Abstract]
Note 26 - Contingencies, Commitments and Restrictions On the Distribution of Profits	26 Contingencies, commitments and restrictions on the distribution of profits (i) Contingencies Tenaris is from time to time subject to various claims, lawsuits and other legal proceedings, including customer, employee, tax and environmental-related claims, in which third parties are seeking payment for alleged damages, reimbursement for losses, or indemnity. Management with the assistance of legal counsel periodically reviews the status of each significant matter and assesses potential financial exposure. Some of these claims, lawsuits and other legal proceedings involve highly complex issues, and often these issues are subject to substantial uncertainties and, therefore, the probability of loss and an estimation of damages are difficult to ascertain. Accordingly, with respect to a large portion of such claims, lawsuits and other legal proceedings, the Company is unable to make a reliable estimate of the expected financial effect that will result from ultimate resolution of the proceeding. In those cases, the Company has not accrued a provision for the potential outcome of these cases. If a potential loss from a claim, lawsuit or other proceeding is considered probable and the amount can be reasonably estimated, a provision is recorded. Accruals for loss contingencies reflect a reasonable estimate of the losses to be incurred based on information available to management as of the date of preparation of the financial statements and take into consideration litigation and settlement strategies. In a limited number of ongoing cases, the Company was able to make a reliable estimate of the expected loss or range of probable loss and has accrued a provision for such loss but believes that publication of this information on a case-by-case basis would seriously prejudice the Tenaris’s position in the ongoing legal proceedings or in any related settlement discussions. Accordingly, in these cases, the Company has disclosed information with respect to the nature of the contingency but has not disclosed its estimate of the range of potential loss. The Company believes that the aggregate provisions recorded for potential losses in these Consolidated Financial Statements are adequate based upon currently available information. However, if management’s estimates prove incorrect, current reserves could be inadequate and the Company could incur a charge to earnings which could have a material adverse effect on its results of operations, financial condition, net worth and cash flows. Below is a summary description of Tenaris’s material legal proceedings which are outstanding as of the date of these Consolidated Financial Statements. In addition, the Company is subject to other legal proceedings, none of which is believed to be material. CSN claims relating to the January 2012 acquisition of Usiminas shares Confab, a Brazilian subsidiary of the Company, is one of the defendants in a lawsuit filed in Brazil by Companhia Siderúrgica Nacional (“CSN”) and various entities affiliated with CSN against Confab and several Ternium subsidiaries that acquired a participation in Usiminas’ control group in January 2012. The CSN lawsuit alleges that, under applicable Brazilian laws and rules, the acquirers were required to launch a tag-along tender offer to all non-controlling holders of Usiminas’ ordinary shares for a price per share equal to 80% of the price per share paid in such acquisition, or BRL28.8, and seeks an order to compel the acquirers to launch an offer at that price plus interest. If so ordered, the offer would need to be made to 182,609,851 ordinary shares of Usiminas not belonging to Usiminas’ control group, and Confab would have a 17.9% share in that offer. CSN claims relating to the January 2012 acquisition of Usiminas shares (Cont.) On September 23, 2013, the first instance court dismissed the CSN lawsuit, and on February 8, 2017, the court of appeals maintained the understanding of the first instance court. On March 6, 2017, CSN filed a motion for clarification against the decision of the Court of Appeals of São Paulo, which was rejected on July 19, 2017. On August 18, 2017, CSN filed an appeal to the Superior Court of Justice seeking the review and reversal of the decision issued by the Court of Appeals. On March 5, 2018, the court of appeals ruled that CSN’s appeal did not meet the requirements for submission to the Superior Court of Justice and rejected the appeal. On May 8, 2018, CSN appealed against such ruling and on January 22, 2019, the court of appeals rejected it and ordered that the case be submitted to the Superior Court of Justice. On September 10, 2019, the Superior Court of Justice declared CSN’s appeal admissible. The Superior Court of Justice will review the case and then render a decision on the merits. The Superior Court of Justice is restricted to the analysis of alleged violations to federal laws and cannot assess matters of fact. The Company continues to believe that all of CSN’s claims and allegations are groundless and without merit, as confirmed by several opinions of Brazilian legal counsel, two decisions issued by the Brazilian securities regulator (“CVM”) in February 2012 and December 2016, and the first and second instance court decisions referred to above. Veracel celulose accident litigation On September 21, 2007, an accident occurred in the premises of Veracel Celulose S.A. (“Veracel”) in connection with a rupture in one of the tanks used in an evaporation system manufactured by Confab. The Veracel accident allegedly resulted in material damages to Veracel. Itaú Seguros S.A. (“Itaú”), Veracel’s insurer at the time of the Veracel accident and then replaced by Chubb Seguros Brasil S/A (“Chubb”), initiated a lawsuit against Confab seeking reimbursement of damages paid to Veracel in connection with the Veracel accident. Veracel initiated a second lawsuit against Confab seeking reimbursement of the amount paid as insurance deductible with respect to the Veracel accident and other amounts not covered by insurance. Itaú and Veracel claimed that the Veracel accident was caused by failures and defects attributable to the evaporation system manufactured by Confab. Confab believes that the Veracel accident was caused by the improper handling by Veracel’s personnel of the equipment supplied by Confab in violation of Confab’s instructions. The two lawsuits were consolidated and are considered by the 6th Civil Court of São Caetano do Sul. However, each lawsuit will be adjudicated separately. On September 28, 2018 Confab and Chubb entered into a settlement agreement pursuant to which on October 9, 2018, Confab paid an amount of approximately $3.5 million to Chubb, without assuming any liability for the accident or the claim. On October 10, 2018, Confab was notified that the court had issued rulings for both lawsuits. Both decisions were unfavorable to Confab: With respect to Chubb’s claim, on October 9, 2018, Confab paid an amount of approximately BRL13.1 million (approximately $3.5 million at historical exchange rate), including interest, fees and expenses, settling the Chubb claim in full. With respect to Veracel’s claim, Confab was ordered to pay the insurance deductible and other concepts not covered by insurance, currently estimated to amount to BRL69.9 million (approximately $13.5 million) including interest, fees and expenses. Both parties filed motions for clarification against the court’s decision, which were partially granted. Although the contract between Confab and Veracel expressly provided that Confab would not be liable for damages arising from lost profits, the court award would appear to include BRL59.9 million (approximately $11.5 million) of damages arising therefrom. Confab has additional defense arguments in respect of a claim for lost profits. On December 18, 2018, Confab filed an appeal against the first instance court decision, and on April 30, 2019, Veracel filed its response to the appeal. At this stage the Company cannot predict the outcome of the claim or the amount or range of loss in case of an unfavorable outcome. *Ongoing investigation* The Company is aware that Brazilian, Italian and Swiss authorities have been investigating whether certain payments were made prior to 2014 from accounts of entities presumably associated with affiliates of the Company to accounts allegedly linked to individuals related to Petróleo Brasileiro S.A. (“Petrobras”) and whether any such payments were intended to benefit the Company’s Brazilian subsidiary Confab. Any such payments could violate certain applicable laws, including the U.S. Foreign Corrupt Practices Act. The Company had previously reviewed certain of these matters in connection with an investigation by the Brazilian authorities related to “Operation Lava Jato,” and did not uncover any information that corroborated allegations of involvement in these alleged payments by the Company or its subsidiaries. Furthermore, the Company became aware that a Petrobras internal investigation commission reviewed certain contracts with Confab and concluded that they had not found evidence that Petrobras had benefitted Confab or had misused applicable local content rules. The Audit Committee of the Company's Board of Directors engaged external counsel in connection with the Company’s review of these matters. In addition, the Company voluntarily notified the U.S. Securities and Exchange Commission (“SEC”) and the U.S. Department of Justice (“DOJ”) in October 2016. In July 2019, the Company learned that the public prosecutors’ office of Milan, Italy, had completed a preliminary investigation into the alleged payments and had included in the investigation, among other persons, the Company’s Chairman and Chief Executive Officer, two other board members, Gianfelice Rocca and Roberto Bonatti, and the Company’s controlling shareholder, San Faustin. The Company is not a party to the proceedings. In February 2020, the Company learned that the magistrate overseeing the investigation decided to move the case to trial. The Company’s outside counsel had previously reviewed the Italian prosecutors’ investigative file and has informed the Board that neither that file nor this magistrate’s decision sets forth evidence of involvement by any of the three directors in the alleged wrongdoing. Accordingly, the Board concluded that no particular action was warranted at that time, other than inviting the referred board members to continue discharging their respective responsibilities with the full support of the Board. The trial has not yet started. In June 2020, the Company learned that the Brazilian public prosecutors’ office requested the indictment of several individuals, including three executives or former executives of Confab and a former agent of Confab, charging them with the alleged crimes of corruption in relation to contracts executed between 2007 and 2010, and money laundering in relation to payments between 2009 and 2013. Neither the Company nor Confab is a party to the proceedings. The Company continues to respond to requests from and otherwise cooperate with the appropriate authorities. The Company has engaged in discussions with the SEC and the DOJ towards a potential resolution of the investigation. There are no assurances that the discussions with the SEC or the DOJ will result in a final resolution of the investigation or, if a resolution is achieved, the timing, scope and terms of any such resolution. At this time, the Company cannot predict the outcome of these matters or estimate the range of potential loss or extent of risk, if any, to the Company's business that may result from the resolution of these matters. *Putative class actions* Following the Company’s November 27, 2018 announcement that its Chairman and CEO Paolo Rocca had been included in an Argentine court investigation known as the Notebooks Case (a decision subsequently reversed by a higher court), two putative class action complaints were filed in the U.S. District Court for the Eastern District of New York. On April 29, 2019, the court consolidated the complaints into a single case, captioned “In re Tenaris S.A. Securities Litigation”, and appointed lead plaintiffs and lead counsel. On July 19, 2019, the lead plaintiffs filed an amended complaint purportedly on behalf of purchasers of Tenaris securities during the putative class period of May 1, 2014 through December 5, 2018. The individual defendants named in the complaint are Tenaris’s Chairman and CEO and Tenaris’s former CFO. The complaint alleges that during the class period, the Company and the individual defendants inflated the Tenaris share price by failing to disclose that the nationalization proceeds received by Ternium (in which the Company held an 11.46% stake) when Sidor was expropriated by Venezuela were received or expedited as a result of allegedly improper payments made to Argentine officials. The complaint does not specify the damages that plaintiff is seeking. On October 9, 2020, the court granted in part and denied in part the defendants’ motions to dismiss. The court partially granted and partially denied the motion to dismiss the claims against the Company and its Chairman and CEO. In addition, the court granted the motions to dismiss as to all claims against San Faustin, Techint, and Tenaris’s former CFO. The case will now proceed based on the claims that survived the motion to dismiss. Management believes the Company has meritorious defenses to these claims; however, at this stage Tenaris cannot predict the outcome of the claim or the amount or range of loss in case of an unfavorable outcome. *Investigation concerning alleged price overcharges in Brazil* In 2018, two Brazilian subsidiaries of the Company were notified of formal charges arising from a review by the Tribunal de Contas da Uniao (“TCU”) for alleged price overcharges on goods supplied to Petróleo Brasileiro S.A. - Petrobras under a supply contract. Both companies have already filed their defenses. On September 28, 2020, TCU’s technical unit, advised TCU that the alleged overprice should be reduced from BRL9 million (approximately $1.7 million) to BRL401 thousand (approximately $77 thousand), and further stated that because of its immateriality, the alleged overcharge should not give rise to any penalties or indemnification obligations and acknowledged that any potential penalties would be barred as a result of the applicable statute of limitations. On November 19, 2020 the Public Prosecutor’s Office filed an opinion supporting the TCU’s technical unit’s views. TCU’s final judgment is pending. The estimated amount of this claim is BRL30.6 million (approximately $5.9 million). The Company believes, based on the advice of counsel and external consultants, that the prices charged under the Petrobras contract do not result in overprices and that it is unlikely that the ultimate resolution of this matter will result in a material obligation. *Administrative proceeding concerning Brazilian tax credits* Confab is a party to an administrative proceeding concerning the recognition and transfer of tax credits for an amount allegedly exceeding the amount that Confab would have been entitled to recognize and / or transfer. The proceeding resulted in the imposition of a fine against Confab representing approximately 75% of the allegedly undue credits, which was appealed by Confab. On January 21, 2019, Confab was notified of an administrative decision denying Confab’s appeal, thereby upholding the tax determination and the fine against Confab. On January 28, 2019, Confab challenged such administrative decision and is currently awaiting a resolution. In case of an unfavorable resolution, Confab may still appeal before the courts. The estimated amount of this claim is BRL57.2 million (approximately $11 million). At this stage, the Company cannot predict the outcome of this claim. *U.S. patent infringement litigation* Tenaris Coiled Tubes, LLC (“TCT”), a U.S. subsidiary of the Company, was sued on 2017 by its competitor Global Tubing, alleging violations to certain intellectual property regulations and seeking a declaration that certain Global Tubing products do not infringe patents held by TCT. TCT filed a counterclaim seeking declaration that certain Global Tubing products infringe patents held by TCT, and Global Tubing responded alleging that such patents should be invalidated. On December 13, 2019, Global Tubing filed an amended complaint (including the Company as defendant) and alleging that TCT and the Company misled the patent office in order to monopolize the coiled tubing market for quench and tempered products. The trial is set for August 2021. At this time, it is not possible to predict the outcome of this matter or estimate the range of potential losses that may result from the resolution of this claim. *Tax assessment from Italian tax authorities* The Company’s Italian subsidiary, Dalmine, received on December 27, 2019, a tax assessment from the Italian tax authorities related to fiscal year 2014. As of December 31, 2020, the claim amounted to approximately EUR25.7 million (approximately $31.6 million), comprising EUR20.7 million (approximately $25.5 million) in principal and EUR5.0 million (approximately $6.1 million) in interest and penalties. In the report for a tax audit conducted in 2019, the Italian tax inspectors indicated that they also intend to bring claims for fiscal year 2015 with respect to the same matters; as of December 31, 2020, these additional claims would amount to approximately EUR10.5 million (approximately $12.9 million), comprising EUR8.1 million (approximately $10.0 million) in principal and EUR2.4 million (approximately $2.9 million) in interest and penalties. The claims mainly refer to the compensation for certain intercompany transactions involving Dalmine in connection with sales of products and R&D activities. On July 27, 2020, Dalmine filed a first-instance appeal before the Milan tax court against the 2014 tax assessment. Based on the advice of counsel, the Company believes that it is unlikely that the ultimate resolution of these matters will result in a material obligation. *Product liability litigation* The Company’s recently acquired U.S. subsidiary, IPSCO, or its subsidiaries, are parties to several product liability claims, which may result in damages for an aggregate amount estimated at approximately $17.6 million. This includes a lawsuit alleging product liability and negligent misrepresentation in which the plaintiff alleges that defects in certain casing provided by IPSCO resulted in three well failures causing damages for an amount of approximately $15 million. Although at this time the Company cannot predict the outcome of any of these matters, the Company believes that provisions have been recorded in an amount sufficient to cover potential exposure under these claims. (ii) Commitments and guarantees Set forth is a description of the Tenaris’s main outstanding commitments: An Argentine subsidiary of the Company entered into a contract with Transportadora de Gas del Norte S.A. for the service of natural gas transportation to its facilities. As of December 31, 2020, the aggregate commitment to take or pay the committed volumes for an original 9 -year term totalled approximately $16.8 million. Several of the Company’s subsidiaries entered into a contract with Praxair S.A. for the service of oxygen and nitrogen supply. As of December 31, 2020, the aggregate commitment to take or pay the committed volumes for an original 14-year term totalled approximately $31 million. Several of the Company’s subsidiaries entered into a contract with Graftech for the supply of graphite electrodes. As of December 31, 2020, the aggregate commitment to take or pay the committed volumes totalled approximately $10.9 million. A subsidiary of the Company entered into a 25-year contract (effective as of December 1, 2016, through December 1, 2041) with Techgen for the supply of 197 MW (which represents 22% of Techgen’s capacity). Monthly payments are determined on the basis of capacity charges, operation costs, back-up power charges, and transmission charges. As of the seventh contract year (as long as Techgen’s existing or replacing bank facility has been repaid in full), the Company’s subsidiary has the right to suspend or early terminate the contract if the rate payable under the agreement is higher than the rate charged by the Comisión Federal de Electricidad (“CFE”) or its successors. The Company’s subsidiary may instruct Techgen to sell to any affiliate, to CFE, or to any other third party all or any part of unused contracted energy under the agreement and the Company’s subsidiary will benefit from the proceeds of such sale. A subsidiary of the Company entered into a contract with Air Liquide Mexico, S. de R.L de C.V. for the supply of argon gas. As of December 31, 2020, the aggregate commitment totalled approximately $19 million. Tenaris Bay City, a U.S. subsidiary of the Company, is a party to a contract with Nucor Steel Memphis Inc. under which it is committed to purchase on a monthly basis a specified minimum volume of steel bars, at prices subject to quarterly adjustments. The contract will become effective upon delivery of the first purchase order, which has not yet occurred, and will remain in force for a 3 year term. As of December 31, 2020, the estimated aggregate contract amount calculated at current prices, is approximately $113.4 million. The contract gives Tenaris Bay City the right to temporarily reduce the quantities to be purchased thereunder to 75% of the agreed-upon minimum volume in cases of material adverse changes in prevailing economic or market conditions. In connection with the closing of the acquisition of IPSCO, a U.S. subsidiary of the Company, entered into a 6-year master distribution agreement (the “MDA”) with PAO TMK (“TMK”) whereby, since January 2, 2020, Tenaris is the exclusive distributor of TMK’s OCTG and line pipe products in United States and Canada. At the end of the MDA’s 6-years term, TMK will have the option to extend the duration of its term for an additional 12 month period. Under the MDA, the Company is required to purchase specified minimum volumes of TMK-manufactured OCTG and line pipe products, based on the aggregate market demand for the relevant product category in the United States in the relevant year. In light of the adverse scenario of declining oil and gas prices and unprecedented oversupply in the oil market, Tenaris and TMK have agreed to certain accommodations relating to the MDA’s minimum annual purchase requirement for 2020 to minimize the negative impact of the crisis on both parties. Because of this, no penalties will be applied for year 2020. As of December 31, 2020, the Company’s commitment under the MDA for the remainder of its 6-year term totalled approximately $498.3 million. In addition, Tenaris (i) applied for stand-by letters of credit as well as corporate guarantees covering certain obligations of Techgen as described in note 13 (c), (ii) issued corporate guarantees securing certain obligations of GPC, as described in note 13 (d); and (iii) issued performance guarantees mainly related to long term commercial contracts with several customers and parent companies for approximately $2.5 billion as of December 31, 2020. (iii) Restrictions to the distribution of profits and payment of dividends In accordance with Luxembourg Law, the Company is required to transfer a minimum of 5% of its net profit for each financial year to a legal reserve until such reserve equals 10% of the issued share capital. As of December 31, 2020, this reserve is fully allocated and additional allocations to the reserve are not required under Luxembourg law. Dividends may not be paid out of the legal reserve. The Company may pay dividends to the extent, among other conditions, that it has distributable retained earnings calculated in accordance with Luxembourg law and regulations.

Note 27 - Foreign exchange control measures in Argentina	12 Months Ended
	Dec. 31, 2020
Foreign exchange rates [abstract]
Note 27 - Foreign exchange control measures in Argentina	27 Foreign exchange control measures in Argentina Beginning in September 2019, the Argentine government has imposed and continues to impose significant restrictions on foreign exchange transactions. The main currently applicable measures are described below: Foreign currency proceeds derived from exports of goods must be sold into the Argentine foreign exchange market and converted into Argentine pesos within 60 days from shipment date (if made to related parties) or 180 days from shipment date (if made to unrelated parties), or within 5 days of collection, if collected earlier. Foreign currency proceeds from exports of services must be sold into the Argentine foreign exchange market and converted into Argentine pesos within 5 business days of collection. Access to the Argentine foreign exchange market to pay for imports of services rendered by related parties (including royalties) is subject to Argentine Central Bank approval. Access to the Argentine foreign exchange market to pay for imports of goods and services provided by third parties requires the importer not to have more than $100,000 deposited in any foreign account. In addition, it will have to declare it has not accessed the market to purchase bonds and sell them for foreign currency for a period of 90 days prior to the required payment of imports, and will not do so for a period of 90 days after the Argentine Central Bank provides the foreign currency. Access to the Argentine foreign exchange market to pay debt service (principal and interests) for financial debts with related parties requires prior Argentine Central Bank approval, unless such debts are obtained and sold into the Argentine foreign exchange market and converted into Argentine pesos after October 2, 2020 and carry an average life of no less than 2 years. Debts with foreign creditors larger than $1 million maturing between October 15, 2020 and March 31, 2021 will need to be refinanced in at least 60% of outstanding principal and for a minimum period of 2 years. Access to the Argentine foreign exchange market to make dividend payments generally requires prior Argentine Central Bank approval. When required, Argentine Central Bank approvals are granted on a very restricted basis. Tenaris’s Argentine subsidiaries continue to have access to the official foreign currency markets for their foreign exchange transactions. Therefore, assets and liabilities denominated in foreign currency as of December 31, 2020, have been valued at the prevailing official exchange rates. Tenaris’s financial position in Argentine peso as of December 31, 2020, amounted to a net short exposure of approximately $39.6 million. As of December 31, 2020, the total net equity of Argentine subsidiaries represented approximately 8% of the total equity of Tenaris and the sales performed by Argentine subsidiaries during the year ended on December 31, 2020 amounted approximately to 12% of Tenaris’s total sales. Management continues to monitor closely the evolution of the main variables affecting its business, identifying the potential impact thereof on its financial and economic situation and determining the appropriate course of action in each case. The Company’s Consolidated Financial Statements should be read taking into account these circumstances. As the context of volatility and uncertainty remains in place as of the issue date of these Consolidated Financial Statements, additional Argentine Central Bank regulations that could be imposed in the future could further restrict our Argentine subsidiary’s ability to access the official foreign exchange market.

Note 28 - Cash Flow Disclosures

12 Months Ended

Dec. 31, 2020

Disclosure of Cash Flow [Abstract]

Note 28 - Cash Flow Disclosures

28 Cash flow disclosures

(all amounts in thousands of U.S. dollars)

			Year ended December 31,
(i)	Changes in working capital	2020			2019			2018
	Inventories		828,796			311,459			(176,443	)
	Receivables and prepayments and current tax assets		74,877			(34,368	)		30,144
	Trade receivables		409,163			428,326			(517,579	)
	Other liabilities		(34,871	)		(18,295	)		(22,984	)
	Customer advances		(34,388	)		16,844			5,976
	Trade payables		(184,442	)		(180,857	)		(57,066	)
			1,059,135			523,109			(737,952	)
(ii)	Income tax accruals less payments
	Tax accrued		23,150			202,452			229,207
	Taxes paid		(140,364	)		(395,869	)		(170,713	)
			(117,214	)		(193,417	)		58,494
(iii)	Interest accruals less payments, net
	Interest accrued		8,627			(4,616	)		(2,914	)
	Interest received		19,613			30,890			40,613
	Interest paid		(28,778	)		(30,655	)		(31,548	)
			(538	)		(4,381	)		6,151

Note 29 - Related Party Transactions

12 Months Ended

Dec. 31, 2020

Disclosure of transactions between related parties [abstract]

Note 29 - Related Party Transactions

29 Related party transactions

As of December 31, 2020:

San Faustin owned 713,605,187 shares in the Company, representing 60.45% of the Company’s capital and voting rights.

San Faustin owned all of its shares in the Company through its wholly-owned subsidiary Techint Holdings S.à.r.l., a Luxembourg société à responsabilité limitée (“Techint”), who is the holder of record of the above-mentioned Tenaris shares.

Rocca & Partners Stichting Administratiekantoor Aandelen San Faustin, a private foundation located in the Netherlands (Stichting) (“RP STAK”) held voting shares in San Faustin sufficient in number to control San Faustin.

No person or group of persons controls RP STAK.

Based on the information most recently available to the Company, Tenaris’s directors and senior management as a group owned 0.08% of the Company’s outstanding shares.

Transactions and balances disclosed as with “non-consolidated parties” are those with companies over which Tenaris exerts significant influence or joint control in accordance with IFRS, but does not have control. All other transactions and balances with related parties which are not non-consolidated parties and which are not consolidated are disclosed as “Other”. The following transactions were carried out with related parties:

	(all amounts in thousands of U.S. dollars)		Year ended December 31,
		2020		2019		2018
(i)	Transactions
	(a) Sales of goods and services
	Sales of goods to non-consolidated parties		20,183		20,577		23,709
	Sales of goods to other related parties		18,243		69,972		131,548
	Sales of services to non-consolidated parties		5,829		5,620		7,641
	Sales of services to other related parties		5,049		4,386		5,647
			49,304		100,555		168,545
	(b) Purchases of goods and services
	Purchases of goods to non-consolidated parties		84,485		174,588		245,186
	Purchases of goods to other related parties		12,892		51,765		106,624
	Purchases of services to non-consolidated parties		6,979		9,404		9,556
	Purchases of services to other related parties		18,133		54,514		46,179
			122,489		290,271		407,545

	(all amounts in thousands of U.S. dollars)		At December 31,
		2020			2019
(ii)	Period-end balances
	(a) Arising from sales / purchases of goods / services
	Receivables from non-consolidated parties		78,721			78,884
	Receivables from other related parties		4,447			10,400
	Payables to non-consolidated parties		(24,914	)		(19,100	)
	Payables to other related parties		(2,310	)		(7,048	)
			55,944			63,136
	(b) Financial debt
	Finance lease liabilities from non-consolidated parties		(2,042	)		(2,064	)
	Finance lease liabilities from other related parties		(810	)		-
			(2,852	)		(2,064	)

In addition to the tables above, the Company issued various guarantees in favor of Techgen and GPC; for further details, please see note 13 (c and d) and note 26 (ii). No other material guarantees were issued in favor of other related parties.

Directors’ and senior management compensation

During the years ended December 31, 2020, 2019 and 2018, the cash compensation of Directors and Senior managers amounted to $27.4 million, $33.7 million and $33.7 million respectively. These amounts include cash benefits paid to certain senior managers in connection with the pre-existing retirement plans. In addition, Directors and Senior managers received 522, 468 and 558 thousand units for a total amount of $5.0 million, $4.8 million and $5.6 million respectively in connection with the Employee retention and long term incentive program mentioned in note II.P.3 Employee benefits – Other long term benefits.

Note 30 - Fees Paid to the Company's Principal Accountant

12 Months Ended

Dec. 31, 2020

Additional information [abstract]

Note 30 - Fees Paid to the Company's Principal Accountant

30 Fees paid to the Company's principal accountant

Total fees accrued for professional services rendered by PwC Network firms to Tenaris S.A. and its subsidiaries are detailed as follows:

(all amounts in thousands of U.S. dollars)		Year ended December 31,
	2020		2019		2018
Audit fees		3,781		3,846		3,841
Audit-related fees		134		50		43
Tax fees		102		7		-
All other fees		-		1		7
Total		4,017		3,904		3,891

Note 31 - Principal Subsidiaries

12 Months Ended

Dec. 31, 2020

Principal subsidiaries

Note 31 - Principal Subsidiaries

31 Principal subsidiaries

The following is a list of Tenaris’s principal subsidiaries and its direct and indirect percentage of ownership of each controlled company at December 31, 2020.

Company	Country of Incorporation	Main activity	Percentage of ownership at December 31, (*)
Company	Country of Incorporation	Main activity	2020	2019	2018
ALGOMA TUBES INC.	Canada	Manufacturing of seamless steel pipes	100%	100%	100%
CONFAB INDUSTRIAL S.A. and subsidiaries	Brazil	Manufacturing of welded steel pipes and capital goods	100%	100%	100%
DALMINE S.p.A.	Italy	Manufacturing of seamless steel pipes	100%	100%	100%
HYDRIL COMPANY and subsidiaries (except detailed) (a)	USA	Manufacture and marketing of premium connections	100%	100%	100%
IPSCO TUBULARS INC. and subsidiaries	USA	Manufacturing of welded and seamless steel pipes	100%	NA	NA
KAZAKHSTAN PIPE THREADERS LIMITED LIABILITY PARTNERSHIP	Kazakhstan	Threading of premium products	100%	100%	100%
MAVERICK TUBE CORPORATION and subsidiaries	USA	Manufacturing of welded steel pipes	100%	100%	100%
NKKTUBES	Japan	Manufacturing of seamless steel pipes	51%	51%	51%
P.T. SEAMLESS PIPE INDONESIA JAYA	Indonesia	Manufacturing of seamless steel products	89%	89%	89%
PRUDENTIAL STEEL LTD. (b)	Canada	Manufacturing of welded steel pipes	100%	100%	100%
S.C. SILCOTUB S.A.	Romania	Manufacturing of seamless steel pipes	100%	100%	100%
SAUDI STEEL PIPE CO.	Saudi Arabia	Manufacturing of welded steel pipes	48%	48%	NA
SIAT SOCIEDAD ANONIMA	Argentina	Manufacturing of welded and seamless steel pipes	100%	100%	100%
SIDERCA SOCIEDAD ANONIMA INDUSTRIAL Y COMERCIAL and subsidiaries	Argentina	Manufacturing of seamless steel pipes	100%	100%	100%
TALTA - TRADING E MARKETING SOCIEDADE UNIPESSOAL LDA.	Portugal	Holding Company	100%	100%	100%
TENARIS BAY CITY, INC.	USA	Manufacturing of seamless steel pipes	100%	100%	100%
TENARIS CONNECTIONS BV	Netherlands	Development, management and licensing of intellectual property	100%	100%	100%
TENARIS FINANCIAL SERVICES S.A.	Uruguay	Financial company	100%	100%	100%
TENARIS GLOBAL SERVICES (CANADA) INC.	Canada	Marketing of steel products	100%	100%	100%
TENARIS GLOBAL SERVICES (U.S.A.) CORPORATION	USA	Marketing of steel products	100%	100%	100%
TENARIS GLOBAL SERVICES (UK) LTD	United Kingdom	Holding company and marketing of steel products	100%	100%	100%
TENARIS GLOBAL SERVICES S.A. and subsidiaries (except detailed) (c)	Uruguay	Holding company and marketing of steel products	100%	100%	100%
TENARIS INVESTMENTS (NL) B.V. and subsidiaries	Netherlands	Holding company	100%	100%	NA
TENARIS INVESTMENTS S.àr.l.	Luxembourg	Holding company	100%	100%	100%
TENARIS TUBOCARIBE LTDA.	Colombia	Manufacturing of welded and seamless steel pipes	100%	100%	100%
TUBOS DE ACERO DE MEXICO, S.A.	Mexico	Manufacturing of seamless steel pipes	100%	100%	100%

(*) All percentages rounded.

(a) Tenaris Investments S.a.r.l. holds 100 % of Hydril's subsidiaries shares except for Technical Drilling & Production Services Nigeria. Ltd where it held 80% for 2019 and 2018.

(b) See note 36.

(c) Tenaris holds 97.5% of Tenaris Supply Chain S.A. and 40% of Tubular Technical Services Ltd. and Pipe Coaters Nigeria Ltd., 49% of Amaja Tubular Services Limited, 49% of Tubular Services Angola Lda and 60% of Tenaris Baogang Baotou Steel Pipes Ltd.

Note 32 - Business Combinations

12 Months Ended

Dec. 31, 2020

Disclosure of detailed information about business combination [abstract]

Note 32 - Business Combinations

32 Business combinations

Acquisition of IPSCO Tubulars, Inc.

Acquisition and price determination

On January 2, 2020, Tenaris acquired 100% of the shares of IPSCO, a U.S. manufacturer of steel pipes, from PAO TMK (“TMK”). The acquisition price was determined on a cash-free, debt-free basis, and the amount paid in cash at the closing, following contractual adjustments for cash, indebtedness, working capital and certain other items as estimated by the seller as of the closing date, was $1,067 million. The final acquisition price was subject to a contractual true-up adjustment based on actual amounts of cash, indebtedness, working capital and certain other items as of the closing date. On June 25, 2020 Tenaris and PAO TMK signed a Letter Agreement in which they settled the discussions regarding certain adjustments on the transaction price. The parties finally determined the closing price in an amount equal to $1,029 million, which is less than the closing price paid by an amount equal to $38.5 million. This amount was collected on July 2, 2020 and this agreement implies that all disputes relating to the closing statement were resolved.

IPSCO’s facilities are located mainly in the midwestern and northeastern regions of the country. IPSCO’s steel shop in Koppel, Pennsylvania, is Tenaris’s first in the United States, providing vertical integration through domestic production of a relevant part of its steel bar needs. The Ambridge, Pennsylvania, mill adds a second seamless manufacturing facility and complements Tenaris’s seamless plant in Bay City, Texas. Given the abrupt and steep decline in market demand in 2020, all of IPSCO’s facilities were temporarily closed but some of them are expected to resume operations during the 2021 as market continues to improve.

In connection with the closing of the transaction, subsidiaries of Tenaris and TMK entered into a 6-year master distribution agreement (the “MDA”) for more information see note 26 (ii).

The Company has begun consolidating IPSCO’s balances and results of operations as from January 2, 2020. The acquired business contributed revenues for $186.7 million, mainly assigned to Tubes segment, with a minor contribution to the Company’s margin for the period starting January 2, 2020 and ending December 31, 2020.

Fair value of net assets acquired

The application of the purchase method requires certain estimates and assumptions, mainly concerning the determination of the fair values of the acquired intangible assets and property, plant and equipment as well as the liabilities assumed at the date of the acquisition, including the timing and amounts of cash flow projections, the revenue growth rates, the customer attrition rates and the discount rate. The fair values determined at the acquisition date are based mainly on discounted cash flows and other valuation techniques.

The purchase price allocation was carried out with the assistance of a third-party expert. Following IFRS 3, during the period ended December 31, 2020, the Company continued reviewing the allocation and, based on new information related to events or circumstances existing at the acquisition date, made certain adjustments over the value of the identifiable assets acquired such as inventory, property, plant and equipment, other liabilities and deferred tax assets.

The allocation of the fair values determined for the assets and liabilities arising from the acquisition is as follows:

Fair value of acquired assets and liabilities:	$ million
Property, Plant and Equipment	503
Intangible assets	170
Working capital	138
Cash and Cash Equivalents	4
Borrowings	(53	)
Provisions	(27	)
Other assets and liabilities, net	(63	)
Net assets acquired	672

Tenaris acquired total assets and liabilities shown above, for approximately $1,029 million. As a result of the acquisition, Tenaris recognized goodwill for approximately $357 million. The goodwill is not deductible for tax purposes.

The goodwill generated by the acquisition is mainly attributable to the synergy created following the integration between Tenaris and IPSCO, which is expected to enhance Tenaris’s position as well as its local manufacturing presence in the U.S. market, and also expand its product range and services capabilities.

After the conclusion of the preliminary purchase price allocation determination and as a consequence of the unprecedented decline in oil prices and other changes in circumstances, the goodwill mentioned above was impaired, for more information see note 5.

Acquisition-related costs of $9.7 million were included in general and administrative expenses ($9.4 and $0.3 in 2019 and 2020 respectively). For contingent liabilities related to the acquisition see note 26 (i).

Acquisition of Saudi Steel Pipe Company

Acquisition and price determination

On January 21, 2019, Tenaris acquired 47.79% of the shares of SSPC, a welded steel pipes producer listed on the Saudi stock market, for a total amount of SAR530 million (approximately $141 million). The amount was paid with Tenaris cash in hand. SSPC’s facilities are located in the Eastern Province of the Kingdom of Saudi Arabia and have a manufacturing capacity of 360,000 tons per year. SSP started its operations in 1980 and serves energy industrial and commercial segments, is qualified to supply products with major national oil companies in the region.

Upon closing of the acquisition, four Tenaris’s nominees were appointed as new members of the SSPC’s board of directors and a Tenaris senior executive was appointed as managing director and chief executive officer of SSPC. Such appointment was ratified at the shareholders meeting of SSPC held on May 7, 2019, where the shareholders also approved the reappointment of the Tenaris’s nominees until June 6, 2022.

The Company has begun consolidating SSPC’s balances and results of operations as from January 21, 2019.

Fair value of net assets acquired

The application of the purchase method requires certain estimates and assumptions specially concerning the determination of the fair values of the acquired intangible assets and property, plant and equipment as well as the liabilities assumed at the date of the acquisition. The fair values determined at the acquisition date are based mainly on discounted cash flows and other valuation techniques.

The allocation of the fair values determined for the assets and liabilities arising from the acquisition is as follows:

Fair value of acquired assets and liabilities:	SAR million			$ million
Property, Plant and Equipment		671			179
Customer relationship		305			81
Investment in associated		77			21
Working capital		167			45
Cash and Cash Equivalents		32			9
Other Receivables		11			3
Borrowings		(304	)		(81	)
Employees end of service benefits		(59	)		(16	)
Deferred Tax Liabilities		(47	)		(13	)
Net assets acquired		853			228

Tenaris acquired 47.79% of total assets and liabilities shown above, approximately $109 million. As of the result of the acquisition, the Company recognized a Goodwill of approximately $32.9 million. Tenaris has chosen to recognize the non-controlling interest at the proportionate share of the acquiree’s net identifiable assets.

The acquired business contributed revenues for $170.6 million with a minor contribution to Tenaris’s margin for the period starting January 21, 2019 and ending December 31, 2019.

If the acquisition had occurred on January 1, 2019, consolidated revenue and profit after tax would have not changed significantly.

The purchase price allocation has been done with the assistance of a third party expert.

Note 33 - Agreement to Build a Welded Pipe Plant in West Siberia	12 Months Ended
	Dec. 31, 2020
Welded pipe plant in West Siberia [member]
Disclosure of joint ventures [line items]
Note 33 - Agreement to Build a Welded Pipe Plant in West Siberia	33 Agreement to build a welded pipe plant in West Siberia In 2019, Tenaris entered into an agreement with Severstal to build a welded pipe plant to produce OCTG products in the Surgut area, West Siberia, Russian Federation. Tenaris holds a 49% interest in the company, while Severstal owns the remaining 51%. The plant, which is estimated to require a total investment of $280 million is planned to have an annual production capacity of 300,000 tons. During 2019, we invested $19.6 million in the project. In 2020, the parties completed all the engineering to get the construction permit but on-site activities faced some delays due to the COVID-19 pandemic. Therefore, no additional contributions were made during 2020. In March 2021, the joint venture parties put on hold the construction activities, while they assess the impact of the changes in the relevant markets and competitive environment and determine whether any adjustments or changes to the project could be necessary.

Note 34 - Agreement to build a steel pipe premium connection threading plant in Baotou	12 Months Ended
	Dec. 31, 2020
Steel Pipe Premium Connection Threading Plant in Baotou [Member]
Disclosure of joint ventures [line items]
Note 34 - Agreement to build a steel pipe premium connection threading plant in Baotou	34 Agreement to build a steel pipe premium connection threading plant in Baotou In 2020, Tenaris entered into an agreement with Inner Mongolia Baotou Steel Union Co. Ltd. to build a steel pipe premium connection threading plant to produce OCTG products in Baotou, China. Under the agreement, Tenaris owns 60% of shares in the new company, while Inner Mongolia Baotou Steel Union Co. Ltd. holds the remaining 40%. The Company began consolidating balances and results of operations in December 2020. The plant, which is estimated to require a total investment of $32.6 million,and a 1-year construction period, is planned to have an annual production capacity of 70 thousand tons. During 2020, the Company contributed $2.3 million to the project.

Note 35 - Closure of facilities at JFE's Keihin steel complex	12 Months Ended
	Dec. 31, 2020
JFE [member] \| NKKTUBES [member]
Disclosure of information about unconsolidated structured entities controlled by investment entity [line items]
Note 35 - Closure of facilities at JFE’s Keihin steel complex	35 Closure of facilities at JFE’s Keihin steel complex Tenaris’s seamless pipe manufacturing facility in Asia, operated by NKKTubes, is located in Kawasaki, Japan, in the Keihin steel complex owned by JFE Holdings Inc. (“JFE”). Steel bars and other essential inputs and services for NKKTubes are supplied under a long-term agreement by JFE, which retains a 49% interest in NKKTubes. On March 27, 2020, JFE informed Tenaris of its decision to permanently cease as from JFE’s fiscal year ending March 2024 the operations of certain of its steel manufacturing facilities and other facilities located at the Keihin complex. The closure of JFE’s Keihin facilities may result in the unavailability of steel bars and other essential inputs or services used in NKKTubes’ manufacturing process, thereby affecting its operations. Tenaris and JFE have agreed to engage in discussions to seek mutually acceptable solutions.

Note 36 - Closure of Prudential Steel LTD	12 Months Ended
Note 36 - Closure of Prudential Steel LTD	Dec. 31, 2020
Prudential Steel Limited [Member]
Disclosure of information about unconsolidated structured entities controlled by investment entity [line items]
Note 36 - Closure of Prudential Steel LTD	36 Closure of Prudential Steel LTD Tenaris’s facility of Prudential Steel LTD, located in Calgary, Alberta, has been closed down and the pipe manufacturing operations of seamless, welded and premium products in Canada will be consolidated at Algoma Tubes Inc. in Sault Ste. Marie, Ontario with an additional investment of $72 million. This repositioning of the industrial activities, which will be completed by November 2021, will strengthen the competitiveness and increase the domestic production capabilities for the Canadian market.

Note 37 - Cancellation of title deed in Saudi Steel Pipe Company	12 Months Ended
	Dec. 31, 2020
Disclosure of Cancellation of title Deed in Affiliates [Abstract]
Note 37 - Cancellation of title deed in Saudi Steel Pipe Company	37 Cancellation of title deed in Saudi Steel Pipe Company The Company has recently learned through the Ministry of Justice’s online portal that the electronic title deeds to certain land plots of its Saudi Arabian subsidiary SSPC had become inactive due to cancellation by court order. The affected land plots, with a total surface of 811,284 square meters, are located in Dammam and were purchased from a private entity on February 13, 2010, pursuant to a written purchase agreement duly executed by SSPC in full compliance with the laws of the Kingdom of Saudi Arabia. The purchase of the land occurred before Tenaris’s acquisition of a 47.79% interest in SSPC in 2019. The affected plots are not part of the production facility of SSPC, have been partially used as a warehouse, and have a carrying value on Tenaris’s financial statements of $56.2 million. As of the date hereof, neither the cancellation nor the court order have been notified to SSPC or otherwise been made public, and the legal basis for the court order is unknown. SSPC is currently assessing the effects of the court order and the available alternatives to protect the land and reinstate the title deeds. At this time, it is not possible to predict the outcome of this matter.

Note 38 - Nationalization of Venezuelan Subsidiaries	12 Months Ended
Note 38 - Nationalization of Venezuelan Subsidiaries	Dec. 31, 2020
Disclosure of Nationalization of Subsidiaries [Abstract]
Note 38 - Nationalization of Venezuelan Subsidiaries	38 Nationalization of Venezuelan Subsidiaries In May 2009, within the framework of Decree Law 6058, Venezuela’s President announced the nationalization of, among other companies, the Company's majority-owned subsidiaries TAVSA - Tubos de Acero de Venezuela S.A. (“Tavsa”) and, Matesi Materiales Siderúrgicos S.A (“Matesi”), and Complejo Siderúrgico de Guayana, C.A (“Comsigua”), in which the Company has a non-controlling interest (collectively, the “Venezuelan Companies”). Tenaris and its wholly-owned subsidiary, Talta - Trading e Marketing Sociedad Unipessoal Lda (“Talta”), initiated arbitration proceedings against Venezuela before the ICSID in Washington D.C. in connection with these nationalizations. Matesi On January 29, 2016, the tribunal released its award on the arbitration proceeding concerning the nationalization of Matesi. The award upheld Tenaris’s and Talta’s claim that Venezuela had expropriated their investments in Matesi in violation of Venezuelan law as well as the bilateral investment treaties entered into by Venezuela with the Belgium-Luxembourg Economic Union and Portugal. The award granted compensation in the amount of $87.3 million for the breaches and ordered Venezuela to pay an additional amount of $85.5 million in pre-award interest, aggregating to a total award of $172.8 million, payable in full and net of any applicable Venezuelan tax, duty or charge. The tribunal granted Venezuela a grace period of six months from the date of the award to make payment in full of the amount due without incurring post-award interest, and resolved that if no, or no full, payment is made by then, post-award interest will apply at the rate of 9% per annum compounded at six-monthly rests from the date of the award until payment in full. As of December 31, 2020, post-award interest amounted to approximately $83.4 million. On March 14, 2016, Venezuela requested the rectification of the award pursuant to article 49(2) of the ICSID Convention and ICSID Arbitration Rule 49. The tribunal denied Venezuela’s request on June 24, 2016, ordering Venezuela to reimburse Tenaris and Talta for their costs incurred in connection with the rectification proceedings. On September 21, 2016, Venezuela submitted a request for annulment of the award as well as the stay of enforcement of the award in accordance with the ICSID Convention and Arbitration Rules. On March 24, 2017, an ad hoc committee constituted to decide on Venezuela´s requests rendered its decision to lift the stay of enforcement of the award. On August 8, 2018, the ad hoc committee rejected Venezuela’s application to annul the award. On June 8, 2018, Tenaris and Talta filed an action in federal court in the District of Columbia to recognize and enforce the award. Tenaris and Talta effected service on Venezuela in accordance with US law, and Venezuela failed to file an answer in the proceeding. Tenaris and Talta then moved for default judgment. Venezuela subsequently appeared in the proceedings but did not oppose the entry of default judgment on the award. On July 17, 2020, the Court entered judgment recognizing the Matesi award. The judgment orders Venezuela to pay to Tenaris and Talta an amount of $256.2 million, including principal and post-award interest through the judgment date, and provides for post-judgment interest to accrue on this sum at the U.S. federal statutory rate. The judgment, however, may not be enforced in the U.S. to the extent prohibited by the Venezuelan sanctions regulations issued by the U.S. Treasury Department’s Office of Foreign Assets Control. Tavsa and Comsigua On December 12, 2016, the tribunal issued its award upholding Tenaris’s and Talta’s claim that Venezuela had expropriated their investments in Tavsa and Comsigua in violation of the bilateral investment treaties entered into by Venezuela with the Belgium-Luxembourg Economic Union and Portugal. The award granted compensation in the amount of $137.0 million and ordered Venezuela to reimburse Tenaris and Talta $3.3 million in legal fees and ICSID administrative costs. In addition, Venezuela was ordered to pay interest from April 30, 2008 until the day of effective payment at a rate equivalent to LIBOR + 4% per annum, which as of December 31, 2020 amounted to approximately $132.4 million. On April 11, 2017, Venezuela submitted a request for annulment of the award as well as the stay of enforcement of the award in accordance with the ICSID Convention and Arbitration Rules. On February 23, 2018, an ad hoc committee constituted to decide on Venezuela’s requests rendered its decision to lift the stay of enforcement of the award. On December 28, 2018, the ad hoc committee rejected Venezuela’s application to annul the award. On June 8, 2018, Tenaris and Talta filed an action in federal court in the District of Columbia to recognize and enforce the award. Tenaris and Talta effected service on Venezuela in accordance with US law, and Venezuela failed to file an answer in the proceeding. Tenaris and Talta then moved for default judgment. Venezuela subsequently appeared in the proceedings but did not oppose the entry of default judgment on the award. It is expected that the Tavsa award will also be converted into a judgment. The judgment, however, may not be enforced in the U.S. to the extent prohibited by the Venezuelan sanctions regulations issued by the U.S. Treasury Department’s Office of Foreign Assets Control. As of December 31, 2020, Tenaris or its subsidiaries have net receivables related to its interest in the Venezuelan Companies for a total amount of approximately $48.7 million. See note III.B.

Note 39 - The COVID-19 pandemic and the oil & gas crisis and their impact on Tenaris's operations and financial condition	12 Months Ended
	Dec. 31, 2020
Extraordinary and Unusual Items 1 [Abstract]
Note 39 - The COVID-19 pandemic and the oil & gas crisis and their impact on Tenaris’s operations and financial condition	39 The COVID-19 pandemic and the oil & gas crisis and their impact on Tenaris’s operations and financial condition A novel strain of coronavirus (“SARS-CoV-2”) surfaced in China in December 2019 and subsequently spread to the rest of the world in early 2020. In March 2020, the World Health Organization declared COVID-19, the disease caused by the SARS-CoV-2 virus, a global pandemic. In response to the COVID-19 outbreak, countries have taken different measures in relation to prevention and containment. For example, several countries introduced bans on business activities or locked down cities or countries, including countries where Tenaris has operations (such as Argentina, China, Colombia, Italy, Mexico, Saudi Arabia and the United States). The rapid expansion of the virus, the surfacing of new strains of the virus in several countries, and the measures taken to contain it have triggered a severe fall in global economic activity and precipitated a serious crisis in the energy sector. While the extent of the effects of COVID-19 on the global economy and oil demand were still unclear, in March 2020, the members of OPEC+ (OPEC plus other major oil producers including Russia) did not agree to extend their agreement to cut oil production and Saudi Arabia launched a wave of additional supply on the market triggering a collapse in oil prices below $30 per barrel. This exacerbated what soon became clear was an unprecedented situation of oversupply, caused primarily by the sudden and dramatic fall in oil consumption consequent to the measures taken to contain the spread of the virus around the world. Although OPEC+ subsequently reached an agreement to cut production by as much as 9.7 million barrels per day, the situation of acute oversupply continued, causing oil prices to hit record lows. By the end of trading on April 20, 2020, the West Texas Intermediate (“WTI”) forward price for delivery in May, which had to be closed out the following day, fell to a negative value for the first time in history, as oil storage facilities were completely committed, and producers were forced to pay buyers to take their barrels. Since then, the price of oil has been recovering and currently stands above the level of $55 per barrel, bolstered by the actions to cut production taken by OPEC+ and the recovery of oil demand, as the global economy, especially industrial production, recovers and COVID-19 vaccination programs begin. With consumption exceeding production excess oil inventories built up in the first half of 2020 are being gradually reduced. The worldwide demand of oil, which stood at 100 million barrels per day in December 2019, fell to around 75-80 million barrels per day in April 2020 before recovering to around 94 million barrels per day in December 2020. Drilling activity in the United States and Canada, where it was most affected, has begun to recover but remains well below the level it was prior to the pandemic, while, in the rest of the world, any recovery will take longer following the reductions in investment plans made by oil and gas companies in response to the pandemic. There remains considerable uncertainty about the future duration and extent of the pandemic with new and more contagious variants of the COVID-19 virus appearing and the effectiveness of vaccination programs still to be seen. Status of our operations Although restrictions imposed in connection with the COVID-19 pandemic have been lifted in some countries where Tenaris operates, it is currently not possible to predict whether such measures will be relaxed further, reinstated or made more stringent. In addition, Tenaris has adjusted production levels at its facilities, which are operating with reduced volumes in line with market demand, and may perform additional adjustments. In order to safeguard the health and safety of its employees, customers and suppliers, Tenaris has taken preventive measures, including remote working for the majority of professional employees, restricting onsite access to essential operational personnel, keeping personnel levels at a minimum, implementing a special operations protocol to ensure social distancing and providing medical assistance and supplies to onsite employees. As of the date of these Consolidated Financial Statements, remote work and other work arrangements have not materially adversely affected Tenaris’s ability to conduct operations. In addition, these alternative working arrangements have not adversely affected our financial reporting systems, internal control over financial reporting or disclosure controls and procedures. Risks associated with the COVID-19 pandemic and the oil & gas crisis The COVID-19 pandemic and the ongoing oil & gas crisis poses the following main risks and challenges to Tenaris: Global oil demand may fail to recover its former level or even decrease further in the future, driving down prices even more or keeping them at very low levels, which would exert downward pressure on sales and margins of oil and gas companies, leading to further reductions and even generalized suspension of drilling activities (in the U.S. or elsewhere) and, as a result, materially adversely affecting our sales and financial position. Tenaris or its employees, contractors, suppliers, customers and other business partners may be prevented from conducting certain business activities for a prolonged or indefinite period of time. In addition, employees in some or all of our facilities, or those of our contracts, suppliers, customers or other business partners, may refuse to work due to health concerns while the COVID-19 outbreak is ongoing, If that happens, the continuity of our future operations may be severely affected. A continuing spread of COVID-19 and new strains of the virus may affect the availability and price of raw materials, energy and other inputs used by Tenaris in its operations. Any such disruption or increased prices could adversely affect Tenaris’s profitability. Mitigating actions In order to mitigate the impact of expected lower sales, starting from the first quarter 2020, Tenaris implemented a worldwide rightsizing program and cost containment plan aimed at preserving its financial resources and overall liquidity position and maintaining the continuity of its operations. These actions included: adjusting the level of our operations and workforce around the world, including through the temporary closure of certain facilities or production lines; introducing efficiency and productivity improvements throughout Tenaris’s industrial system; downsizing our fixed cost structure, including through pay reductions for senior management and board members, as well as R&D expenses, for a total annual savings of approximately $230 million on a yearly basis; reducing capital expenditures by $157 million in comparison to 2019 levels; reducing working capital, especially inventories, in accordance with the expected levels of activity; and increasing our focus on managing customer credit conditions. As of the date of these Consolidated Financial Statements, these rightsizing initiatives are largely complete and the principal objectives have been achieved; some residual actions are still ongoing. As part of these liquidity preservation initiatives, on June 2, 2020, the Annual Shareholders Meeting approved that no further dividends be distributed in respect of fiscal year 2019 on top of the interim dividend of approximately $153 million already paid in November 2019. On November 4, 2020, the Company’s Board of Directors approved the payment of an interim dividend of $0.07 per share ($0.14 per ADS), or approximately $82.6 million, paid on November 25, 2020. As of the date of these Consolidated Financial Statements, our capital and financial resources, and overall liquidity position, have not been materially affected by this new scenario. Tenaris has in place non-committed credit facilities and management believes it has adequate access to the credit markets. In addition, Tenaris has a net cash position of approximately $1,085 ^[1] million as of the end of December 2020 and a manageable debt amortization schedule. Considering our financial position and the funds provided by operating activities, management believes that we have sufficient resources to satisfy our current working capital needs, service our debt and address short-term changes in business conditions. Considering the global situation, the Company has renegotiated and continues to renegotiate existing contractual obligations with its counterparties to adapt the commitments to the decrease in activity. Management does not expect to disclose or incur in any material COVID-19-related contingency, and it considers its allowance for doubtful accounts sufficient to cover risks that could arise from credits with customers in accordance with IFRS 9. ¹ Net cash / debt is calculated in the following manner: Net cash= Cash and cash equivalents + Other investments (Current and Non-Current) +/- Derivatives hedging borrowings and investments– Borrowings (Current and Non-Current).

Note 40 - Subsequent Events	12 Months Ended
Note 40 - Subsequent Events	Dec. 31, 2020
Disclosure of non-adjusting events after reporting period [abstract]
Note 40 - Subsequent Events	40 Subsequent event Annual Dividend Proposal Upon approval of the Company´s annual accounts in March 2021, the Board of Directors intends to propose, for the approval of the Annual General Shareholders' meeting to be held on May 3, 2021, the payment of an annual dividend of $0.21 per share ($0.42 per ADS), or approximately $248 million, which includes the interim dividend of $0.07 per share ($0.14 per ADS) or approximately $83 million, paid on November 25, 2020. If the annual dividend is approved by the shareholders, a dividend of $0.14 per share ($0.28 per ADS), or approximately $165 million will be paid on May 26, 2021, with an ex-dividend date of May 24, 2021. These Consolidated Financial Statements do not reflect this dividend payable.

II. Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2020

Disclosure of Significant Accounting Policies [Abstract]

Description of accounting policy for basis of presentation [text block]

A Basis of presentation

Whenever necessary, certain comparative amounts have been reclassified to conform to changes in presentation in the current year.

(1) Accounting pronouncements applicable as from January 1, 2020 and relevant for Tenaris

IFRS 16 “Leases”, “COVID-19 - Related Rent Concessions”

Other accounting pronouncements that became effective during 2020 have no material effect on the Company’s financial condition or results of operations.

Description of accounting policy for investment in associates and joint ventures [text block]

B Group accounting

(1) Subsidiaries and transactions with non-controlling interests

(2) Non-consolidated companies

(2) Non-consolidated companies (Cont.)

Ternium

Both the Company and Ternium are under the indirect common control of San Faustin S.A. (“San Faustin”);
Four out of eight members of Ternium’s Board of Directors (including Ternium’s Chairman) are also members of the Company’s Board of Directors;
Under the shareholders’ agreement by and between the Company and Techint Holdings S.à r.l, a wholly owned subsidiary of San Faustin and Ternium’s main shareholder, dated January 9, 2006, Techint Holdings S.à.r.l, is required to take actions within its power to cause (a) one of the members of Ternium’s Board of Directors to be nominated by the Company and (b) any director nominated by the Company to be only removed from Ternium’s Board of Directors pursuant to previous written instructions of the Company.

Usiminas

Techgen

Global Pipe Company

Description of accounting policy for segment reporting [text block]

C Segment information

The Company is organized in one major business segment, Tubes, which is also the reportable operating segment.

The use of direct cost methodology to calculate the inventories, while under IFRS it is at full cost, including absorption of production overheads and depreciations;
The use of costs based on previously internally defined cost estimates, while, under IFRS, costs are calculated at historical cost;
Other timing differences, if any.

Description of accounting policy for foreign currency translation [text block]

D Foreign currency translation

(1) Functional and presentation currency

IAS 21 (revised), “The effects of changes in foreign exchange rates” defines the functional currency as the currency of the primary economic environment in which an entity operates.

Sales are mainly negotiated, denominated and settled in U.S. dollars. If priced in a currency other than the U.S. dollar, the sales price may consider exposure to fluctuation in the exchange rate versus the U.S. dollar;
Prices of their critical raw materials and inputs are priced and / or settled in U.S. dollars;
Transaction and operational environment and the cash flow of these operations have the U.S. dollar as reference currency;
Significant level of integration of the local operations within Tenaris’s international global distribution network;
Net financial assets and liabilities are mainly received and maintained in U.S. dollars;
The exchange rate of certain legal currencies has long-been affected by recurring and severe economic crises.

(2) Transactions in currencies other than the functional currency

(3) Translation of financial information in currencies other than the functional currency

Goodwill and fair value adjustments arising from the acquisition of a foreign operation are treated as assets and liabilities of the foreign operation and translated at the closing rate.

Description of accounting policy for property, plant and equipment [text block]

E Property, plant and equipment

Cost may also include transfers from equity of any gains or losses on qualifying cash flow hedges of foreign currency purchases of property, plant and equipment.

	Land	No Depreciation
	Buildings and improvements	30-50 years
	Plant and production equipment	10-40 years
	Vehicles, furniture and fixtures, and other equipment	4 -10 years

Description of accounting policy for intangible assets and goodwill [text block]

F Intangible assets

(1) Goodwill

(2) Information systems projects

(3) Licenses, patents, trademarks and proprietary technology

Management’s re-estimation of assets useful lives, performed in accordance with IAS 38, did not materially affect amortization expenses for 2020, 2019 and 2018.

(4) Research and development

Capitalized costs were not material for the years 2020, 2019 and 2018.

(5) Customer relationships

Management’s re-estimation of assets useful lives, performed in accordance with IAS 38, did not materially affect amortization expenses for 2020 and 2019.

Description of accounting policy for leases [text block]

G Right-of-use assets and lease liabilities

Description of accounting policy for impairment of non-financial assets [text block]

H Impairment of non-financial assets

(a) first, to reduce the carrying amount of any goodwill allocated to the CGU; and

For purposes of calculating the fair value less costs of disposal, Tenaris uses the estimated value of future cash flows that a market participant could generate from the corresponding CGU.

Non-financial assets other than goodwill that suffered an impairment are reviewed for possible reversal at each reporting date. For more information on impairment charges see note 5.

Description of accounting policy for investments other than investments accounted for using equity method [text block]

I Other investments

Other investments consist primarily of investments in financial instruments and time deposits with a maturity of more than three months at the date of purchase.

Purchases and sales of financial investments are recognized as of their settlement date.

Description of accounting policy for measuring inventories [text block]

J Inventories

Description of accounting policy for trade and other receivables [text block]

K Trade and other receivables

Description of accounting policy for determining components of cash and cash equivalents [text block]

L Cash and cash equivalents

In the Consolidated Statement of Financial Position, bank overdrafts are included in Borrowings in current liabilities.

For the purposes of the Consolidated Statement of Cash Flows, Cash and cash equivalents includes overdrafts.

Description of accounting policy for issued capital [text block]

M Equity

(1) Equity components

The Consolidated Statement of Changes in Equity includes:

The value of share capital, legal reserve, share premium and other distributable reserves calculated in accordance with Luxembourg law;
The currency translation adjustment, other reserves, retained earnings and non-controlling interest calculated in accordance with IFRS.

(2) Share capital

(3) Dividends distribution by the Company to shareholders

Dividends may be paid by the Company to the extent that it has distributable retained earnings, calculated in accordance with Luxembourg law. See note 26 (iii).

Description of accounting policy for borrowings [text block]

N Borrowings

Description of accounting policy for income tax [text block]

O Current and deferred income tax

Description of accounting policy for employee benefits [text block]

P Employee benefits

(1) Short-term obligations

(2) Post employment benefits

(2) Post employment benefits (Cont.)

Tenaris sponsors funded and unfunded defined benefit pension plans in certain subsidiaries. The most significant are:

An unfunded defined benefit employee retirement plan for certain senior officers. The plan is designed to provide certain benefits to those officers (additional to those contemplated under applicable labor laws) in case of termination of the employment relationship due to certain specified events, including retirement. This unfunded plan provides defined benefits based on years of service and final average salary. As of December 31, 2020 the outstanding liability for this plan amounts to $36.9 million.

Employees’ service rescission indemnity: the cost of this obligation is charged to the Consolidated Income Statement over the expected service lives of employees. This provision is primarily related to the liability accrued for employees at Tenaris’s Italian subsidiary. As from January 1, 2007 as a consequence of a change in an Italian law, employees were entitled to make contributions to external funds, thus, Tenaris’s Italian subsidiary pays every year the required contribution to the funds with no further obligation. As a result, the plan changed from a defined benefit plan to a defined contribution plan effective from that date, but only limited to the contributions of 2007 onwards. As of December 31, 2020 the outstanding liability for this plan amounts to $17.3 million.

Funded retirement benefit plan held in the US for the benefit of some employees hired prior a certain date, frozen for the purposes of credited service as well as determination of final average pay for the retirement benefit calculation. Plan assets consist primarily of investments in equities and money market funds. Additionally, an unfunded postretirement health and life plan is present that offers limited medical and life insurance benefits to the retirees, frozen to new participants. As of December 31, 2020 the outstanding liability for these plans amounts to $13.6 million.

Funded retirement benefit plans held in Canada for salary and hourly employees hired prior to a certain date based on years of service and, in the case of salaried employees, final average salary. Plan assets consist primarily of investments in equities and money market funds. Both plans were replaced for defined contribution plans. Effective June 2016 the salary plan was frozen for the purposes of credited service as well as determination of final average pay. As of December 31, 2020 the outstanding liability for this plan amounts to $10.6 million.

(3) Other long term benefits

(4) Termination benefits

(5) Other compensation obligations

Employee entitlements to annual leave, long-service leave, sick leave and other bonuses and compensations obligations are accrued as earned.

Compensation to employees in the event of dismissal is charged to income in the year in which it becomes payable.

Description of accounting policy for provisions [text block]

Q Provisions

This note should be read in conjunction with note 26.

Description of accounting policy for trade and other payables [text block]

R Trade and other payables

Description of accounting policy for recognition of revenue [text block]

S Revenue recognition

Tenaris provides services related to goods sold, which represent a non-material portion of sales revenue and mainly include:

Pipe Management Services. This comprises mainly preparation of the pipes ready to be run, delivery to the customer, storage services and rig return.

Field Services. Comprises field technical support and running assistance.

Freights, the Company recognized the revenue on a pro rata bases considering the units delivered and time elapsed.

Field services, the revenue is recognized considering output methods, in particular surveys of service completion provided by the customer.

Other revenues earned by Tenaris are recognized on the following basis:

Interest income: on the effective yield basis.
Dividend income from investments in other companies: when Tenaris’s right to receive payment is established.
Construction contracts revenues is recognized in accordance with the stage of the project completion.

Description of accounting policy for expenses [text block]

T Cost of sales and other selling expenses

Cost of sales and other selling expenses are recognized in the Consolidated Income Statement on the accrual basis of accounting.

Commissions, freights and other selling expenses, including shipping and handling costs, are recorded in Selling, general and administrative expenses in the Consolidated Income Statement.

Description of accounting policy for earnings per share [text block]

U Earnings per share

Earnings per share are calculated by dividing the income attributable to owners of the parent by the daily weighted average number of common shares outstanding during the year.

There are no dilutive potential ordinary shares.

Description of accounting policy for financial instruments [text block]

V Financial instruments

The Company classifies its financial instruments according to the following measurement categories:

those to be measured subsequently at fair value (either through OCI or through profit or loss), and
those to be measured at amortised cost.

The classification depends on the Company’s business model for managing the financial assets and contractual terms of the cash flows.

Exchange gains and losses and impairments related to the financial assets are immediately recognized in the Consolidated Income Statement.

For equity instruments, these are subsequently measured at fair value.

Accounting for derivative financial instruments and hedging activities is included within the Section III, Financial Risk Management.

II. Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of Summary of Significant Accounting Policies [Abstract]

Disclosure of detailed information about the estimated useful lives of property, plant and equipment [text block]

	Land	No Depreciation
	Buildings and improvements	30-50 years
	Plant and production equipment	10-40 years
	Vehicles, furniture and fixtures, and other equipment	4 -10 years

III. Financial Risk Management (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of detailed information about financial instruments [abstract]

Disclosure of effect of changes in foreign exchange rates [text block]

All amounts Long / (Short) in thousands of U.S. dollars	As of December 31,
Currency Exposure / Functional currency	2020			2019
Argentine Peso / U.S. dollar		(39,561	)		(95,811	)
Euro / U.S. dollar		(291,362	)		(103,518	)
Saudi Arabian Riyal / U.S. dollar		(125,789	)		(107,582	)

Disclosure of financial instruments by type of interest rate [text block]

		As of December 31,
		2020			2019
	Amount in thousands of U.S. dollars		%	Amount in thousands of U.S. dollars		%
Fixed rate (*)		237,320	38%		768,002	93%
Variable rate		381,687	62%		54,150	7%
Total		619,007			822,152

Disclosure of fair value of financial instruments [text block]

	Carrying amount		Measurement Categories						At Fair Value
December 31, 2019	Carrying amount		Amortized Cost		FVOCI		FVPL		Level 1		Level 2		Level 3
Assets
Cash and cash equivalents		1,554,299		387,602		-		1,166,697		1,166,697		-		-
Other investments		210,376		65,874		144,502		-		134,990		9,512		-
Fixed income (time-deposit, zero coupon bonds, commercial papers)		65,874		65,874		-		-		-		-		-
Certificates of deposits		20,637		20,637		-		-		-		-		-
Commercial papers		4,993		4,993		-		-		-		-		-
Other notes		40,244		40,244		-		-		-		-		-
Bonds and other fixed income		144,502		-		144,502		-		134,990		9,512		-
U.S. government securities		10,211		-		10,211		-		10,211		-		-
Non - U.S. government securities		28,637		-		28,637		-		19,125		9,512		-
Corporates securities		105,654		-		105,654		-		105,654		-		-
Derivative financial instruments		19,929		-		-		19,929		-		19,929		-
Other Investments Non-current		24,934		-		18,012		6,922		18,012		-		6,922
Bonds and other fixed income		18,012		-		18,012		-		18,012		-		-
Other investments		6,922		-		-		6,922		-		-		6,922
Trade receivables		1,348,160		1,348,160		-		-		-		-		-
Receivables C and NC (*)		261,678		93,239		48,659		-		-		-		48,659
Other receivables		141,898		93,239		48,659		-		-		-		48,659
Other receivables (non-financial)		119,780		-		-		-		-		-		-
Total				1,894,875		211,173		1,193,548		1,319,699		29,441		55,581
Liabilities
Borrowings C and NC		822,152		822,152		-		-		-		-		-
Trade payables		555,887		555,887		-		-		-		-		-
Finance Lease Liabilities C and NC		230,167		230,167		-		-		-		-		-
Derivative financial instruments		1,814		-		-		1,814		-		1,814		-
Total				1,608,206		-		1,814		-		1,814		-

	Carrying Amount		Measurement Categories						At Fair Value
December 31, 2020	Carrying Amount		Amortized Cost		FVOCI		FVPL		Level 1		Level 2		Level 3
Assets
Cash and cash equivalents		584,681		486,498		-		98,183		98,183		-		-
Other investments		872,488		763,697		108,791		-		108,791		-		-
Fixed income (time-deposit, zero coupon bonds, commercial papers)		763,697		763,697		-		-		-		-		-
U.S. Sovereign Bills		97,982		97,982		-		-		-		-		-
Non - U.S. Sovereign Bills		14,586		14,586		-		-		-		-		-
Certificates of deposits		222,132		222,132		-		-		-		-		-
Commercial papers		268,737		268,737		-		-		-		-		-
Other notes		160,260		160,260		-		-		-		-		-
Bonds and other fixed income		108,791		-		108,791		-		108,791		-		-
Non - U.S. government securities		20,219		-		20,219		-		20,219		-		-
Corporates securities		88,572		-		88,572		-		88,572		-
Derivative financial instruments		11,449		-		-		11,449		-		11,449		-
Other Investments Non-current		247,082		-		239,422		7,660		239,422		-		7,660
Bonds and other fixed income		239,422		-		239,422		-		239,422		-		-
Other investments		7,660		-		-		7,660		-		-		7,660
Trade receivables		968,148		968,148		-		-		-		-		-
Receivables C and NC (*)		232,152		90,330		48,659		-				-		48,659
Other receivables		138,989		90,330		48,659		-		-		-		48,659
Other receivables (non-financial)		93,163		-		-		-		-		-		-
Total				2,308,673		396,872		117,292		446,396		11,449		56,319
Liabilities
Borrowings C and NC		619,007		619,007		-		-		-		-		-
Trade payables		462,105		462,105		-		-		-		-		-
Finance Lease Liabilities C and NC		257,343		257,343		-		-		-		-		-
Derivative financial instruments		3,217		-		-		3,217		-		3,217		-
Total				1,338,455		-		3,217		-		3,217		-

Disclosure of fair value measurement [text block]

	Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
At the beginning of the year		55,581			52,985
(Decrease) / Addition		(3,604	)		2,933
Increase due to business combinations		3,915			-
Currency translation adjustment and others		427			(337	)
At the end of the year		56,319			55,581

Note 1 - Segment Information (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of operating segments [abstract]

Disclosure of operating segments [text block]

Year ended December 31, 2020	Tubes			Other			Total
IFRS - Net Sales		4,844			303			5,147
Management view - operating (loss)		(277	)		(50	)		(327	)
Differences in cost of sales		(138	)		4			(134	)
Differences in depreciation and amortization		1			(1	)		-
Differences in selling, general and administrative expenses		(2	)		-			(2	)
Differences in other operating income (expenses), net		(200	)		-			(200	)
IFRS - operating (loss)		(616	)		(47	)		(663	)
Financial income (expense), net								(65	)
(Loss) before equity in earnings of non-consolidated companies and income tax								(728	)
Equity in earnings of non-consolidated companies								109
(Loss) before income tax								(619	)
Capital expenditures		189			4			193
Depreciation and amortization		661			18			679

Year ended December 31, 2019	Tubes			Other		Total
IFRS - Net Sales		6,870			424		7,294
Management view - operating income		857			73		930
Differences in cost of sales		(105	)		3		(102)
Differences in depreciation and amortization		(1	)		-		(1	)
Differences in selling, general and administrative expenses		(1	)		1		-
Differences in other operating income (expenses), net		6			-		6
IFRS - operating income		756			77		833
Financial income (expense), net							19
Income before equity in earnings of non-consolidated companies and income tax							852
Equity in earnings of non-consolidated companies							82
Income before income tax							934
Capital expenditures		338			12		350
Depreciation and amortization		523			17		540

Year ended December 31, 2018	Tubes			Other		Total
IFRS - Net Sales		7,233			426		7,659
Management view - operating income		702			81		783
Differences in cost of sales		112			7		119
Differences in depreciation and amortization		(34	)		-		(34	)
Differences in selling, general and administrative expenses		(2	)		6		4
IFRS - operating income		778			94		872
Financial income (expense), net							37
Income before equity in earnings of non-consolidated companies and income tax							909
Equity in earnings of non-consolidated companies							194
Income before income tax							1,103
Capital expenditures		346			3		349
Depreciation and amortization		645			19		664

Disclosure of geographical areas [text block]

(all amounts in thousands of U.S. dollars)	North America	South America	Europe	Middle East & Africa	Asia Pacific	Unallocated (*)	Total
Year ended December 31, 2020
Net sales	2,179,949	776,235	642,793	1,227,532	320,225	-	5,146,734
Total assets	8,071,574	1,868,458	1,461,738	804,559	552,508	957,352	13,716,189
Trade receivables	411,692	115,972	139,427	210,194	90,863	-	968,148
Property, plant and equipment, net	3,971,101	1,050,619	823,057	242,939	105,465	-	6,193,181
Capital expenditures	71,531	63,111	39,691	10,452	8,537	-	193,322
Depreciation and amortization	408,546	106,827	84,518	44,259	34,656	-	678,806

Year ended December 31, 2019
Net sales	3,429,911	1,391,288	738,880	1,382,172	351,804	-	7,294,055
Total assets	7,885,120	2,227,044	2,282,775	958,424	609,663	879,965	14,842,991
Trade receivables	612,809	176,173	149,321	319,406	90,451	-	1,348,160
Property, plant and equipment, net	3,771,570	1,129,260	816,721	254,858	117,608	-	6,090,017
Capital expenditures	169,390	113,999	55,169	4,578	7,038	-	350,174
Depreciation and amortization	276,046	105,308	82,400	42,520	33,247	-	539,521

Year ended December 31, 2018
Net sales	3,611,509	1,462,044	724,733	1,559,988	300,314	-	7,658,588
Total assets	7,971,311	2,489,522	1,913,589	588,746	482,563	805,568	14,251,299
Trade receivables	791,190	280,801	215,202	383,358	66,815	-	1,737,366
Property, plant and equipment, net	3,859,060	1,133,113	848,178	94,040	129,517	-	6,063,908
Capital expenditures	196,220	68,603	77,467	2,047	5,136	-	349,473
Depreciation and amortization	441,705	108,558	82,769	10,389	20,936	-	664,357

Segment revenues by market [text block]

Revenues Tubes (in millions of U.S. dollars)	2020	2019	2018
Oil and Gas	4,073	5,757	6,042
Hydrocarbon Processing and Power Generation	371	534	602
Industrial and Other	400	579	589
Total	4,844	6,870	7,233

Note 2 - Cost of Sales (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of Cost of Sales [Abstract]

Disclosure of detailed information about cost of sales [text block]

	Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019			2018

Inventories at the beginning of the year		2,265,880			2,524,341			2,368,304
Increase in inventory due to business combinations		199,589			52,966			-
Plus: Charges of the year
Raw materials, energy, consumables and other		1,545,688			2,709,629			3,400,396
Services and fees		154,976			222,415			275,130
Labor cost (*)		757,359			870,261			855,040
Depreciation of property, plant and equipment		503,725			428,791			432,497
Amortization of intangible assets		8,121			5,948			8,220
Depreciation of right-of-use assets		40,127			28,727			-
Maintenance expenses		107,764			284,758			185,782
Allowance for obsolescence		35,809			29,138			25,457
Taxes		45,162			100,738			133,308
Other		59,790			115,663			119,507
		3,458,110			4,849,034			5,435,337
Less: Inventories at the end of the year		(1,636,673	)		(2,265,880	)		(2,524,341	)
		4,087,317			5,107,495			5,279,300

Note 3 - Selling, General and Administrative Expenses (Tables)

12 Months Ended

Dec. 31, 2020

Selling, general and administrative expense [abstract]

Disclosure of detailed information about selling, general and administrative expenses [text block]

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020		2019		2018

Services and fees		115,883		153,773		128,090
Labor cost (*)		444,436		481,854		470,928
Depreciation of property, plant and equipment		26,814		18,524		16,968
Amortization of intangible assets		82,355		41,967		206,672
Depreciation of right-of-use assets		17,664		15,564		-
Commissions, freight and other selling expenses		310,815		441,442		491,555
Provisions for contingencies		11,957		28,565		23,498
Allowances for doubtful accounts		4,644		(16,256)		1,751
Taxes		63,234		110,876		71,110
Other		41,425		89,665		99,404
		1,119,227		1,365,974		1,509,976

Note 4 - Labor costs (included in Cost of sales and in Selling, general and administrative expenses) (Tables)

12 Months Ended

Dec. 31, 2020

4. Labor costs (included in Cost of sales and in Selling, general and administrative expenses)

Disclosure of detailed information about labor costs [text block]

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019		2018

Wages, salaries and social security costs		1,036,211			1,274,474		1,250,783
Severance indemnities		142,458			24,637		25,225
Defined contribution plans		12,442			12,663		13,217
Pension benefits - defined benefit plans		11,097			18,207		15,390
Employee retention and long term incentive program		(413	)		22,134		21,353
		1,201,795			1,352,115		1,325,968

Disclosure of information about employees [text block]

Country	2020		2019		2018
Mexico		4,501		5,370		5,595
Argentina		4,376		5,405		5,427
Italy		2,039		2,144		2,155
USA		1,596		2,255		2,382
Romania		1,552		1,815		1,852
Brazil		1,360		1,360		1,287
Colombia		746		1,040		1,082
Canada		561		772		1,030
Indonesia		521		616		554
Japan		399		400		399
Other		1,377		2,023		1,204
		19,028		23,200		22,967

Note 5 - Impairment charge (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of impairment loss and reversal of impairment loss [abstract]

Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [text block]

(all amounts in millions of U.S. dollars)	Assets before impairment	Impairment	Assets after impairment
OCTG - USA	544	225	319
IPSCO	1,169	357	812
Coiled Tubing	108	4	104
Rods - USA	73	36	37

Disclosure of Sensitivity Analysis for Additional Impairment to Changes in Key Assumptions [text block]

(all amounts in millions of U.S. dollars)	+100Bps Discount rate	-100Bps Growth rate	-5% Cash flows
OCTG - USA	(60)	(43)	(16)
IPSCO	(117)	(77)	(41)
Coiled Tubing	(12)	(6)	(5)
Rods - USA	(5)	(3)	(2)

Note 6 - Other operating income and expenses (Tables)

12 Months Ended

Dec. 31, 2020

Note 5 - Other Operating Income and Expenses

Disclosure of detailed information about other operating income and expenses [text block]

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020		2019		2018

Other operating income
Net income from other sales		9,891		8,651		3,604
Net rents		5,501		5,089		4,909
Other		18,001		8,025		6,546
Recovery on allowance for doubtful receivables		-		1,239		-
		33,393		23,004		15,059

Other operating expenses
Contributions to welfare projects and non-profit organizations		12,989		11,199		11,379
Allowance for doubtful receivables		1,263		-		1,179
		14,252		11,199		12,558

Note 7 - Financial Results (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of Financial Results [Abstract]

Disclosure of detailed information about financial income (cost) [text block]

(all amounts in thousands of U.S. dollars)	Year ended December 31,
	2020			2019			2018

Interest Income		21,625			48,061			42,244
Net result on changes in FV of financial assets at FVPL		-			(64	)		(2,388	)
Impairment result on financial assets at FVTOCI		(3,238	)		-			-
Finance income (*)		18,387			47,997			39,856
Finance cost		(27,014	)		(43,381	)		(36,942	)
Net foreign exchange transactions results (**)		(74,422	)		27,868			28,845
Foreign exchange derivatives contracts results (***)		19,644			(11,616	)		6,576
Other		(1,590	)		(1,585	)		(1,035	)
Other financial results		(56,368	)		14,667			34,386
Net financial results		(64,995	)		19,283			37,300

Note 8 - Income Tax (Tables)

12 Months Ended

Dec. 31, 2020

Major components of tax expense (income) [abstract]

Disclosure of detailed information about income tax expense (benefit) [text block]

	Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019			2018

Current tax		(121,048	)		(299,692	)		(343,104	)
Deferred tax		97,898			97,240			113,897
Tax charge		(23,150	)		(202,452	)		(229,207	)

Disclosure of difference between income before tax and the theoretical amount that would arise using tax rate in each country [text block]

	Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019			2018

(Loss) Income before income tax		(619,267	)		933,710			1,103,107
Less Impairment charges (non deductible)		622,402			-			-
Income before income tax without impairment charges		3,135			933,710			1,103,107


Tax calculated at the tax rate in each country		21,052			(186,752	)		(207,422	)
Effect of currency translation on tax base		(72,936	)		(53,296	)		(77,552	)
Changes in the tax rates		(958	)		13			(1,824	)
Utilization of previously unrecognized tax losses		98			547			-
Tax revaluation, withholding tax and others		29,594			37,036			57,591
Tax charges		(23,150	)		(202,452	)		(229,207	)

Note 10 - Property, Plant and Equipment, Net (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of detailed information about property, plant and equipment [abstract]

Disclosure of detailed information about property, plant and equipment [text block]

Year ended December 31, 2020	Land and civil buildings		Industrial buildings, plant and production equipment		Vehicles, furniture and fixtures		Work in progress		Spare parts and equipment		Total

Cost
Values at the beginning of the year		799,139		12,468,813		399,724		108,308		60,602		13,836,586
Currency translation adjustment		(545)		72,650		443		(2,095)		(162)		70,291
Increase due to business combinations (*)		39,622		440,366		7,195		16,255		-		503,438
Additions		1,451		1,524		620		157,315		6,845		167,755
Transfers / Reclassifications		5,881		157,473		15,586		(176,589)		-		2,351
Disposals / Consumptions		(5,964)		(61,281)		(8,811)		(968)		(5,392)		(82,416)
Values at the end of the year		839,584		13,079,545		414,757		102,226		61,893		14,498,005

Depreciation and impairment
Accumulated at the beginning of the year		121,468		7,302,135		322,966		-		-		7,746,569
Currency translation adjustment		(288)		56,560		405		-		-		56,677
Depreciation charge		11,368		492,973		26,198		-		-		530,539
Impairment charge (See note 5)		-		36,000		-		-		-		36,000
Transfers / Reclassifications		(1)		349		(475)		-		-		(127)
Disposals / Consumptions		(89)		(57,897)		(6,848)		-		-		(64,834)
Accumulated at the end of the year		132,458		7,830,120		342,246		-		-		8,304,824
At December 31, 2020		707,126		5,249,425		72,511		102,226		61,893		6,193,181

Note 11 - Intangible Assets, Net (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of detailed information about intangible assets [abstract]

Disclosure of reconciliation of changes in intangible assets and goodwill [text block]

Year ended December 31, 2019	Information system projects			Licenses, patents and trademarks (*)			Goodwill			Customer relationships		Total
Cost
Values at the beginning of the year		580,622			464,571			2,085,936			2,058,859		5,189,988
Currency translation adjustment		(1,917	)		(70	)		(968	)		-		(2,955	)
Increase due to business combinations (***)		405			-			32,869			81,192		114,466
Additions		35,487			772			-			-		36,259
Transfers / Reclassifications		(4,665	)		-			-			-		(4,665	)
Disposals		(5,062	)		(1,531	)		-			-		(6,593	)
Values at the end of the year		604,870			463,742			2,117,837			2,140,051		5,326,500

Amortization and impairment
Accumulated at the beginning of the year		513,984			373,466			797,592			2,038,981		3,724,023
Currency translation adjustment		(1,734	)		-			-			-		(1,734	)
Amortization charge		28,937			719			-			18,259		47,915
Disposals		(4,850	)		(413	)		-			-		(5,263	)
Accumulated at the end of the year		536,337			373,772			797,592			2,057,240		3,764,941
At December 31, 2019		68,533			89,970			1,320,245			82,811		1,561,559

Year ended December 31, 2020	Information system projects			Licenses, patents and trademarks (*)			Goodwill			Customer relationships		Total

Cost
Values at the beginning of the year		604,870			463,742			2,117,837			2,140,051		5,326,500
Currency translation adjustment		1,108			220			(5,058	)		-		(3,730	)
Increase due to business combinations (**)		11,563			87,000			357,183			71,100		526,846
Additions		24,965			602			-			-		25,567
Transfers / Reclassifications		(1,393	)		-			-			-		(1,393	)
Disposals		(3,761	)		(1,064	)		-			-		(4,825	)
Values at the end of the year		637,352			550,500			2,469,962			2,211,151		5,868,965

Amortization and impairment
Accumulated at the beginning of the year		536,337			373,772			797,592			2,057,240		3,764,941
Currency translation adjustment		890			(1	)		-			-		889
Amortization charge		42,931			8,760			-			38,785		90,476
Impairment charge (See note 5)		-			-			586,402			-		586,402
Transfers / Reclassifications		931			-			-			-		931
Disposals		(3,730	)		-			-			-		(3,730	)
Accumulated at the end of the year		577,359			382,531			1,383,994			2,096,025		4,439,909
At December 31, 2020		59,993			167,969			1,085,968			115,126		1,429,056

Disclosure of information for cash-generating units [text block]

(all amounts in millions of U.S. dollars)
	Tubes Segment
CGU	Hydril Acquisition		Other		Total
Tamsa (Hydril and other)		346		19		365
Siderca (Hydril and other)		265		93		358
Hydril		309		-		309
Other		-		54		54
Total		920		166		1,086

Note 12 - Right-of-use Assets, Net and Lease Liabilities (Tables)

12 Months Ended

Dec. 31, 2020

Presentation of leases for lessee [abstract]

Disclosure of quantitative information about right-of-use assets [text block]

Year ended December 31, 2020	Land and Civil Buildings			Industrial Buildings, Plant and Production Equipment			Vehicles, furniture and fixtures			Total
Cost
Opening net book amount		36,137			225,389			14,194			275,720
Currency translation adjustment		(839	)		746			530			437
Increase due to business combinations (*)		3,461			13,730			7,556			24,747
Additions		11,534			42,573			5,034			59,141
Transfers / Reclassifications		439			(458	)		136			117
Disposals		(8,800	)		(8,622	)		(8,835	)		(26,257	)
At December 31, 2020		41,932			273,358			18,615			333,905


Depreciation
Accumulated at the beginning of the year		8,330			30,581			3,683			42,594
Currency translation adjustment		(92	)		145			190			243
Depreciation charge		13,200			37,671			6,920			57,791
Transfers / Reclassifications		(2,876	)		1,702			1,291			117
Disposals		(3,420	)		(2,106	)		(3,267	)		(8,793	)
Accumulated at the end of the year		15,142			67,993			8,817			91,952
At December 31, 2020		26,790			205,365			9,798			241,953

Year ended December 31, 2019	Land and Civil Buildings			Industrial Buildings, Plant and Production Equipment			Vehicles, furniture and fixtures			Total
Cost
Opening net book amount		27,713			202,352			8,335			238,400
Currency translation adjustment		(88	)		6			8			(74	)
Increase due to business combinations (**)		229			2,038			-			2,267
Additions		9,292			24,985			7,165			41,442
Transfers / Reclassifications		-			496			(496	)		-
Disposals		(1,009	)		(4,488	)		(818	)		(6,315	)
At December 31, 2019		36,137			225,389			14,194			275,720


Depreciation
Accumulated at the beginning of the year		-			-			-			-
Currency translation adjustment		(3	)		3			8			8
Depreciation charge		8,514			31,869			3,908			44,291
Transfers / Reclassifications		-			(62	)		62			-
Disposals		(181	)		(1,229	)		(295	)		(1,705	)
Accumulated at the end of the year		8,330			30,581			3,683			42,594
At December 31, 2019		27,807			194,808			10,511			233,126

Lease liability evolution [text block]

	Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019

Opening net book amount		230,167			234,149
Increase due to business combinations		26,046			2,267
Translation differences		7,656			2,690
Additions		58,536			36,957
Cancellations		(17,529	)		(4,688	)
Repayments (*)		(51,666	)		(43,974	)
Interest accrued		4,133			2,766
At December 31,		257,343			230,167

Note 13 - Investments in Non-consolidated Companies (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of unconsolidated structured entities [abstract]

Disclosure of unconsolidated structured entities [text block]

	Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
At the beginning of the year		879,965			805,568
Translation differences		(31,977	)		(10,781	)
Equity in earnings of non-consolidated companies		108,799			82,036
Increase due to business combinations		-			20,635
Dividends and distributions declared (*)		(861	)		(28,037	)
Additions		-			19,610
Increase / (decrease) in equity reserves and others		1,426			(9,066	)
At the end of the year		957,352			879,965

Disclosure of detailed information about principal non-consolidated companies [text block]

		% ownership at December 31,		Value at December 31,
Company	Country of incorporation	2020	2019	2020	2019
a) Ternium (*)	Luxembourg	11.46%	11.46%	830,028	751,105
b) Usiminas (**)	Brazil	3.07%	3.07%	65,144	74,593
c) Techgen	Mexico	22.00%	22.00%	19,536	9,888
d) Global Pipe Company	Saudi Arabia	35.00%	35.00%	23,421	22,550
Others	-	-	-	19,223	21,829
				957,352	879,965

Disclosure of detailed information about selected financial information [text block]

(all amounts in thousands of U.S. dollars)	Ternium
	2020	2019
Non-current assets	8,289,460	8,757,320
Current assets	4,566,775	4,178,213
Total assets	12,856,235	12,935,533
Non-current liabilities	2,559,485	3,452,535
Current liabilities	1,853,597	1,768,125
Total liabilities	4,413,082	5,220,660

Equity	8,443,153	7,714,873

Revenues	8,735,435	10,192,818
Gross profit	1,635,512	1,740,378
Net income for the year attributable to owners of the parent	778,468	564,269
Total comprehensive income for the year, net of tax, attributable to owners of the parent	666,667	445,473

(all amounts in thousands of U.S. dollars)	Usiminas
	2020	2019
Non-current assets	3,487,317	4,335,662
Current assets	2,276,368	2,198,449
Total assets	5,763,685	6,534,111
Non-current liabilities	1,661,605	1,955,395
Current liabilities	861,912	716,930
Total liabilities	2,523,517	2,672,325

Equity	3,240,168	3,861,786

Revenues	3,132,949	3,790,206
Gross profit	624,199	478,141
Net income for the year attributable to owners of the parent	106,361	52,779

Note 14 - Receivables - Non Current (Tables)

12 Months Ended

Dec. 31, 2020

Trade and other non-current receivables [abstract]

Disclosure of detailed information about non-current receivables [text block]

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020		2019
Employee advances and loans		4,563		6,008
Tax credits		18,046		20,065
Receivables from related parties		62,790		59,999
Legal deposits		8,600		12,378
Advances to suppliers and other advances		4,803		3,772
Receivable Venezuelan subsidiaries		48,659		48,659
Others		6,842		6,222
		154,303		157,103

Note 15 - Inventories, Net (Tables)

12 Months Ended

Dec. 31, 2020

Classes of current inventories [abstract]

Disclosure of detailed information about inventories [text block]

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
Finished goods		691,922			968,329
Goods in process		417,097			612,888
Raw materials		143,558			221,954
Supplies		488,802			486,411
Goods in transit		158,929			194,015
		1,900,308			2,483,597
Allowance for obsolescence, see note 24 (i)		(263,635	)		(217,717	)
		1,636,673			2,265,880

Note 16 - Receivables and Prepayments, Net (Tables)

12 Months Ended

Dec. 31, 2020

Current prepayments and current accrued income [abstract]

Disclosure of detailed information about receivables and prepayments [text block]

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
Prepaid expenses and other receivables		26,457			30,579
Government entities		3,075			1,867
Employee advances and loans		4,672			8,189
Advances to suppliers and other advances		14,661			17,180
Government tax refunds on exports		2,723			670
Receivables from related parties		16,217			19,837
Miscellaneous		13,961			31,145
		81,766			109,467
Allowance for other doubtful accounts, see note 24 (i)		(3,917	)		(4,892	)
		77,849			104,575

Note 17 - Current Tax Assets and Liabilities (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of Current Tax Receivables and Payables [Abstract]

Disclosure of detailed information about current tax assets [text block]

		Year ended December 31,
Current tax assets	2020		2019
V.A.T. credits		106,293		112,161
Prepaid taxes		30,091		55,227
		136,384		167,388

Disclosure of detailed information about tax liabilities [text block]

		Year ended December 31,
Current tax liabilities	2020		2019
Income tax liabilities		27,616		64,994
V.A.T. liabilities		9,933		9,953
Other taxes		53,044		52,678
		90,593		127,625

Note 18 - Trade Receivables, Net (Tables)

12 Months Ended

Dec. 31, 2020

Trade and other receivables [abstract]

Disclosure of detailed information about current trade receivables [text block]

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
Current accounts		1,017,663			1,387,494
Receivables from related parties		4,161			9,448
		1,021,824			1,396,942
Allowance for doubtful accounts, see note 24 (i)		(53,676	)		(48,782	)
		968,148			1,348,160

Disclosure if detailed information about the aging of trade receivables [text block]

(all amounts in thousands of U.S. dollars)	Trade Receivables			Not Due			Past due
	Trade Receivables			Not Due			1 - 180 days			> 180 days
At December 31, 2020
Guaranteed		191,514			170,796			18,778			1,940
Not guaranteed		830,310			655,132			116,802			58,376
Guaranteed and not guaranteed		1,021,824			825,928			135,580			60,316
Expected loss rate		0.07	%		0.04	%		0.23	%		0.72	%
Allowances for doubtful accounts		(721	)		(321	)		(331	)		(69	)
Nominative allowances for doubtful accounts		(52,955	)		(718	)		(1,011	)		(51,226	)
Net Value		968,148			824,889			134,238			9,021

(all amounts in thousands of U.S. dollars)	Trade Receivables			Not Due			Past due
	Trade Receivables			Not Due			1 - 180 days			> 180 days
At December 31, 2019
Guaranteed		234,427			205,764			26,899			1,764
Not guaranteed		1,162,515			948,449			157,960			56,106
Guaranteed and not guaranteed		1,396,942			1,154,213			184,859			57,870
Expected loss rate		0.09	%		0.04	%		0.24	%		0.57	%
Allowances for doubtful accounts		(1,294	)		(529	)		(455	)		(310	)
Nominative allowances for doubtful accounts		(47,488	)		-			(1,922	)		(45,566	)
Net Value		1,348,160			1,153,684			182,482			11,994

Note 19 - Cash and Cash Equivalents and Other Investments (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of Cash and Cash Equivalents and Other Investments [Abstract]

Detailed disclosure of cash and cash equivalents and other investments [text block]

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020		2019
Cash and cash equivalents
Cash at banks		117,807		118,314
Liquidity funds		98,183		1,166,697
Short – term investments		368,691		269,288
		584,681		1,554,299
Other investments - current
Fixed income (time-deposit, zero coupon bonds, commercial papers)		763,697		65,874
Bonds and other fixed income		108,791		144,502
		872,488		210,376
Other investments - Non-current
Bonds and other fixed income		239,422		18,012
Others		7,660		6,922
		247,082		24,934

Note 20 - Borrowings (Tables)

12 Months Ended

Dec. 31, 2020

Borrowings [abstract]

Disclosure of detailed information about borrowings [text block]

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
Non-current
Bank borrowings		315,884			40,896
Costs of issue of debt		(145	)		(16	)
		315,739			40,880
Current
Bank borrowings		303,170			781,258
Bank overdrafts		98			24
Costs of issue of debt		-			(10	)
		303,268			781,272
Total Borrowings		619,007			822,152

Disclosure of detailed information about the maturity of borrowings [text block]

	1 year or less		1 - 2 years		2 – 3 years		3 - 4 years		4 - 5 years		Over 5 years		Total
At December 31, 2020
Borrowings		303,268		104,147		207,595		3,997		-		-		619,007
Total borrowings		303,268		104,147		207,595		3,997		-		-		619,007

Interest to be accrued (*)		9,829		5,068		1,014		22		-		-		15,933
Total		313,097		109,215		208,609		4,019		-		-		634,940

	1 year or less		1 - 2 years		2 – 3 years		3 - 4 years		4 - 5 years		Over 5 years		Total
At December 31, 2019
Borrowings		781,272		17,307		23,573		-		-		-		822,152
Total borrowings		781,272		17,307		23,573		-		-		-		822,152

Interest to be accrued (*)		11,370		1,045		117		-		-		-		12,532
Total		792,642		18,352		23,690		-		-		-		834,684

Disclosure of detailed information about significant borrowings [text block]

			In million of U.S. dollars
Disbursement date	Borrower	Type	Original & Outstanding	Final maturity
2020	Maverick	Bilateral	50	2021
2020	Maverick	Bilateral	75	2022
2020	Tamsa	Bilateral	60	2023
2020	Tamsa	Bilateral	80	2023
2020	Tamsa	Bilateral	60	2023
2020	SSPC	Multiple Banks	81	2021 - 2024

Disclosure of detailed information about weighted average interest rates of borrowings [text block]

		2020				2019
Total borrowings			2.51	%			3.18	%

Disclosure of detailed information about borrowings by currency and rate [text block]

(all amounts in thousands of U.S. dollars)			Year ended December 31,
Currency	Interest rates	2020		2019
USD	Variable		274,600		-
USD	Fixed		17,936		18,370
SAR	Fixed		20,902		16,106
EUR	Fixed		1,828		5,108
EUR	Variable		473		1,296
Total non-current borrowings			315,739		40,880

(all amounts in thousands of U.S. dollars)			Year ended December 31,
Currency	Interest rates	2020		2019
USD	Variable		67,823		17,092
USD	Fixed		2,322		274,799
EUR	Variable		1,015		80
EUR	Fixed		3,886		3,772
MXN	Fixed		147,997		424,964
ARS	Fixed		3,699		86
SAR	Variable		37,776		35,666
SAR	Fixed		38,750		24,797
Others	Variable		-		16
Total current borrowings			303,268		781,272

Disclosure of borrowings evolution [text block]

		Year ended December 31, 2020
(all amounts in thousands of U.S. dollars)	Non current			Current
At the beginning of the year		40,880			781,272
Translation differences		266			(487	)
Proceeds and repayments, net		234,455			(478,913	)
Interests accrued less payments		426			(12,016	)
Reclassifications		(12,940	)		12,940
Increase due to business combinations		52,652			398
Overdrafts variation		-			74
At the end of the year		315,739			303,268

Note 21 - Deferred Income Tax (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of temporary difference, unused tax losses and unused tax credits [abstract]

Disclosure of deferred tax assets and liabilities [text block]

(all amounts in thousands of U.S. dollars)	Fixed assets			Inventories			Intangible and Other			Total
At the beginning of the year		651,339			19,396			118,062			788,797
Translation differences		1,644			-			253			1,897
Increase due to business combinations		89,306			-			43,397			132,703
Charged to other comprehensive income		-			-			(1,194	)		(1,194	)
Income statement (credit)		(39,874	)		(4,141	)		(34,725	)		(78,740	)
At December 31, 2020		702,415			15,255			125,793			843,463

(all amounts in thousands of U.S. dollars)	Fixed assets			Inventories			Intangible and Other			Total
At the beginning of the year		710,995			25,048			46,532			782,575
Translation differences		(347	)		-			(4	)		(351	)
Increase due to business combinations		5,621			-			11,209			16,830
Charged to other comprehensive income		-			-			423			423
Income statement charge / (credit)		(64,930	)		(5,652	)		59,902			(10,680	)
At December 31, 2019		651,339			19,396			118,062			788,797

(all amounts in thousands of U.S. dollars)	Provisions and allowances			Inventories			Tax losses			Other			Total
At the beginning of the year		(19,653	)		(93,404	)		(382,832	)		(181,606	)		(677,495	)
Translation differences		1,804			513			1,996			644			4,957
Increase due to business combinations		(7,452	)		(24,580	)		(33,598	)		(34,974	)		(100,604	)
Charged to other comprehensive income		-			-			-			(1,952	)		(1,952	)
Income statement charge / (credit)		4,093			31,534			(65,715	)		10,930			(19,158	)
At December 31, 2020		(21,208	)		(85,937	)		(480,149	)		(206,958	)		(794,252	)

(all amounts in thousands of U.S. dollars)	Provisions and allowances			Inventories			Tax losses			Other			Total
At the beginning of the year		(16,116	)		(86,585	)		(396,257	)		(86,184	)		(585,142	)
Translation differences		362			306			497			286			1,451
Increase due to business combinations		(1,160	)		(1,413	)		(1,172	)		(2,238	)		(5,983	)
Charged to other comprehensive income		-			-			-			(1,261	)		(1,261	)
Income statement charge / (credit)		(2,739	)		(5,712	)		14,100			(92,209	)		(86,560	)
At December 31, 2019		(19,653	)		(93,404	)		(382,832	)		(181,606	)		(677,495	)

Disclosure of temporary difference, unused tax losses and unused tax credits [text block]

(all amounts in thousands of U.S. dollars)		Year ended December 31,
	2020			2019
Deferred tax assets to be recovered after 12 months		(640,603	)		(538,274	)
Deferred tax liabilities to be settled after 12 months		840,892			766,852

Deferred tax [text block]

(all amounts in thousands of U.S. dollars)		Year ended December 31,
	2020			2019
Deferred tax assets		(205,590	)		(225,680	)
Deferred tax liabilities		254,801			336,982
		49,211			111,302

		Year ended December 31,
	2020			2019
At the beginning of the year		111,302			197,433
Translation differences		6,854			1,100
Increase due to business combinations		32,099			10,847
Charged to other comprehensive income		(3,146	)		(838	)
Income statement (credit)		(97,898	)		(97,240	)
At the end of the year		49,211			111,302

Note 22 - Other Liabilities (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of Other Liabilities [Abstract]

Disclosure of other non-current liabilities [text block]

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020		2019
Post-employment benefits		136,811		144,993
Other-long term benefits		64,928		85,473
Miscellaneous		43,896		20,917
		245,635		251,383

Disclosure of net defined benefit liability (asset) [text block]

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020		2019
Unfunded		115,774		125,573
Funded		21,037		19,420
		136,811		144,993

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
Values at the beginning of the year		125,573			97,318
Current service cost		4,796			7,978
Interest cost		6,496			5,526
Curtailments and settlements		(1,237	)		-
Remeasurements (*)		(2,230	)		7,010
Translation differences		(415	)		(1,567	)
Increase due to business combinations		1,566			15,660
Benefits paid from the plan		(22,955	)		(9,328	)
Other		4,180			2,976
At the end of the year		115,774			125,573

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
Present value of funded obligations		176,309			160,412
Fair value of plan assets		(157,335	)		(145,160	)
Liability (*)		18,974			15,252

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
At the beginning of the year		160,412			146,885
Translation differences		2,148			4,542
Current service cost		850			721
Interest cost		5,009			5,754
Remeasurements (*)		18,025			12,769
Benefits paid		(9,266	)		(10,259	)
Other		(869	)		-
At the end of the year		176,309			160,412

Disclosure of sensitivity analysis for actuarial assumptions [text block]

	Year ended December 31,
	2020	2019
Discount rate	1% - 7%	1% - 7%
Rate of compensation increase	0% - 3%	0% - 3%

	Year ended December 31,
	2020	2019
Discount rate	1 % - 3 %	3 % - 4 %
Rate of compensation increase	0 % - 3 %	0 % - 3 %

Disclosure of fair value of plan assets [text block]

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020			2019
At the beginning of the year		(145,160	)		(132,438	)
Translation differences		(1,729	)		(4,137	)
Return on plan assets		(4,411	)		(5,018	)
Remeasurements		(10,396	)		(10,507	)
Contributions paid to the plan		(5,017	)		(3,589	)
Benefits paid from the plan		9,266			10,259
Other		112			270
At the end of the year		(157,335	)		(145,160	)

		Year ended December 31,
	2020			2019
Equity instruments		49.3	%		49.0	%
Debt instruments		46.8	%		47.0	%
Others		3.9	%		4.0	%

Disclosure of other current liabilities [text block]

		Year ended December 31,
(all amounts in thousands of U.S. dollars)	2020		2019
Payroll and social security payable		175,175		153,009
Miscellaneous		27,651		23,255
		202,826		176,264

Note 23 - Non-current allowances and provisions (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of Non-current allowances and provisions [Abstract]

Disclosure of detailed information about non-current allowances and provisions from liabilities [text block]

Liabilities

		Year ended December 31,
	2020			2019
(all amounts in thousands of U.S. dollars)
Values at the beginning of the year		54,599			36,089
Translation differences		(5,739	)		(1,571	)
Increase due to business combinations		26,542			-
Additional provisions		478			19,904
Reclassifications		557			5,641
Used		(3,219	)		(5,464	)
Values at the end of the year		73,218			54,599

Note 24 - Current allowances and provisions (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of Current allowances and provisions [Abstract]

Disclosure of detailed information about current allowances and provisions deducted from assets [text block]

(i) Deducted from assets

Year ended December 31, 2020	Allowance for doubtful accounts - Trade receivables			Allowance for other doubtful accounts - Other receivables			Allowance for inventory obsolescence
(all amounts in thousands of U.S. dollars)
Values at the beginning of the year		(48,782	)		(4,892	)		(217,717	)
Translation differences		(37	)		801			1,560
Increase due to business combinations		(1,930	)		-			(76,776	)
(Additional) allowances		(4,644	)		(1,263	)		(35,809	)
Used		1,717			1,437			65,107
At December 31, 2020		(53,676	)		(3,917	)		(263,635	)

Year ended December 31, 2019	Allowance for doubtful accounts - Trade receivables			Allowance for other doubtful accounts - Other receivables			Allowance for inventory obsolescence
(all amounts in thousands of U.S. dollars)
Values at the beginning of the year		(66,535	)		(6,784	)		(209,796	)
Translation differences		9			88			794
Increase due to business combinations		(1,788	)		-			(10,761	)
(Additional) / reversals allowances		16,256			1,239			(29,138	)
Used		3,276			565			31,184
At December 31, 2019		(48,782	)		(4,892	)		(217,717	)

Disclosure of detailed information about current allowances and provisions from liabilities [text block]

(ii) Liabilities

Year ended December 31, 2020	Sales risks			Other claims and contingencies (*)			Total
(all amounts in thousands of U.S. dollars)
Values at the beginning of the year		5,867			11,150			17,017
Translation differences		(5	)		(975	)		(980	)
Increase due to business combinations		116			398			514
Additional provisions		9,728			1,751			11,479
Reclassifications		-			(557	)		(557	)
Used		(13,911	)		(1,283	)		(15,194	)
At December 31, 2020		1,795			10,484			12,279

Year ended December 31, 2019	Sales risks			Other claims and contingencies (*)			Total
(all amounts in thousands of U.S. dollars)
Values at the beginning of the year		6,814			17,469			24,283
Translation differences		(28	)		(570	)		(598	)
Increase due to business combinations		505			8,000			8,505
Additional / (reversals) provisions		11,880			(3,219	)		8,661
Reclassifications		-			(5,641	)		(5,641	)
Used		(13,304	)		(4,889	)		(18,193	)
At December 31, 2019		5,867			11,150			17,017

Note 25 - Derivative Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of detailed information about financial instruments [abstract]

Disclosure of detailed information about derivative financial instruments [text block]

(all amounts in thousands of U.S. dollars)		Year ended December 31,
	2020			2019
Derivatives hedging borrowings and investments		10,119			19,000
Other Derivatives		1,330			929
Contracts with positive fair values		11,449			19,929

Derivatives hedging borrowings and investments		(2,250	)		-
Other Derivatives		(967	)		(1,814	)
Contracts with negative fair values		(3,217	)		(1,814	)
Total		8,232			18,115

Disclosure of detailed information about hedged items [text block]

(all amounts in thousands of U.S. dollars)				Fair Value						Hedge Accounting Reserve
Purchase currency	Sell currency	Term	2020			2019			2020			2019
MXN	USD	2021		9,838			18,999			156			404
USD	MXN	2021		(5	)		(576	)		-			-
USD	EUR	2021		(1,969	)		-			5			-
EUR	USD	2021		543			588			-			-
JPY	USD	2021		-			(190	)		-			-
USD	BRL	2021		412			(234	)		85			-
JPY	USD	2030		94			-			(4,958	)		2,149
USD	KWD	2021		(246	)		103			(59	)		38
USD	CAD	2021		-			(200	)		-			-
USD	COP	2021		-			(345	)		-			-
USD	CNY	2021		(482	)		(167	)		-			-
Others		2021		47			137			-			-
Total				8,232			18,115			(4,771	)		2,591

Disclosure of detailed information of the hedge reserve evolution [text block]

	Equity Reserve Dec-18			Movements 2019		Equity Reserve Dec-19		Movements 2020			Equity Reserve Dec-20
Foreign Exchange		(916	)		3,507		2,591		(7,362	)		(4,771	)
Total Cash flow Hedge		(916	)		3,507		2,591		(7,362	)		(4,771	)

Note 28 - Cash Flow Disclosures (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of Cash Flow [Abstract]

Disclosure of detailed information about cash flow disclosures [text block]

			Year ended December 31,
(i)	Changes in working capital	2020			2019			2018
	Inventories		828,796			311,459			(176,443	)
	Receivables and prepayments and current tax assets		74,877			(34,368	)		30,144
	Trade receivables		409,163			428,326			(517,579	)
	Other liabilities		(34,871	)		(18,295	)		(22,984	)
	Customer advances		(34,388	)		16,844			5,976
	Trade payables		(184,442	)		(180,857	)		(57,066	)
			1,059,135			523,109			(737,952	)
(ii)	Income tax accruals less payments
	Tax accrued		23,150			202,452			229,207
	Taxes paid		(140,364	)		(395,869	)		(170,713	)
			(117,214	)		(193,417	)		58,494
(iii)	Interest accruals less payments, net
	Interest accrued		8,627			(4,616	)		(2,914	)
	Interest received		19,613			30,890			40,613
	Interest paid		(28,778	)		(30,655	)		(31,548	)
			(538	)		(4,381	)		6,151

Note 29 - Related Party Transactions (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of transactions between related parties [abstract]

Disclosure of transactions between related parties [text block]

	(all amounts in thousands of U.S. dollars)		Year ended December 31,
		2020		2019		2018
(i)	Transactions
	(a) Sales of goods and services
	Sales of goods to non-consolidated parties		20,183		20,577		23,709
	Sales of goods to other related parties		18,243		69,972		131,548
	Sales of services to non-consolidated parties		5,829		5,620		7,641
	Sales of services to other related parties		5,049		4,386		5,647
			49,304		100,555		168,545
	(b) Purchases of goods and services
	Purchases of goods to non-consolidated parties		84,485		174,588		245,186
	Purchases of goods to other related parties		12,892		51,765		106,624
	Purchases of services to non-consolidated parties		6,979		9,404		9,556
	Purchases of services to other related parties		18,133		54,514		46,179
			122,489		290,271		407,545

	(all amounts in thousands of U.S. dollars)		At December 31,
		2020			2019
(ii)	Period-end balances
	(a) Arising from sales / purchases of goods / services
	Receivables from non-consolidated parties		78,721			78,884
	Receivables from other related parties		4,447			10,400
	Payables to non-consolidated parties		(24,914	)		(19,100	)
	Payables to other related parties		(2,310	)		(7,048	)
			55,944			63,136
	(b) Financial debt
	Finance lease liabilities from non-consolidated parties		(2,042	)		(2,064	)
	Finance lease liabilities from other related parties		(810	)		-
			(2,852	)		(2,064	)

Note 30 - Fees Paid to the Company's Principal Accountant (Tables)

12 Months Ended

Dec. 31, 2020

Auditor's remuneration [abstract]

Disclosure of auditors' remuneration [text block]

(all amounts in thousands of U.S. dollars)		Year ended December 31,
	2020		2019		2018
Audit fees		3,781		3,846		3,841
Audit-related fees		134		50		43
Tax fees		102		7		-
All other fees		-		1		7
Total		4,017		3,904		3,891

Note 32 - Business Combinations (Tables)

12 Months Ended

Dec. 31, 2020

Ipsco Tubulars Inc [Member]

Disclosure of detailed information about business combination [line items]

Disclosure of detailed information about business combination [text block]

Fair value of acquired assets and liabilities:	$ million
Property, Plant and Equipment	503
Intangible assets	170
Working capital	138
Cash and Cash Equivalents	4
Borrowings	(53	)
Provisions	(27	)
Other assets and liabilities, net	(63	)
Net assets acquired	672

Saudi Steel Pipe Company [member]

Disclosure of detailed information about business combination [line items]

Disclosure of detailed information about business combination [text block]

Fair value of acquired assets and liabilities:	SAR million			$ million
Property, Plant and Equipment		671			179
Customer relationship		305			81
Investment in associated		77			21
Working capital		167			45
Cash and Cash Equivalents		32			9
Other Receivables		11			3
Borrowings		(304	)		(81	)
Employees end of service benefits		(59	)		(16	)
Deferred Tax Liabilities		(47	)		(13	)
Net assets acquired		853			228

Principal Subsidiaries (Tables)

12 Months Ended

Dec. 31, 2020

Principal subsidiaries

Principal subsidiaries

Company	Country of Incorporation	Main activity	Percentage of ownership at December 31, (*)
Company	Country of Incorporation	Main activity	2020	2019	2018
ALGOMA TUBES INC.	Canada	Manufacturing of seamless steel pipes	100%	100%	100%
CONFAB INDUSTRIAL S.A. and subsidiaries	Brazil	Manufacturing of welded steel pipes and capital goods	100%	100%	100%
DALMINE S.p.A.	Italy	Manufacturing of seamless steel pipes	100%	100%	100%
HYDRIL COMPANY and subsidiaries (except detailed) (a)	USA	Manufacture and marketing of premium connections	100%	100%	100%
IPSCO TUBULARS INC. and subsidiaries	USA	Manufacturing of welded and seamless steel pipes	100%	NA	NA
KAZAKHSTAN PIPE THREADERS LIMITED LIABILITY PARTNERSHIP	Kazakhstan	Threading of premium products	100%	100%	100%
MAVERICK TUBE CORPORATION and subsidiaries	USA	Manufacturing of welded steel pipes	100%	100%	100%
NKKTUBES	Japan	Manufacturing of seamless steel pipes	51%	51%	51%
P.T. SEAMLESS PIPE INDONESIA JAYA	Indonesia	Manufacturing of seamless steel products	89%	89%	89%
PRUDENTIAL STEEL LTD. (b)	Canada	Manufacturing of welded steel pipes	100%	100%	100%
S.C. SILCOTUB S.A.	Romania	Manufacturing of seamless steel pipes	100%	100%	100%
SAUDI STEEL PIPE CO.	Saudi Arabia	Manufacturing of welded steel pipes	48%	48%	NA
SIAT SOCIEDAD ANONIMA	Argentina	Manufacturing of welded and seamless steel pipes	100%	100%	100%
SIDERCA SOCIEDAD ANONIMA INDUSTRIAL Y COMERCIAL and subsidiaries	Argentina	Manufacturing of seamless steel pipes	100%	100%	100%
TALTA - TRADING E MARKETING SOCIEDADE UNIPESSOAL LDA.	Portugal	Holding Company	100%	100%	100%
TENARIS BAY CITY, INC.	USA	Manufacturing of seamless steel pipes	100%	100%	100%
TENARIS CONNECTIONS BV	Netherlands	Development, management and licensing of intellectual property	100%	100%	100%
TENARIS FINANCIAL SERVICES S.A.	Uruguay	Financial company	100%	100%	100%
TENARIS GLOBAL SERVICES (CANADA) INC.	Canada	Marketing of steel products	100%	100%	100%
TENARIS GLOBAL SERVICES (U.S.A.) CORPORATION	USA	Marketing of steel products	100%	100%	100%
TENARIS GLOBAL SERVICES (UK) LTD	United Kingdom	Holding company and marketing of steel products	100%	100%	100%
TENARIS GLOBAL SERVICES S.A. and subsidiaries (except detailed) (c)	Uruguay	Holding company and marketing of steel products	100%	100%	100%
TENARIS INVESTMENTS (NL) B.V. and subsidiaries	Netherlands	Holding company	100%	100%	NA
TENARIS INVESTMENTS S.àr.l.	Luxembourg	Holding company	100%	100%	100%
TENARIS TUBOCARIBE LTDA.	Colombia	Manufacturing of welded and seamless steel pipes	100%	100%	100%
TUBOS DE ACERO DE MEXICO, S.A.	Mexico	Manufacturing of seamless steel pipes	100%	100%	100%

II. Accounting Policies (Details Textual) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017
Disclosure of associates [line items]
Goodwill or intangible assets recognized in relation to investments in non consolidated companies under the equity method	$ 0
Impairment loss on equity method investment in non-consolidated companies	0	$ 0	$ 0
Additional Amortization Expenses	11,100
Total intangible assets and goodwill	1,429,056	1,561,559
Research and development expense	41,800	61,100	63,400
Selling, general and administrative expenses, amortization of intangible assets	$ 82,355	$ 41,967	$ 206,672
Number of shares authorised (in shares) \| shares	2,500,000,000	2,500,000,000	2,500,000,000
Par value per share (in dollars per share) \| $ / shares	$ 1.00	$ 1.00	$ 1.00
Total number of shares issued (in shares) \| shares	1,180,536,830	1,180,536,830	1,180,536,830
Number of shares outstanding at end of period (in shares) \| shares	1,180,536,830	1,180,536,830	1,180,536,830
Number of votes, per share	1	1	1
Net defined benefit liability (asset) at end of period	$ 82,400	$ 99,000
Employee benefits, unit vesting period (Year)	4 years
Employee benefits, company redemption period (Year)	7 years			10 years
Employee benefits, early redemption period (Year)				7 years
Carrying value of units granted	$ 108,700	119,900
ITALY
Disclosure of associates [line items]
Net defined contribution plan liability (asset) at end of period	17,300
UNITED STATES
Disclosure of associates [line items]
Net defined contribution plan liability (asset) at end of period	13,600
Unfunded defined benefit employee retirement plan for certain senior officers [member]
Disclosure of associates [line items]
Net defined benefit liability (asset) at end of period	36,900
Funded post-employment benefits [member]
Disclosure of associates [line items]
Net defined benefit liability (asset) at end of period	176,309	160,412	$ 146,885
Funded post-employment benefits [member] \| Canada [member]
Disclosure of associates [line items]
Net defined contribution plan liability (asset) at end of period	10,600
Information system projects [member]
Disclosure of associates [line items]
Total intangible assets and goodwill	59,993	68,533
Licenses, patents, trademarks, and proprietary technology [member]
Disclosure of associates [line items]
Total intangible assets and goodwill	86,700	86,700	$ 86,700
Customer-related intangible assets [member]
Disclosure of associates [line items]
Total intangible assets and goodwill	$ 115,126	$ 82,811
Customer-related intangible assets [member] \| Maverick acquisition [member]
Disclosure of associates [line items]
Finite-lived intangible asset, useful life (Year)	14 years
Remaining amortisation period of intangible assets material to entity (Year)			0 years	2 years
Selling, general and administrative expenses, amortization of intangible assets			$ 109
Customer-related intangible assets [member] \| Hydrill acquisition [member]
Disclosure of associates [line items]
Finite-lived intangible asset, useful life (Year)	10 years
Customer-related intangible assets [member] \| Saudi Steel Pipe Company [member]
Disclosure of associates [line items]
Finite-lived intangible asset, useful life (Year)	9 years
Finite-lived intangible asset, residual value	$ 63,800
Finite-lived intangible asset, residual useful life (Year)	7 years
Customer-related intangible assets [member] \| Ipsco Tubulars Inc [Member]
Disclosure of associates [line items]
Finite-lived intangible asset, useful life (Year)	3 years
Finite-lived intangible asset, residual value	$ 51,300
Finite-lived intangible asset, residual useful life (Year)	2 years
Top of range [member]
Disclosure of associates [line items]
Discount rate used in current estimate of value in use	13.60%
Top of range [member] \| Information system projects [member]
Disclosure of associates [line items]
Finite-lived intangible asset, useful life (Year)	3 years
Top of range [member] \| Licenses, patents, trademarks, and proprietary technology [member]
Disclosure of associates [line items]
Finite-lived intangible asset, useful life (Year)	10 years
Bottom of range [member]
Disclosure of associates [line items]
Discount rate used in current estimate of value in use	8.00%
Global Pipe Company [Member]
Disclosure of associates [line items]
Number of Board Members	5
Global Pipe Company [Member] \| Saudi Steel Pipe Company [member]
Disclosure of associates [line items]
Proportion of ownership interest in joint venture	35.00%
Number of Board Members Can be Appointed Through Shareholders Agreement	1
Usiminas [member] \| The new SHA [member]
Disclosure of associates [line items]
Shares bound to SHA (in shares) \| shares	483,600,000
Percent of company voting capital	68.60%
T/T Group [member] \| The new SHA [member]
Disclosure of associates [line items]
Percent of company voting capital	47.10%
Ternium entitites [member] \| The new SHA [member]
Disclosure of associates [line items]
Percent of company voting capital	39.50%
Confab [member] \| The new SHA [member]
Disclosure of associates [line items]
Percent of company voting capital	7.60%
NSSMC [member] \| The new SHA [member]
Disclosure of associates [line items]
Percent of company voting capital	45.90%
Previdencia Usiminas [member] \| The new SHA [member]
Disclosure of associates [line items]
Percent of company voting capital	7.00%
Ternium S.A. [member] \| Techgen s.a. [member]
Disclosure of associates [line items]
Proportion of ownership interest in joint venture	48.00%
Tecpetrol International S.A. [member] \| Techgen s.a. [member]
Disclosure of associates [line items]
Proportion of ownership interest in joint venture	30.00%
Tenaris [member] \| Techgen s.a. [member]
Disclosure of associates [line items]
Proportion of ownership interest in joint venture	22.00%
Ternium S.A. [member]
Disclosure of associates [line items]
Proportion of ownership interest in associate	11.46%
Usiminas [member] \| CONFAB INDUSTRIAL S.A. and subsidiaries [member]
Disclosure of associates [line items]
Proportion of voting rights held in associate	5.19%	5.19%
Usiminas [member] \| Ternium S.A. [member]
Disclosure of associates [line items]
Proportion of ownership interest in associate	5.19%
Proportion of voting rights held in associate	3.07%
Usiminas [member] \| Ternium S.A. [member] \| Preference shares [member]
Disclosure of associates [line items]
Number of shares subscribed to (in shares) \| shares	1,300,000
Usiminas [member] \| Ternium S.A. [member] \| Ordinary shares [member]
Disclosure of associates [line items]
Number of shares subscribed to (in shares) \| shares	36,500,000

II. Accounting Policies - Estimated Useful Lives of Property, Plant and Equipment (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)
Disclosure of detailed information about property, plant and equipment [line items]
Additional depreciation expenses	$ 45
Buildings and improvements [member] \| Bottom of range [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment (Year)	30 years
Buildings and improvements [member] \| Top of range [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment (Year)	50 years
Plant and production equipment [member] \| Bottom of range [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment (Year)	10 years
Plant and production equipment [member] \| Top of range [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment (Year)	40 years
Vehicles, furniture and fixtures, and other equipment [member] \| Bottom of range [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment (Year)	4 years
Vehicles, furniture and fixtures, and other equipment [member] \| Top of range [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment (Year)	10 years

III. Financial Risk Management (Details Textual)
$ in Thousands

12 Months Ended

Dec. 31, 2020

USD ($)

Dec. 31, 2019

USD ($)

Dec. 31, 2018

USD ($)

Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]

Debt to equity ratio

0.05

0.06

Reserve of exchange differences on translation

$ 2,300

$ 600

Gain (loss) on interest rate risk if market interest rates were higher

619,007

822,152

$ (7,100)

$ (7,700)

Concentration Risk, percentage

88.00%

96.00%

Liquid financial assets, percentage

$ 968,148

$ 1,348,160

$ 1,737,366

12.00%

Financial liabilities, fair value as a percentage of carrying value

100.00%

Reserve of cash flow hedges, continuing hedges

$ (4,800)

$ 2,600

UNITED STATES

Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]

Liquid financial assets, percentage denominated by a specific currency

95.00%

Allowance for doubtful accounts - trade receivables [member]

Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]

Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]

$ 53,700

$ 48,800

Past due [member]

Guarantees under credit insurance [member]

195,900

242,700

Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]

Letter of credit and other bank guarantees [member]

134,900

178,700

Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]

Other guarantees [member]

47,800

55,200

Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]

Financial guarantee contracts [member] | Past due [member]

8,800

600

Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]

Fixed interest rate [member]

20,700

28,700

Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]

Concentration Risk, percentage

^[1]

237,320

$ 768,002

Current borrowings

$ 197,000

^[1]

38.00%

93.00%

One percent change, Argentine Peso / U.S. dollar foreign exchange risk [member]

Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]

Reserve of exchange differences on translation

$ 400

$ 1,000

One percent change, Euro / U.S. dollar foreign exchange risk [member]

Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]

Foreign exchange risk, currency exposure

2,900

1,000

One percent change, Saudi Arabian Riyal / U.S. dollar foreign exchange risk [member]

Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]

Foreign exchange risk, currency exposure

5,100

4,600

One percent change, Saudi Arabian Riyal / U.S. dollar foreign exchange risk [member] | Foreign exchange derivatives contracts [member]

Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]

Foreign exchange risk, currency exposure

$ 1,000

$ 4,900

[1]	Out of the $237 million fixed rate borrowings, $197 million are short-term.

III. Financial Risk Management - Financial Assets and Liabilities Which Impact Profit and Loss (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Argentine Peso / U.S. dollar foreign exchange risk [member]
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]
Currency exposure / functional currency	$ (39,561)	$ (95,811)
Euro / U.S. dollar foreign exchange risk [member]
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]
Currency exposure / functional currency	(291,362)	(103,518)
Saudi Arabian Riyal / US Dollar exchange risk [member]
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]
Currency exposure / functional currency	$ (125,789)	$ (107,582)

III. Financial Risk Management - Proportions of Variable-rate and Fixed-rate Debt (Details) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2020

Dec. 31, 2019

Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]

Significant borrowings as of closing date

$ 619,007

$ 822,152

Percentage

88.00%

96.00%

Fixed interest rate [member]

Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]

Significant borrowings as of closing date

^[1]

$ 237,320

$ 768,002

Percentage

^[1]

38.00%

93.00%

Floating interest rate [member]

Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]

Significant borrowings as of closing date

$ 381,687

$ 54,150

Percentage

62.00%

7.00%

[1]	Out of the $237 million fixed rate borrowings, $197 million are short-term.

III. Financial Risk Management - Financial Instruments and Classification Within the Fair Value Hierarchy (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Assets
Cash and cash equivalents	$ 584,681	$ 1,554,299	$ 428,361
Other investments - current	872,488	210,376
Derivative financial instruments	11,449	19,929
Other investments - non-current	247,082	24,934
Current trade receivables	968,148	1,348,160	1,737,366
Other receivables	232,152	261,678
Liabilities
Borrowings C and NC	619,007	822,152
Trade payables	462,105	555,887
Finance Lease Liabilities C and NC	257,343	230,167	$ 234,149
Derivative financial instruments	3,217	1,814
Derivatives [member]
Assets
Derivative financial instruments	11,449	19,929
Other receivables [member]
Assets
Other receivables	138,989	141,898
Other receivables (non-Financial) [member]
Assets
Other receivables	93,163	119,780
Fixed Income (time-deposit, zero coupon bonds, commercial papers) [member]
Assets
Other investments - current	763,697	65,874
U.S. Sovereign Bills [Member]
Assets
Other investments - current	97,982
Non - U.S. Sovereign Bills [Member]
Assets
Other investments - current	14,586
Certificates of Deposits [member]
Assets
Other investments - current	222,132	20,637
Commercial Papers [member]
Assets
Other investments - current	268,737	4,993
Other notes [member]
Assets
Other investments - current	160,260	40,244
Bonds and other fixed income [member]
Assets
Other investments - current	108,791	144,502
Other investments - non-current	239,422	18,012
U.S. government securities [member]
Assets
Other investments - current		10,211
Non - U.S. government securities [member]
Assets
Other investments - current	20,219	28,637
Corporates securities [member]
Assets
Other investments - current	88,572	105,654
Other investments [member]
Assets
Other investments - non-current	7,660	6,922
Level 1 of fair value hierarchy [member]
Assets
Cash and cash equivalents	98,183	1,166,697
Other investments - current	108,791	134,990
Other investments - non-current	239,422	18,012
Current trade receivables
Other receivables
Total	446,396	1,319,699
Liabilities
Borrowings C and NC
Trade payables
Finance Lease Liabilities C and NC
Derivative financial instruments
Total
Level 1 of fair value hierarchy [member] \| Derivatives [member]
Assets
Derivative financial instruments
Level 1 of fair value hierarchy [member] \| Other receivables [member]
Assets
Other receivables
Level 1 of fair value hierarchy [member] \| Other receivables (non-Financial) [member]
Assets
Other receivables
Level 1 of fair value hierarchy [member] \| Fixed Income (time-deposit, zero coupon bonds, commercial papers) [member]
Assets
Other investments - current
Level 1 of fair value hierarchy [member] \| U.S. Sovereign Bills [Member]
Assets
Other investments - current
Level 1 of fair value hierarchy [member] \| Non - U.S. Sovereign Bills [Member]
Assets
Other investments - current
Level 1 of fair value hierarchy [member] \| Certificates of Deposits [member]
Assets
Other investments - current
Level 1 of fair value hierarchy [member] \| Commercial Papers [member]
Assets
Other investments - current
Level 1 of fair value hierarchy [member] \| Other notes [member]
Assets
Other investments - current
Level 1 of fair value hierarchy [member] \| Bonds and other fixed income [member]
Assets
Other investments - current	108,791	134,990
Other investments - non-current	239,422	18,012
Level 1 of fair value hierarchy [member] \| U.S. government securities [member]
Assets
Other investments - current		10,211
Level 1 of fair value hierarchy [member] \| Non - U.S. government securities [member]
Assets
Other investments - current	20,219	19,125
Level 1 of fair value hierarchy [member] \| Corporates securities [member]
Assets
Other investments - current	88,572	105,654
Level 1 of fair value hierarchy [member] \| Other investments [member]
Assets
Other investments - non-current
Level 2 of fair value hierarchy [member]
Assets
Cash and cash equivalents
Other investments - current		9,512
Other investments - non-current
Current trade receivables
Other receivables
Total	11,449	29,441
Liabilities
Borrowings C and NC
Trade payables
Finance Lease Liabilities C and NC
Derivative financial instruments	3,217	1,814
Total	3,217	1,814
Level 2 of fair value hierarchy [member] \| Derivatives [member]
Assets
Derivative financial instruments	11,449	19,929
Level 2 of fair value hierarchy [member] \| Other receivables [member]
Assets
Other receivables
Level 2 of fair value hierarchy [member] \| Other receivables (non-Financial) [member]
Assets
Other receivables
Level 2 of fair value hierarchy [member] \| Fixed Income (time-deposit, zero coupon bonds, commercial papers) [member]
Assets
Other investments - current
Level 2 of fair value hierarchy [member] \| U.S. Sovereign Bills [Member]
Assets
Other investments - current
Level 2 of fair value hierarchy [member] \| Non - U.S. Sovereign Bills [Member]
Assets
Other investments - current
Level 2 of fair value hierarchy [member] \| Certificates of Deposits [member]
Assets
Other investments - current
Level 2 of fair value hierarchy [member] \| Commercial Papers [member]
Assets
Other investments - current
Level 2 of fair value hierarchy [member] \| Other notes [member]
Assets
Other investments - current
Level 2 of fair value hierarchy [member] \| Bonds and other fixed income [member]
Assets
Other investments - current		9,512
Other investments - non-current
Level 2 of fair value hierarchy [member] \| U.S. government securities [member]
Assets
Other investments - current
Level 2 of fair value hierarchy [member] \| Non - U.S. government securities [member]
Assets
Other investments - current		9,512
Level 2 of fair value hierarchy [member] \| Corporates securities [member]
Assets
Other investments - current
Level 2 of fair value hierarchy [member] \| Other investments [member]
Assets
Other investments - non-current
Level 3 of fair value hierarchy [member]
Assets
Cash and cash equivalents
Other investments - current
Other investments - non-current	7,660	6,922
Current trade receivables
Other receivables	48,659	48,659
Total	56,319	55,581
Liabilities
Borrowings C and NC
Trade payables
Finance Lease Liabilities C and NC
Derivative financial instruments
Total
Level 3 of fair value hierarchy [member] \| Derivatives [member]
Assets
Derivative financial instruments
Level 3 of fair value hierarchy [member] \| Other receivables [member]
Assets
Other receivables	48,659	48,659
Level 3 of fair value hierarchy [member] \| Other receivables (non-Financial) [member]
Assets
Other receivables
Level 3 of fair value hierarchy [member] \| Fixed Income (time-deposit, zero coupon bonds, commercial papers) [member]
Assets
Other investments - current
Level 3 of fair value hierarchy [member] \| U.S. Sovereign Bills [Member]
Assets
Other investments - current
Level 3 of fair value hierarchy [member] \| Non - U.S. Sovereign Bills [Member]
Assets
Other investments - current
Level 3 of fair value hierarchy [member] \| Certificates of Deposits [member]
Assets
Other investments - current
Level 3 of fair value hierarchy [member] \| Commercial Papers [member]
Assets
Other investments - current
Level 3 of fair value hierarchy [member] \| Other notes [member]
Assets
Other investments - current
Level 3 of fair value hierarchy [member] \| Bonds and other fixed income [member]
Assets
Other investments - current
Other investments - non-current
Level 3 of fair value hierarchy [member] \| U.S. government securities [member]
Assets
Other investments - current
Level 3 of fair value hierarchy [member] \| Non - U.S. government securities [member]
Assets
Other investments - current
Level 3 of fair value hierarchy [member] \| Corporates securities [member]
Assets
Other investments - current
Level 3 of fair value hierarchy [member] \| Other investments [member]
Assets
Other investments - non-current	7,660	6,922
Financial assets at amortised cost, category [member]
Assets
Cash and cash equivalents	486,498	387,602
Other investments - current	763,697	65,874
Other investments - non-current
Current trade receivables	968,148	1,348,160
Other receivables	90,330	93,239
Total	2,308,673	1,894,875
Liabilities
Borrowings C and NC	619,007	822,152
Trade payables	462,105	555,887
Finance Lease Liabilities C and NC	257,343	230,167
Derivative financial instruments
Total	1,338,455	1,608,206
Financial assets at amortised cost, category [member] \| Derivatives [member]
Assets
Derivative financial instruments
Financial assets at amortised cost, category [member] \| Other receivables [member]
Assets
Other receivables	90,330	93,239
Financial assets at amortised cost, category [member] \| Other receivables (non-Financial) [member]
Assets
Other receivables
Financial assets at amortised cost, category [member] \| Fixed Income (time-deposit, zero coupon bonds, commercial papers) [member]
Assets
Other investments - current	763,697	65,874
Financial assets at amortised cost, category [member] \| U.S. Sovereign Bills [Member]
Assets
Other investments - current	97,982
Financial assets at amortised cost, category [member] \| Non - U.S. Sovereign Bills [Member]
Assets
Other investments - current	14,586
Financial assets at amortised cost, category [member] \| Certificates of Deposits [member]
Assets
Other investments - current	222,132	20,637
Financial assets at amortised cost, category [member] \| Commercial Papers [member]
Assets
Other investments - current	268,737	4,993
Financial assets at amortised cost, category [member] \| Other notes [member]
Assets
Other investments - current	160,260	40,244
Financial assets at amortised cost, category [member] \| Bonds and other fixed income [member]
Assets
Other investments - current
Other investments - non-current
Financial assets at amortised cost, category [member] \| U.S. government securities [member]
Assets
Other investments - current
Financial assets at amortised cost, category [member] \| Non - U.S. government securities [member]
Assets
Other investments - current
Financial assets at amortised cost, category [member] \| Corporates securities [member]
Assets
Other investments - current
Financial assets at amortised cost, category [member] \| Other investments [member]
Assets
Other investments - non-current
Financial assets at fair value through other comprehensive income, category [member]
Assets
Cash and cash equivalents
Other investments - current	108,791	144,502
Other investments - non-current	239,422	18,012
Current trade receivables
Other receivables	48,659	48,659
Total	396,872	211,173
Liabilities
Borrowings C and NC
Trade payables
Finance Lease Liabilities C and NC
Derivative financial instruments
Total
Financial assets at fair value through other comprehensive income, category [member] \| Derivatives [member]
Assets
Derivative financial instruments
Financial assets at fair value through other comprehensive income, category [member] \| Other receivables [member]
Assets
Other receivables	48,659	48,659
Financial assets at fair value through other comprehensive income, category [member] \| Other receivables (non-Financial) [member]
Assets
Other receivables
Financial assets at fair value through other comprehensive income, category [member] \| Fixed Income (time-deposit, zero coupon bonds, commercial papers) [member]
Assets
Other investments - current
Financial assets at fair value through other comprehensive income, category [member] \| U.S. Sovereign Bills [Member]
Assets
Other investments - current
Financial assets at fair value through other comprehensive income, category [member] \| Non - U.S. Sovereign Bills [Member]
Assets
Other investments - current
Financial assets at fair value through other comprehensive income, category [member] \| Certificates of Deposits [member]
Assets
Other investments - current
Financial assets at fair value through other comprehensive income, category [member] \| Commercial Papers [member]
Assets
Other investments - current
Financial assets at fair value through other comprehensive income, category [member] \| Other notes [member]
Assets
Other investments - current
Financial assets at fair value through other comprehensive income, category [member] \| Bonds and other fixed income [member]
Assets
Other investments - current	108,791	144,502
Other investments - non-current	239,422	18,012
Financial assets at fair value through other comprehensive income, category [member] \| U.S. government securities [member]
Assets
Other investments - current		10,211
Financial assets at fair value through other comprehensive income, category [member] \| Non - U.S. government securities [member]
Assets
Other investments - current	20,219	28,637
Financial assets at fair value through other comprehensive income, category [member] \| Corporates securities [member]
Assets
Other investments - current	88,572	105,654
Financial assets at fair value through other comprehensive income, category [member] \| Other investments [member]
Assets
Other investments - non-current
Financial assets at fair value through profit or loss, category [member]
Assets
Cash and cash equivalents	98,183	1,166,697
Other investments - current
Other investments - non-current	7,660	6,922
Current trade receivables
Other receivables
Total	117,292	1,193,548
Liabilities
Borrowings C and NC
Trade payables
Finance Lease Liabilities C and NC
Derivative financial instruments	3,217	1,814
Total	3,217	1,814
Financial assets at fair value through profit or loss, category [member] \| Derivatives [member]
Assets
Derivative financial instruments	11,449	19,929
Financial assets at fair value through profit or loss, category [member] \| Other receivables [member]
Assets
Other receivables
Financial assets at fair value through profit or loss, category [member] \| Other receivables (non-Financial) [member]
Assets
Other receivables
Financial assets at fair value through profit or loss, category [member] \| Fixed Income (time-deposit, zero coupon bonds, commercial papers) [member]
Assets
Other investments - current
Financial assets at fair value through profit or loss, category [member] \| U.S. Sovereign Bills [Member]
Assets
Other investments - current
Financial assets at fair value through profit or loss, category [member] \| Non - U.S. Sovereign Bills [Member]
Assets
Other investments - current
Financial assets at fair value through profit or loss, category [member] \| Certificates of Deposits [member]
Assets
Other investments - current
Financial assets at fair value through profit or loss, category [member] \| Commercial Papers [member]
Assets
Other investments - current
Financial assets at fair value through profit or loss, category [member] \| Other notes [member]
Assets
Other investments - current
Financial assets at fair value through profit or loss, category [member] \| Bonds and other fixed income [member]
Assets
Other investments - current
Other investments - non-current
Financial assets at fair value through profit or loss, category [member] \| U.S. government securities [member]
Assets
Other investments - current
Financial assets at fair value through profit or loss, category [member] \| Non - U.S. government securities [member]
Assets
Other investments - current
Financial assets at fair value through profit or loss, category [member] \| Corporates securities [member]
Assets
Other investments - current
Financial assets at fair value through profit or loss, category [member] \| Other investments [member]
Assets
Other investments - non-current	$ 7,660	$ 6,922

III. Financial Risk Management - Changes in Level 3 Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of fair value measurement of assets [line items]
At the beginning of the year	$ 14,842,991	$ 14,251,299
At the end of the year	13,716,189	14,842,991
Level 3 of fair value hierarchy [member]
Disclosure of fair value measurement of assets [line items]
At the beginning of the year	55,581	52,985
(Decrease) / Addition	(3,604)	2,933
Increase due to business combinations	3,915
Currency translation adjustment and others	427	(337)
At the end of the year	$ 56,319	$ 55,581

- Definition

Expiry date 2020-01-01: The amount of resources: (a) controlled by the entity as a result of past events; and (b) from which future economic benefits are expected to flow to the entity. Effective 2020-01-01: The amount of a present economic resource controlled by the entity as a result of past events. Economic resource is a right that has the potential to produce economic benefits.

+ References + Details

Note 1 - Segment Information (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of operating segments [line items]
Profit (loss) before tax	$ (619,267)	$ 933,710	$ 1,103,107
Contract liabilities	$ 48,700	$ 82,700	$ 62,700
Tenaris [member] \| Government customers [member]
Disclosure of operating segments [line items]
Percentage of entity's revenue	24.00%	21.00%	15.00%
UNITED STATES
Disclosure of operating segments [line items]
Percentage of entity's revenue	26.00%
Elimination of intersegment amounts [member]
Disclosure of operating segments [line items]
Profit (loss) before tax	$ 16,900	$ 36,200	$ 52,400

Note 1 - Segment Information - Reportable Operating Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of operating segments [line items]
IFRS - Net Sales	$ 5,146,734	$ 7,294,055	$ 7,658,588
Operating (loss) income	(663,071)	832,391	871,813
Income (loss) before equity in earnings of non-consolidated companies and income tax	(728,066)	851,674	909,113
Equity in earnings of non-consolidated companies	108,799	82,036	193,994
(Loss) income before income tax	(619,267)	933,710	1,103,107
Capital expenditures	193,322	350,174	349,473
Depreciation and amortization	678,806	539,521	664,357
Tubes [member]
Disclosure of operating segments [line items]
IFRS - Net Sales	4,844,000	6,870,000	7,233,000
Management view - operating income (loss)	(277,000)	857,000	702,000
Difference in cost of sales	(138,000)	(105,000)	112,000
Differences in depreciation and amortization	1,000	(1,000)	(34,000)
Differences in selling, general and administrative expenses	(2,000)	(1,000)	(2,000)
Differences in other operating income (expenses), net	(200,000)	6,000
Operating (loss) income	(616,000)	756,000	778,000
Capital expenditures	189,000	338,000	346,000
Depreciation and amortization	661,000	523,000	645,000
All other segments [member]
Disclosure of operating segments [line items]
IFRS - Net Sales	303,000	424,000	426,000
Management view - operating income (loss)	(50,000)	73,000	81,000
Difference in cost of sales	4,000	3,000	7,000
Differences in depreciation and amortization	(1,000)
Differences in selling, general and administrative expenses		1,000	6,000
Differences in other operating income (expenses), net
Operating (loss) income	(47,000)	77,000	94,000
Capital expenditures	4,000	12,000	3,000
Depreciation and amortization	18,000	17,000	19,000
Reportable segments [member]
Disclosure of operating segments [line items]
IFRS - Net Sales	5,147,000	7,294,000	7,659,000
Management view - operating income (loss)	(327,000)	930,000	783,000
Difference in cost of sales	(134,000)	(102,000)	119,000
Differences in depreciation and amortization		(1,000)	(34,000)
Differences in selling, general and administrative expenses	(2,000)		4,000
Differences in other operating income (expenses), net	(200,000)	6,000
Operating (loss) income	(663,000)	833,000	872,000
Financial income (expense), net	(65,000)	19,000	37,000
Income (loss) before equity in earnings of non-consolidated companies and income tax	(728,000)	852,000	909,000
Equity in earnings of non-consolidated companies	109,000	82,000	194,000
(Loss) income before income tax	(619,000)	934,000	1,103,000
Capital expenditures	193,000	350,000	349,000
Depreciation and amortization	$ 679,000	$ 540,000	$ 664,000

Note 1 - Segment Information - Geographical Information (Details) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2020

Dec. 31, 2019

Dec. 31, 2018

$ 5,146,734

$ 7,294,055

$ 7,658,588

13,716,189

14,842,991

14,251,299

968,148

1,348,160

1,737,366

6,193,181

6,090,017

6,063,908

193,322

350,174

349,473

678,806

539,521

664,357

North America [member]

2,179,949

3,429,911

3,611,509

8,071,574

7,885,120

7,971,311

411,692

612,809

791,190

3,971,101

3,771,570

3,859,060

71,531

169,390

196,220

408,546

276,046

441,705

South America [member]

776,235

1,391,288

1,462,044

1,868,458

2,227,044

2,489,522

115,972

176,173

280,801

1,050,619

1,129,260

1,133,113

63,111

113,999

68,603

106,827

105,308

108,558

Europe [member]

642,793

738,880

724,733

1,461,738

2,282,775

1,913,589

139,427

149,321

215,202

823,057

816,721

848,178

39,691

55,169

77,467

Middle East and Africa [member]

84,518

82,400

82,769

1,227,532

1,382,172

1,559,988

804,559

958,424

588,746

210,194

319,406

383,358

242,939

254,858

94,040

10,452

4,578

2,047

44,259

42,520

10,389

Asia Pacific [member]

320,225

351,804

300,314

552,508

609,663

482,563

90,863

90,451

66,815

105,465

117,608

129,517

8,537

7,038

5,136

34,656

33,247

20,936

Unallocated [member]

^[1]

957,352

879,965

805,568

Disclosure of detailed information about property, plant and equipment [line items]

[1]	For 2020, 2019 and 2018 includes Investments in non-consolidated companies. See note 13.

Note 1 - Segment Information - Tubes Segment Revenues By Market (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of operating segments [line items]
IFRS - Net Sales	$ 5,146,734	$ 7,294,055	$ 7,658,588
Tubes [member]
Disclosure of operating segments [line items]
IFRS - Net Sales	4,844,000	6,870,000	7,233,000
Tubes [member] \| Oil and gas [member]
Disclosure of operating segments [line items]
IFRS - Net Sales	4,073,000	5,757,000	6,042,000
Tubes [member] \| Hydrocarbon processing and power generation [member]
Disclosure of operating segments [line items]
IFRS - Net Sales	371,000	534,000	602,000
Tubes [member] \| Industrial and other [member]
Disclosure of operating segments [line items]
IFRS - Net Sales	$ 400,000	$ 579,000	$ 589,000

- Definition

Expiry date 2020-01-01: The income arising in the course of an entity's ordinary activities. Income is increases in economic benefits during the accounting period in the form of inflows or enhancements of assets or decreases of liabilities that result in an increase in equity, other than those relating to contributions from equity participants. Effective 2020-01-01: The income arising in the course of an entity's ordinary activities. Income is increases in assets, or decreases in liabilities, that result in increases in equity, other than those relating to contributions from holders of equity claims.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2019-01-01
-Paragraph 28
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2019-en-r&anchor=para_28_a&doctype=Standard
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2019-01-01
-Paragraph 23
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2019-en-r&anchor=para_23_a&doctype=Standard
-URIDate 2019-03-27

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2019-01-01
-Paragraph 32
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2019-en-r&anchor=para_32&doctype=Standard
-URIDate 2019-03-27

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2019-01-01
-Paragraph 33
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2019-en-r&anchor=para_33_a&doctype=Standard
-URIDate 2019-03-27

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2019-01-01
-Paragraph 34
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2019-en-r&anchor=para_34&doctype=Standard
-URIDate 2019-03-27

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 82
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_82_a&doctype=Standard
-URIDate 2019-03-27

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 103
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_103&doctype=Standard
-URIDate 2019-03-27

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 102
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_102&doctype=Standard
-URIDate 2019-03-27

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 5
-IssueDate 2019-01-01
-Paragraph 33
-Subparagraph b
-Clause i
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=5&code=ifrs-tx-2019-en-r&anchor=para_33_b_i&doctype=Standard
-URIDate 2019-03-27

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2019-01-01
-Paragraph B12
-Subparagraph b
-Clause v
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2019-en-r&anchor=para_B12_b_v&doctype=Appendix&subtype=B
-URIDate 2019-03-27

Reference 11: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 12
-IssueDate 2019-01-01
-Paragraph B10
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2019-en-r&anchor=para_B10_b&doctype=Appendix&subtype=B
-URIDate 2019-03-27

+ Details

Note 2 - Cost of Sales - Components of Cost of Sales (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Cost of Sales [Abstract]
Inventories at the beginning of the year	$ 2,265,880	$ 2,524,341	$ 2,368,304
Increase in inventory due to business combinations	199,589	52,966
Raw materials, energy, consumables and other	1,545,688	2,709,629	3,400,396
Services and fees	154,976	222,415	275,130
Labor cost	757,359	870,261	855,040
Depreciation of property, plant and equipment	503,725	428,791	432,497
Amortization of intangible assets	8,121	5,948	8,220
Depreciation of right-of-use assets	40,127	28,727
Maintenance expenses	107,764	284,758	185,782
Allowance for obsolescence	35,809	29,138	25,457
Taxes	45,162	100,738	133,308
Other	59,790	115,663	119,507
Cost of sales including discontinued operations	3,458,110	4,849,034	5,435,337
Less: Inventories at the end of the year	(1,636,673)	(2,265,880)	(2,524,341)
Cost of sales	4,087,317	5,107,495	5,279,300
Cost of sales, labor cost severance charges	$ 81,300	$ 17,200	$ 15,000

Note 3 - Selling, General and Administrative Expenses - Components of Selling, General and Administrative Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Selling, general and administrative expense [abstract]
Services and fees	$ 115,883	$ 153,773	$ 128,090
Labor cost	444,436	481,854	470,928
Depreciation of property, plant and equipment	26,814	18,524	16,968
Selling, general and administrative expenses, amortization of intangible assets	82,355	41,967	206,672
Depreciation of right-of-use assets	17,664	15,564
Commissions, freight and other selling expenses	310,815	441,442	491,555
Provisions for contingencies	11,957	28,565	23,498
Allowances for doubtful accounts	4,644	(16,256)	1,751
Taxes	63,234	110,876	71,110
Other	41,425	89,665	99,404
Total selling, general and administrative expense	1,119,227	1,365,974	1,509,976
Selling, general and administrative expenses, labor cost severance charges	$ 61,200	$ 7,400	$ 10,200

Note 4 - Labor Costs - Summary of Labor Costs (Included in Cost of Sales and in Selling, General and Administrative Expenses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
4. Labor costs (included in Cost of sales and in Selling, general and administrative expenses)
Wages, salaries and social security costs	$ 1,036,211	$ 1,274,474	$ 1,250,783
Severance indemnities	142,458	24,637	25,225
Defined contribution plans	12,442	12,663	13,217
Pension benefits - defined benefit plans	11,097	18,207	15,390
Employee retention and long term incentive program	(413)	22,134	21,353
Total employee benefits expense	$ 1,201,795	$ 1,352,115	$ 1,325,968

Note 4 - Labor Costs - Labor Costs (Included in Cost of Sales and in Selling, General and Administrative Expenses) - Number of Employees (Details)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of geographical areas [line items]
Number of employees	19,028	23,200	22,967
ARGENTINA
Disclosure of geographical areas [line items]
Number of employees	4,376	5,405	5,427
MEXICO
Disclosure of geographical areas [line items]
Number of employees	4,501	5,370	5,595
UNITED STATES
Disclosure of geographical areas [line items]
Number of employees	1,596	2,255	2,382
ITALY
Disclosure of geographical areas [line items]
Number of employees	2,039	2,144	2,155
ROMANIA
Disclosure of geographical areas [line items]
Number of employees	1,552	1,815	1,852
BRAZIL
Disclosure of geographical areas [line items]
Number of employees	1,360	1,360	1,287
COLOMBIA
Disclosure of geographical areas [line items]
Number of employees	746	1,040	1,082
CANADA
Disclosure of geographical areas [line items]
Number of employees	561	772	1,030
INDONESIA
Disclosure of geographical areas [line items]
Number of employees	521	616	554
JAPAN
Disclosure of geographical areas [line items]
Number of employees	399	400	399
Other geographical areas [member]
Disclosure of geographical areas [line items]
Number of employees	1,377	2,023	1,204

Note 5 - Impairment charge (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Growth rate used in current estimate of value in use		2.00%
Impairment charge	$ 622,000	$ 622,402
Discount rate, measurement input [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Percentage of reasonably possible increase (decrease) in key assumption resulting additional impairment		1.00%
Growth rate, measurement input [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Percentage of reasonably possible increase (decrease) in key assumption resulting additional impairment		(1.00%)
Projected change rate in future cash flows, measurement input [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Percentage of reasonably possible increase (decrease) in key assumption resulting additional impairment		(5.00%)
Tubes [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment charge	582,000
Top of range [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Discount rate used in current estimate of value in use		13.60%
Bottom of range [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Discount rate used in current estimate of value in use		8.00%
OCTG (USA) [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment charge	225,000	$ 225,000
IPSCO [Member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment charge	357,000	357,000
Coiled Tubing [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment charge	4,000	4,000
Rods USA [Member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment charge	$ 36,000	$ 36,000

Note 5 - Impairment charge - Impairment allocated by CGU (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment charge	$ 622,000	$ 622,402
OCTG (USA) [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Assets before impairment		544,000
Impairment charge	225,000	225,000
Assets after impairment		319,000
IPSCO [Member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Assets before impairment		1,169,000
Impairment charge	357,000	357,000
Assets after impairment		812,000
Coiled Tubing [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Assets before impairment		108,000
Impairment charge	4,000	4,000
Assets after impairment		104,000
Rods USA [Member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Assets before impairment		73,000
Impairment charge	$ 36,000	36,000
Assets after impairment		$ 37,000

Note 6 - Other operating income and expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other operating income:
Net income from other sales	$ 9,891	$ 8,651	$ 3,604
Net rents	5,501	5,089	4,909
Other	18,001	8,025	6,546
Recovery on allowance for doubtful receivables		1,239
Other income	33,393	23,004	15,059
Other operating expenses:
Contributions to welfare projects and non-profits organizations	12,989	11,199	11,379
Allowance for doubtful receivables	1,263		1,179
Other expense	$ 14,252	$ 11,199	$ 12,558

Note 7 - Financial Results (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Financial Results [Abstract]
Interest income (expense)	$ 6.5	$ 7.6	$ 3.6

Note 7 - Financial Results - Financial Income (Cost) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Financial Results [Abstract]
Interest Income	$ 21,625	$ 48,061	$ 42,244
Net result on changes in FV of financial assets at FVPL		(64)	(2,388)
Impairment result on financial assets at FVTOCI	(3,238)
Finance income	18,387	47,997	39,856
Finance cost	(27,014)	(43,381)	(36,942)
Net foreign exchange transactions results	(74,422)	27,868	28,845
Foreign exchange derivatives contracts results	19,644	(11,616)	6,576
Other	(1,590)	(1,585)	(1,035)
Other financial results	(56,368)	14,667	34,386
Net financial results	$ (64,995)	$ 19,283	$ 37,300

Note 8 - Income Tax (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of geographical areas [line items]
After tax effect of expense not deductible in determining profit (loss)	$ 61	$ 66	$ 65
Charge related to withholding taxes for intra group international operations	$ 10	$ 34	$ 26

Note 8 - Income Tax - Summary of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Line Items [Line Items]
Current tax	$ (121,048)	$ (299,692)	$ (343,104)
Deferred tax	97,898	97,240	113,897
Tax income (expense)	$ 23,150	$ 202,452	$ 229,207

- Definition

The aggregate amount included in the determination of profit (loss) for the period in respect of current tax and deferred tax. [Refer: Current tax expense (income); Deferred tax expense (income)]

+ References + Details

Note 8 - Income Tax - Summary of Differences Between Income Tax and Theoretical Amount Using Tax Rate in Each Country (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Line Items [Line Items]
(Loss) income before income tax		$ (619,267)	$ 933,710	$ 1,103,107
Impairment charge	$ 622,000	622,402
Income before income tax without impairment charges		3,135	933,710	1,103,107
Tax calculated at the tax rate in each country		21,052	(186,752)	(207,422)
Effect of currency translation on tax base		(72,936)	(53,296)	(77,552)
Changes in the tax rates		(958)	13	(1,824)
Utilization of previously unrecognized tax losses		98	547
Tax revaluation, withholding tax and others		29,594	37,036	57,591
Tax charge		$ 23,150	$ 202,452	$ 229,207

Note 9 - Dividends Distribution (Details Textual) - USD ($) $ / shares in Units, $ in Thousands								1 Months Ended	12 Months Ended
	Nov. 25, 2020	Nov. 04, 2020	Nov. 20, 2019	May 22, 2019	Nov. 21, 2018	May 23, 2018	Nov. 22, 2017	Nov. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	May 06, 2019	May 02, 2018
Disclosure of Dividends Distribution [Abstract]
Dividends recognised as distributions to owners per share (in dollars per share)		$ 0.07
Dividends payable, amount per ads (in dollars per share)		$ 0.14
Payments for dividends approved		$ 82,600
Dividends recognised as distributions to owners	$ 82,600		$ 153,000	$ 484,000		$ 484,000		$ 153,000	$ 87,938	$ 485,827	$ 487,681
Dividends payable, amount per share including interim dividend (in dollars per share)												$ 0.41	$ 0.41
Dividends payable, amount per ADS including interim dividend (in dollars per share)												$ 0.82	$ 0.82
Dividends paid, ordinary shares per share (in dollars per share)	$ 0.07	$ 0.07		$ 0.28	$ 0.13	$ 0.28	$ 0.13
Dividends paid, per ADS (in dollars per share)	$ 0.14			$ 0.56	$ 0.26	$ 0.56	$ 0.26

Note 10 - Property, Plant and Equipment, Net (Details Textual) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about property, plant and equipment [abstract]
Property, plant and equipment, capitalized interest	$ 33.6	$ 35.4

Note 10 - Property, Plant and Equipment, Net - Components of Property, Plant and Equipment, Net (Details) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2020

Dec. 31, 2019

$ 6,090,017

$ 6,063,908

Land and civil buildings [member]

6,193,181

6,090,017

Disclosure of detailed information about property, plant and equipment [line items]

677,671

Industrial buildings, plant and production equipment [member]

707,126

677,671

Disclosure of detailed information about property, plant and equipment [line items]

5,166,678

Vehicles, furniture and fixtures [member]

5,249,425

5,166,678

Disclosure of detailed information about property, plant and equipment [line items]

76,758

Construction in progress [member]

72,511

76,758

Disclosure of detailed information about property, plant and equipment [line items]

108,308

Spare parts and equipment [member]

102,226

108,308

Disclosure of detailed information about property, plant and equipment [line items]

60,602

Gross carrying amount [member]

61,893

60,602

Disclosure of detailed information about property, plant and equipment [line items]

13,836,586

13,421,982

70,291

(43,307)

503,438

^[1]

178,739

^[2]

167,755

313,915

(82,416)

(38,975)

2,351

4,232

Gross carrying amount [member] | Land and civil buildings [member]

14,498,005

13,836,586

Disclosure of detailed information about property, plant and equipment [line items]

799,139

732,578

(545)

(1,611)

39,622

^[1]

59,468

^[2]

1,451

(5,964)

(35)

5,881

8,723

Gross carrying amount [member] | Industrial buildings, plant and production equipment [member]

839,584

799,139

Disclosure of detailed information about property, plant and equipment [line items]

12,468,813

12,121,569

72,650

(38,961)

440,366

^[1]

115,908

^[2]

1,524

1,178

(61,281)

(27,153)

157,473

296,272

Gross carrying amount [member] | Vehicles, furniture and fixtures [member]

13,079,545

12,468,813

Disclosure of detailed information about property, plant and equipment [line items]

399,724

377,260

443

(1,615)

7,195

^[1]

1,733

^[2]

620

1,107

(8,811)

(7,110)

15,586

28,349

Gross carrying amount [member] | Construction in progress [member]

414,757

399,724

Disclosure of detailed information about property, plant and equipment [line items]

108,308

127,378

(2,095)

(864)

16,255

^[1]

1,630

^[2]

157,315

299,412

(968)

(2,120)

(176,589)

(317,128)

Gross carrying amount [member] | Spare parts and equipment [member]

102,226

108,308

Disclosure of detailed information about property, plant and equipment [line items]

60,602

63,197

(162)

(256)

^[1]

^[2]

6,845

12,202

(5,392)

(2,557)

(11,984)

Accumulated depreciation, amortisation and impairment [member]

61,893

60,602

Disclosure of detailed information about property, plant and equipment [line items]

7,746,569

7,358,074

56,677

(26,878)

(64,834)

(31,542)

36,000

(127)

(400)

530,539

447,315

Accumulated depreciation, amortisation and impairment [member] | Land and civil buildings [member]

8,304,824

7,746,569

Disclosure of detailed information about property, plant and equipment [line items]

121,468

110,914

(288)

(420)

(89)

(73)

(1)

(362)

11,368

11,409

Accumulated depreciation, amortisation and impairment [member] | Industrial buildings, plant and production equipment [member]

132,458

121,468

Disclosure of detailed information about property, plant and equipment [line items]

7,302,135

6,936,900

56,560

(24,973)

(57,897)

(25,580)

36,000

349

(38)

492,973

415,826

Accumulated depreciation, amortisation and impairment [member] | Vehicles, furniture and fixtures [member]

7,830,120

7,302,135

Disclosure of detailed information about property, plant and equipment [line items]

322,966

310,260

405

(1,485)

(6,848)

(5,889)

(475)

26,198

20,080

Accumulated depreciation, amortisation and impairment [member] | Construction in progress [member]

342,246

322,966

Disclosure of detailed information about property, plant and equipment [line items]

Accumulated depreciation, amortisation and impairment [member] | Spare parts and equipment [member]

Disclosure of detailed information about property, plant and equipment [line items]

Disclosure of reconciliation of changes in intangible assets and goodwill [line items]

[1]	Related to IPSCO acquisition. See note 32.
[2]	Related to SSPC acquisition. See note 32.

Note 11 - Intangible Assets, Net (Details Textual) $ in Millions	Dec. 31, 2020 USD ($)
Disclosure of reconciliation of changes in goodwill [line items]
Goodwill at end of period	$ 1,086.0
North America [member]
Disclosure of reconciliation of changes in goodwill [line items]
Goodwill at end of period	939.2
South America [member]
Disclosure of reconciliation of changes in goodwill [line items]
Goodwill at end of period	111.1
Europe [member]
Disclosure of reconciliation of changes in goodwill [line items]
Goodwill at end of period	2.0
Middle East and Africa [member]
Disclosure of reconciliation of changes in goodwill [line items]
Goodwill at end of period	$ 33.7

Note 11 - Intangible Assets, Net - Intangible Assets and Goodwill (Details) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2020

Dec. 31, 2019

$ 1,561,559

Information system projects [member]

1,429,056

$ 1,561,559

Disclosure of reconciliation of changes in intangible assets and goodwill [line items]

68,533

Licenses, patents and trademarks [member]

59,993

68,533

Disclosure of reconciliation of changes in intangible assets and goodwill [line items]

^[1]

89,970

Disclosure of reconciliation of changes in intangible assets and goodwill [line items]

^[1]

167,969

89,970

Goodwill [member]

1,320,245

Disclosure of reconciliation of changes in intangible assets and goodwill [line items]

1,085,968

1,320,245

82,811

Gross carrying amount [member]

115,126

82,811

Disclosure of reconciliation of changes in intangible assets and goodwill [line items]

5,326,500

5,189,988

(3,730)

(2,955)

526,846

^[2]

114,466

^[3]

25,567

36,259

(1,393)

(4,665)

(4,825)

(6,593)

Gross carrying amount [member] | Information system projects [member]

5,868,965

5,326,500

Disclosure of reconciliation of changes in intangible assets and goodwill [line items]

604,870

580,622

1,108

(1,917)

11,563

^[2]

405

^[3]

24,965

35,487

(1,393)

(4,665)

(3,761)

(5,062)

Gross carrying amount [member] | Licenses, patents and trademarks [member]

637,352

604,870

Disclosure of reconciliation of changes in intangible assets and goodwill [line items]

^[1]

463,742

464,571

^[1]

220

(70)

^[1]

87,000

^[2]

^[3]

^[1]

602

772

^[1]

^[1]

(1,064)

(1,531)

Gross carrying amount [member] | Goodwill [member]

^[1]

550,500

463,742

Disclosure of reconciliation of changes in intangible assets and goodwill [line items]

2,117,837

2,085,936

(5,058)

(968)

357,183

^[2]

32,869

^[3]

Gross carrying amount [member] | Customer-related intangible assets [member]

2,469,962

2,117,837

Disclosure of reconciliation of changes in intangible assets and goodwill [line items]

2,140,051

2,058,859

71,100

^[2]

81,192

^[3]

Accumulated depreciation, amortisation and impairment [member]

2,211,151

2,140,051

Disclosure of reconciliation of changes in intangible assets and goodwill [line items]

3,764,941

3,724,023

889

(1,734)

586,402

931

(3,730)

(5,263)

90,476

47,915

Accumulated depreciation, amortisation and impairment [member] | Information system projects [member]

4,439,909

3,764,941

Disclosure of reconciliation of changes in intangible assets and goodwill [line items]

536,337

513,984

890

(1,734)

931

(3,730)

(4,850)

42,931

28,937

Accumulated depreciation, amortisation and impairment [member] | Licenses, patents and trademarks [member]

577,359

536,337

Disclosure of reconciliation of changes in intangible assets and goodwill [line items]

^[1]

373,772

373,466

^[1]

(1)

^[1]

^[1]

^[1]

(413)

^[1]

8,760

719

Accumulated depreciation, amortisation and impairment [member] | Goodwill [member]

^[1]

382,531

373,772

Disclosure of reconciliation of changes in intangible assets and goodwill [line items]

797,592

586,402

Accumulated depreciation, amortisation and impairment [member] | Customer-related intangible assets [member]

1,383,994

797,592

Disclosure of reconciliation of changes in intangible assets and goodwill [line items]

2,057,240

2,038,981

38,785

18,259

Disclosure of maturity analysis of operating lease payments [line items]

$ 2,096,025

$ 2,057,240

[1]	Includes Proprietary Technology.
[2]	Related to IPSCO acquisition. See note 32.
[3]	Related to SSPC acquisition. See note 32.

Note 11 - Intangible Assets, Net - Goodwill Allocated by CGU (Details) $ in Millions	Dec. 31, 2020 USD ($)
Disclosure of information for cash-generating units [line items]
Goodwill	$ 1,086
Tamsa (Hydril and other) [member]
Disclosure of information for cash-generating units [line items]
Goodwill	365
Siderca (Hydril and other) [member]
Disclosure of information for cash-generating units [line items]
Goodwill	358
Hydril [member]
Disclosure of information for cash-generating units [line items]
Goodwill	309
Other CGU [member]
Disclosure of information for cash-generating units [line items]
Goodwill	54
Tubes [member]
Disclosure of information for cash-generating units [line items]
Goodwill	166
Tubes [member] \| Tamsa (Hydril and other) [member]
Disclosure of information for cash-generating units [line items]
Goodwill	19
Tubes [member] \| Siderca (Hydril and other) [member]
Disclosure of information for cash-generating units [line items]
Goodwill	93
Tubes [member] \| Hydril [member]
Disclosure of information for cash-generating units [line items]
Goodwill
Tubes [member] \| Other CGU [member]
Disclosure of information for cash-generating units [line items]
Goodwill	54
Tubes [member] \| Hydrill acquisition [member]
Disclosure of information for cash-generating units [line items]
Goodwill	920
Tubes [member] \| Hydrill acquisition [member] \| Tamsa (Hydril and other) [member]
Disclosure of information for cash-generating units [line items]
Goodwill	346
Tubes [member] \| Hydrill acquisition [member] \| Siderca (Hydril and other) [member]
Disclosure of information for cash-generating units [line items]
Goodwill	265
Tubes [member] \| Hydrill acquisition [member] \| Hydril [member]
Disclosure of information for cash-generating units [line items]
Goodwill	309
Tubes [member] \| Hydrill acquisition [member] \| Other CGU [member]
Disclosure of information for cash-generating units [line items]
Goodwill

Note 12 - Right-of-use Assets, Net and Lease Liabilities (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of maturity analysis of operating lease payments [line items]
Leases paid in advance			$ 4.0
Expense relating to short-term leases for which recognition exemption has been used	$ 1.7	$ 15.1
Expense relating to leases of low-value assets for which recognition exemption has been used	$ 3.2	$ 1.3
Not later than one year [member]
Disclosure of maturity analysis of operating lease payments [line items]
Remaining lease payments to be made, percentage	16.90%
Later than one year and not later than five years [member]
Disclosure of maturity analysis of operating lease payments [line items]
Remaining lease payments to be made, percentage	40.50%
Later than five years [member]
Disclosure of maturity analysis of operating lease payments [line items]
Remaining lease payments to be made, percentage	42.60%

Note 12 - Right-of-use Assets, Net and Lease Liabilities - Evolution of Right-of-use Assets (Details) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2020

Dec. 31, 2019

$ 233,126

Gross carrying amount [member]

241,953

$ 233,126

Disclosure of maturity analysis of operating lease payments [line items]

275,720

238,400

437

(74)

24,747

^[1]

2,267

^[2]

59,141

41,442

117

(26,257)

(6,315)

Accumulated depreciation, amortisation and impairment [member]

333,905

275,720

Disclosure of maturity analysis of operating lease payments [line items]

42,594

243

57,791

44,291

117

(8,793)

(1,705)

Land and civil buildings [member]

91,952

42,594

Disclosure of maturity analysis of operating lease payments [line items]

27,807

Land and civil buildings [member] | Gross carrying amount [member]

26,790

27,807

Disclosure of maturity analysis of operating lease payments [line items]

36,137

27,713

(839)

(88)

3,461

^[1]

229

^[2]

11,534

9,292

439

(8,800)

(1,009)

Land and civil buildings [member] | Accumulated depreciation, amortisation and impairment [member]

41,932

36,137

Disclosure of maturity analysis of operating lease payments [line items]

8,330

(92)

(3)

13,200

8,514

(2,876)

(3,420)

(181)

Industrial buildings, plant and production equipment [member]

15,142

8,330

Disclosure of maturity analysis of operating lease payments [line items]

194,808

Industrial buildings, plant and production equipment [member] | Gross carrying amount [member]

205,365

194,808

Disclosure of maturity analysis of operating lease payments [line items]

225,389

202,352

746

13,730

^[1]

2,038

^[2]

42,573

24,985

(458)

496

(8,622)

(4,488)

Industrial buildings, plant and production equipment [member] | Accumulated depreciation, amortisation and impairment [member]

273,358

225,389

Disclosure of maturity analysis of operating lease payments [line items]

30,581

145

37,671

31,869

1,702

(62)

(2,106)

(1,229)

Vehicles, furniture and fixtures [member]

67,993

30,581

Disclosure of maturity analysis of operating lease payments [line items]

10,511

Vehicles, furniture and fixtures [member] | Gross carrying amount [member]

9,798

10,511

Disclosure of maturity analysis of operating lease payments [line items]

14,194

8,335

530

7,556

^[1]

^[2]

5,034

7,165

136

(496)

(8,835)

(818)

Vehicles, furniture and fixtures [member] | Accumulated depreciation, amortisation and impairment [member]

18,615

14,194

Disclosure of maturity analysis of operating lease payments [line items]

3,683

190

6,920

3,908

1,291

(3,267)

(295)

Presentation of leases for lessee [abstract]

$ 8,817

$ 3,683

[1]	Related to IPSCO acquisition. See note 32.
[2]	Related to SSPC acquisition.

Note 12 - Right-of-use Assets, Net and Lease Liabilities - Evolution of Lease Liability (Details) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2020

Dec. 31, 2019

Opening net book amount

$ 230,167

$ 234,149

26,046

2,267

7,656

2,690

Disclosure of unconsolidated structured entities [abstract]

58,536

36,957

Cancellations

(17,529)

(4,688)

Repayments

^[1]

(51,666)

(43,974)

Interest accrued

4,133

2,766

Ending net book amount

$ 257,343

$ 230,167

[1]	Repayments include capital and interest.

Note 13 - Investments in Non-consolidated Companies (Details Textual)	12 Months Ended
	Dec. 31, 2020 USD ($) $ / shares	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2020 R$ / shares	Feb. 19, 2019 USD ($)
Disclosure of unconsolidated structured entities [line items]
Dividends received from associates, classified as investing activities	$ 278,000	$ 28,974,000	$ 25,722,000
Total investments in subsidiaries, joint ventures and associates	$ 957,352,000	879,965,000	$ 805,568,000
Several banks, to refinance obligations [member]
Disclosure of unconsolidated structured entities [line items]
Debt service coverage ratio, covered, percent	22.00%
Letters of credit, covered	$ 9,800,000
Ternium and Usiminas [member]
Disclosure of unconsolidated structured entities [line items]
Dividends received from associates, classified as investing activities	300,000	$ 29,000,000
Usiminas [member]
Disclosure of unconsolidated structured entities [line items]
Fair value of investments in associates for which there are quoted market prices	113,800,000
Total investments in subsidiaries, joint ventures and associates	$ 65,100,000
Usiminas [member] \| Ordinary shares [member]
Disclosure of unconsolidated structured entities [line items]
Closing price, per share (in BRL per share) \| (per share)	$ 3.02			R$ 15.69
Usiminas [member] \| Preference shares [member]
Disclosure of unconsolidated structured entities [line items]
Closing price, per share (in BRL per share) \| (per share)	$ 2.81			R$ 14.61
Usiminas [member] \| CONFAB INDUSTRIAL S.A. and subsidiaries [member]
Disclosure of unconsolidated structured entities [line items]
Proportion of voting rights held in associate	5.19%	5.19%
Usiminas [member] \| Ternium S.A. [member]
Disclosure of unconsolidated structured entities [line items]
Proportion of voting rights held in associate	3.07%
Proportion of ownership interest in associate	5.19%
Ternium S.A. [member]
Disclosure of unconsolidated structured entities [line items]
Closing price, per ads (in dollars per share)	$ 29.08
Fair value of investments in associates for which there are quoted market prices	668,000,000
Total investments in subsidiaries, joint ventures and associates	$ 830,000,000
Proportion of ownership interest in associate	11.46%
Techgen s.a. [member]
Disclosure of unconsolidated structured entities [line items]
Total investments in subsidiaries, joint ventures and associates	$ 19,500,000
Proportion of ownership interest in associate	22.00%
Provision for exposure to transportation capacity agreements	$ 48,800,000
Provision for exposure to purchase and other service agreements	900,000
Provision for exposure to the purchase of clean energy certificates	17,600,000
Proceeds From (Repayments of Loans) Receivable From Related Parties		$ 40,500,000
Loans and receivables	$ 58,100,000
Proportion of corporate guarantee covering obligations	22.00%	22.00%
Techgen s.a. [member] \| Techgen s.a. [member]
Disclosure of unconsolidated structured entities [line items]
Proportion of ownership interest in associate	48.00%
Techgen s.a. [member] \| Several banks, to refinance obligations [member]
Disclosure of unconsolidated structured entities [line items]
Debt instruments issued					$ 640,000,000
Techgen s.a. [member] \| Tecpetrol International S.A. [member]
Disclosure of unconsolidated structured entities [line items]
Proportion of ownership interest in associate	30.00%
Global Pipe Company [Member]
Disclosure of unconsolidated structured entities [line items]
Total investments in subsidiaries, joint ventures and associates	$ 23,400,000
Proportion of ownership interest in associate	35.00%
Global Pipe Company [Member] \| Saudi Steel Pipe Company [member]
Disclosure of unconsolidated structured entities [line items]
Corporate Guarantee Covering Obligations	$ 131,500,000

Note 13 - Investments in Non-consolidated Companies - Summary of Investments in Non-consolidated Companies (Details) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2020

Dec. 31, 2019

Dec. 31, 2018

At the beginning of the year

$ 879,965

$ 805,568

Equity in earnings of non-consolidated companies

^[1]

(31,977)

(10,781)

$ 1,848

108,799

82,036

Dividends and distributions received

20,635

^[2]

(861)

(28,037)

Increase / (decrease) in equity reserves and others

19,610

1,426

(9,066)

Disclosure of unconsolidated structured entities [line items]

$ 957,352

$ 879,965

$ 805,568

[1]	For 2018 and 2019 Tenaris recognized its share over the effects on the adoption of IAS 29, “Financial Reporting in Hyperinflationary Economies” by Ternium in other comprehensive income as a currency translation adjustment. In 2020 Ternium changed the functional currency of its Argentine subsidiary to U.S. dollar and IAS 29 is no longer applicable.
[2]	Related to Ternium and Usiminas. During 2020 and 2019 $0.3 million and $29.0 million respectively were collected.

Note 13 - Investments in Non-consolidated Companies - Principal Non-consolidated Companies (Details) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2020

Dec. 31, 2019

Dec. 31, 2018

Disclosure of unconsolidated structured entities [line items]

$ 957,352

$ 879,965

$ 805,568

Ternium S.A. [member]

11.46%

Ternium S.A. [member] | LUXEMBOURG

$ 830,000

Disclosure of unconsolidated structured entities [line items]

^[1]

11.46%

Disclosure of unconsolidated structured entities [line items]

^[1]

$ 830,028

$ 751,105

Usiminas [member]

Usiminas [member] | BRAZIL

$ 65,100

Disclosure of unconsolidated structured entities [line items]

^[2]

3.07%

Disclosure of unconsolidated structured entities [line items]

^[2]

$ 65,144

$ 74,593

Techgen s.a. [member]

22.00%

Techgen s.a. [member] | MEXICO

$ 19,500

Disclosure of unconsolidated structured entities [line items]

22.00%

Global Pipe Company [Member]

$ 19,536

$ 9,888

Disclosure of unconsolidated structured entities [line items]

35.00%

Global Pipe Company [Member] | SAUDI ARABIA

$ 23,400

Disclosure of unconsolidated structured entities [line items]

35.00%

Disclosure of unconsolidated structured entities [line items]

$ 23,421

$ 22,550

Other [member]

Disclosure of detailed information about borrowings [line items]

$ 19,223

$ 21,829

[1]	Including treasury shares.
[2]	At December 31, 2020 and 2019 the voting rights were 5.19%.

Note 13 - Investments in Non-consolidated Companies - Summary of Selected Financial Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of unconsolidated structured entities [line items]
Non-current assets	$ 9,428,517	$ 9,172,384
Current assets	4,287,672	5,670,607
Total assets	13,716,189	14,842,991	$ 14,251,299
Non-current liabilities	1,103,241	876,162
Current liabilities	1,166,475	1,780,457
Total liabilities	2,269,716	2,656,619
Equity	11,446,473	12,186,372	11,875,492	$ 11,588,988
Non-controlling interests	183,585	197,414
Revenues	5,146,734	7,294,055	7,658,588
Gross profit	1,059,417	2,186,560	2,379,288
Net income for the year attributable to owners of the parent	(634,418)	742,686	876,063
Total comprehensive income for the year, net of tax, attributable to owners of the parent	(643,435)	690,095	$ 776,713
Ternium S.A. [member]
Disclosure of unconsolidated structured entities [line items]
Non-current assets	8,289,460	8,757,320
Current assets	4,566,775	4,178,213
Total assets	12,856,235	12,935,533
Non-current liabilities	2,559,485	3,452,535
Current liabilities	1,853,597	1,768,125
Total liabilities	4,413,082	5,220,660
Equity	8,443,153	7,714,873
Revenues	8,735,435	10,192,818
Gross profit	1,635,512	1,740,378
Net income for the year attributable to owners of the parent	778,468	564,269
Total comprehensive income for the year, net of tax, attributable to owners of the parent	666,667	445,473
Usiminas [member]
Disclosure of unconsolidated structured entities [line items]
Non-current assets	3,487,317	4,335,662
Current assets	2,276,368	2,198,449
Total assets	5,763,685	6,534,111
Non-current liabilities	1,661,605	1,955,395
Current liabilities	861,912	716,930
Total liabilities	2,523,517	2,672,325
Equity	3,240,168	3,861,786
Revenues	3,132,949	3,790,206
Gross profit	624,199	478,141
Net income for the year attributable to owners of the parent	$ 106,361	$ 52,779

Note 14 - Receivables - Non Current - Components of Receivables Non Current (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Trade and other non-current receivables [abstract]
Employee advances and loans	$ 4,563	$ 6,008
Tax credits	18,046	20,065
Receivables from related parties	62,790	59,999
Legal deposits	8,600	12,378
Advances to suppliers and other advances	4,803	3,772
Receivable Venezuelan subsidiaries	48,659	48,659
Others	6,842	6,222
Trade and other non-current receivables before the allowance for doubtful accounts	$ 154,303	$ 157,103

Note 15 - Inventories, Net - Components of Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Classes of current inventories [abstract]
Finished goods	$ 691,922	$ 968,329
Goods in process	417,097	612,888
Raw materials	143,558	221,954
Supplies	488,802	486,411
Goods in transit	158,929	194,015
Inventories, Gross	1,900,308	2,483,597
Allowance for obsolescence, see note 24 (i)	(263,635)	(217,717)
Total current inventories	$ 1,636,673	$ 2,265,880

Note 16 - Receivables and Prepayments, Net - Summary of Receivables and Prepayments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current prepayments and current accrued income [abstract]
Prepaid expenses and other receivables	$ 26,457	$ 30,579
Government entities	3,075	1,867
Employee advances and loans	4,672	8,189
Advances to suppliers and other advances	14,661	17,180
Government tax refunds on exports	2,723	670
Receivables from related parties	16,217	19,837
Miscellaneous	13,961	31,145
Receivables and prepayments, gross	81,766	109,467
Allowance for other doubtful accounts, see note 24 (i)	(3,917)	(4,892)
Current prepayments and other current assets	$ 77,849	$ 104,575

Note 17 - Current Tax Assets and Liabilities - Summary of Current Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Disclosure of Current Tax Receivables and Payables [Abstract]
V.A.T. credits	$ 106,293	$ 112,161
Prepaid taxes	30,091	55,227
Current tax assets, current	$ 136,384	$ 167,388

Note 17 - Current Tax Assets and Liabilities - Summary of Current Tax Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Disclosure of Current Tax Receivables and Payables [Abstract]
Income tax liabilities	$ 27,616	$ 64,994
V.A.T. liabilities	9,933	9,953
Other taxes	53,044	52,678
Current tax liabilities, current	$ 90,593	$ 127,625

Note 18 - Trade Receivables, Net - Summary of Current Trade Receivables (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Trade and other receivables [abstract]
Current accounts	$ 1,017,663	$ 1,387,494
Receivables from related parties	4,161	9,448
Current trade receivables, gross	1,021,824	1,396,942
Allowance for doubtful accounts, see note 24 (i)	(53,676)	(48,782)
Current trade receivables	$ 968,148	$ 1,348,160	$ 1,737,366

Note 18 - Trade Receivables, Net - Summary of the Aging of Trade Receivables (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of financial assets that are either past due or impaired [line items]
Guaranteed	$ 191,514	$ 234,427
Not guaranteed	830,310	1,162,515
Guaranteed and not guaranteed	$ 1,021,824	$ 1,396,942
Expected loss rate	0.07%	0.09%
Allowances for doubtful accounts	$ (721)	$ (1,294)
Nominative allowances for doubtful accounts	(52,955)	(47,488)
Net Value	968,148	1,348,160	$ 1,737,366
Current trade receivables, not due [member]
Disclosure of financial assets that are either past due or impaired [line items]
Guaranteed	170,796	205,764
Not guaranteed	655,132	948,449
Guaranteed and not guaranteed	$ 825,928	$ 1,154,213
Expected loss rate	0.04%	0.04%
Allowances for doubtful accounts	$ (321)	$ (529)
Nominative allowances for doubtful accounts	(718)
Net Value	824,889	1,153,684
Current trade receivables, past due, less than 180 days [member]
Disclosure of financial assets that are either past due or impaired [line items]
Guaranteed	18,778	26,899
Not guaranteed	116,802	157,960
Guaranteed and not guaranteed	$ 135,580	$ 184,859
Expected loss rate	0.23%	0.24%
Allowances for doubtful accounts	$ (331)	$ (455)
Nominative allowances for doubtful accounts	(1,011)	(1,922)
Net Value	134,238	182,482
Current trade receivables, past due, greater than 180 days [member]
Disclosure of financial assets that are either past due or impaired [line items]
Guaranteed	1,940	1,764
Not guaranteed	58,376	56,106
Guaranteed and not guaranteed	$ 60,316	$ 57,870
Expected loss rate	0.72%	0.57%
Allowances for doubtful accounts	$ (69)	$ (310)
Nominative allowances for doubtful accounts	(51,226)	(45,566)
Net Value	$ 9,021	$ 11,994

Note 19 - Cash and Cash Equivalents and Other Investments - Components of Cash and Cash Equivalents and Other Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash and cash equivalents
Cash at banks	$ 117,807	$ 118,314
Liquidity funds	98,183	1,166,697
Short – term investments	368,691	269,288
Total cash and cash equivalents	584,681	1,554,299	$ 428,361
Other investments - current
Fixed income (time-deposit, zero coupon bonds, commercial papers)	763,697	65,874
Bonds and other fixed income	108,791	144,502
Other investments	872,488	210,376
Other investments - Non-current
Bonds and other fixed income	239,422	18,012
Others	7,660	6,922
Other investments	$ 247,082	$ 24,934

Note 20 - Borrowings - Non-current and Current Borrowings (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about borrowings [line items]
Non-current costs of issue of debt	$ (145)	$ (16)
Total non-current portion of non-current borrowings	315,739	40,880
Current costs of issue of debt		(10)
Total current borrowings and current portion of non-current borrowings	303,268	781,272
Total Borrowings	619,007	822,152
Bank borrowings [member]
Disclosure of detailed information about borrowings [line items]
Non-current borrowings before costs of issue of debt	315,884	40,896
Current borrowings before costs of issue of debt	303,170	781,258
Bank overdrafts [member]
Disclosure of detailed information about borrowings [line items]
Current borrowings before costs of issue of debt	$ 98	$ 24

Note 20 - Borrowings - Maturity of Borrowings (Details) - USD ($)
$ in Thousands

Dec. 31, 2020

Dec. 31, 2019

$ 619,007

$ 822,152

^[1]

15,933

12,532

Not later than one year [member]

634,940

834,684

Disclosure of detailed information about borrowings [line items]

303,268

781,272

^[1]

9,829

11,370

Later than one year and not later than two years [member]

313,097

792,642

Disclosure of detailed information about borrowings [line items]

104,147

17,307

^[1]

5,068

1,045

Later than two years and not later than three years [member]

109,215

18,352

Disclosure of detailed information about borrowings [line items]

207,595

23,573

^[1]

1,014

117

Later than three years and not later than four years [member]

208,609

23,690

Disclosure of detailed information about borrowings [line items]

3,997

^[1]

Later than four years and not later than five years [member]

4,019

Disclosure of detailed information about borrowings [line items]

^[1]

Later than five years [member]

Disclosure of detailed information about borrowings [line items]

^[1]

Other borrowings [member]

Disclosure of detailed information about borrowings [line items]

Other borrowings [member] | Not later than one year [member]

619,007

822,152

Disclosure of detailed information about borrowings [line items]

Other borrowings [member] | Later than one year and not later than two years [member]

303,268

781,272

Disclosure of detailed information about borrowings [line items]

Other borrowings [member] | Later than two years and not later than three years [member]

104,147

17,307

Disclosure of detailed information about borrowings [line items]

Other borrowings [member] | Later than three years and not later than four years [member]

207,595

23,573

Disclosure of detailed information about borrowings [line items]

Other borrowings [member] | Later than four years and not later than five years [member]

3,997

Disclosure of detailed information about borrowings [line items]

Other borrowings [member] | Later than five years [member]

Disclosure of detailed information about borrowings [line items]

Disclosure of defined benefit plans [line items]

[1]	Includes the effect of hedge accounting.

Note 20 - Borrowings - Significant Borrowings as of Closing Date (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about borrowings [line items]
Significant borrowings as of closing date	$ 619,007	$ 822,152
Significant borrowings as of closing date [member] \| Maverick Tube Corporation and Subsidiaries One [Member]
Disclosure of detailed information about borrowings [line items]
Significant borrowings as of closing date	50,000
Significant borrowings as of closing date [member] \| Maverick Tube Corporation and Subsidiaries Two [Member]
Disclosure of detailed information about borrowings [line items]
Significant borrowings as of closing date	75,000
Significant borrowings as of closing date [member] \| Tamsa Hydril and Other One [Member]
Disclosure of detailed information about borrowings [line items]
Significant borrowings as of closing date	60,000
Significant borrowings as of closing date [member] \| Tamsa Hydril and Other Two [Member]
Disclosure of detailed information about borrowings [line items]
Significant borrowings as of closing date	80,000
Significant borrowings as of closing date [member] \| Tamsa Hydril and Other Three [Member]
Disclosure of detailed information about borrowings [line items]
Significant borrowings as of closing date	60,000
Significant borrowings as of closing date [member] \| Saudi Steel Pipe Company [member]
Disclosure of detailed information about borrowings [line items]
Significant borrowings as of closing date	$ 81,000

Note 20 - Borrowings - Weighted Average Interest Rates of Borrowings (Details)	Dec. 31, 2020	Dec. 31, 2019
Weighted average [member]
Disclosure of detailed information about borrowings [line items]
Total borrowings, weighted average interest rates	2.51%	3.18%

Note 20 - Borrowings - Borrowings by Currency and Rate (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about borrowings [line items]
Borrowings	$ 315,739	$ 40,880
Borrowings	303,268	781,272
United States of America, Dollars \| Fixed interest rate [member]
Disclosure of detailed information about borrowings [line items]
Borrowings	17,936	18,370
Borrowings	2,322	274,799
United States of America, Dollars \| Floating interest rate [member]
Disclosure of detailed information about borrowings [line items]
Borrowings	274,600
Borrowings	67,823	17,092
Saudi Arabia, Riyals \| Fixed interest rate [member]
Disclosure of detailed information about borrowings [line items]
Borrowings	20,902	16,106
Borrowings	38,750	24,797
Saudi Arabia, Riyals \| Floating interest rate [member]
Disclosure of detailed information about borrowings [line items]
Borrowings	37,776	35,666
Euro Member Countries, Euro \| Fixed interest rate [member]
Disclosure of detailed information about borrowings [line items]
Borrowings	1,828	5,108
Borrowings	3,886	3,772
Euro Member Countries, Euro \| Floating interest rate [member]
Disclosure of detailed information about borrowings [line items]
Borrowings	473	1,296
Borrowings	1,015	80
Mexico, Pesos \| Fixed interest rate [member]
Disclosure of detailed information about borrowings [line items]
Borrowings	147,997	424,964
Argentina, Pesos \| Fixed interest rate [member]
Disclosure of detailed information about borrowings [line items]
Borrowings	3,699	86
Other currency [member] \| Floating interest rate [member]
Disclosure of detailed information about borrowings [line items]
Borrowings		$ 16

Note 20 - Borrowings - Borrowings Evolution (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Borrowings [abstract]
At the beginning of the year, noncurrent	$ 40,880
At the beginning of the year, current	781,272
Translation differences, noncurrent	266
Translation differences, current	(487)
Proceeds and repayments, net, noncurrent	234,455
Proceeds and repayments, net, current	(478,913)
Interests Accrued less payments, noncurrent	426
Interests Accrued less payments, current	(12,016)
Reclassifications, noncurrent	(12,940)
Reclassifications, current	12,940
Increase due to Business Combinations, noncurrent	52,652
Increase due to Business Combinations, current	398
Overdrafts variation, noncurrent
Overdrafts variation, current	74
At the end of the year, noncurrent	315,739
At the end of the year, current	$ 303,268

Note 21 - Deferred Income Tax (Details Textual) $ in Millions	Dec. 31, 2020 USD ($)
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Recognized tax losses expiring within one year, percentage	0.00%
Recognized tax losses expiring in two to five years, percentage	1.70%
Recognized tax losses expiring in more than five years, percentage	98.30%
Unused tax losses for which no deferred tax asset recognised	$ 173.7
Unused tax losses for which no deferred tax asset recognised, percent expiring in less than one year	4.60%
Unused tax losses for which no deferred tax asset recognised, percent expiring between two and five years	17.10%
Unused tax losses for which no deferred tax asset recognised, percent expiring in more than five years	78.30%
UNITED STATES
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Deferred tax assets related to taxable losses of subsidiaries	$ 438.8

Note 21 - Deferred Income Tax - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
At the beginning of the year	$ 111,302	$ 197,433
Translation differences	6,854	1,100
Increase due to business combinations	32,099	10,847
Charged to other comprehensive income	(3,146)	(838)
Income statement charge / (credit)	(97,898)	(97,240)
At the end of the year	49,211	111,302
Deferred tax assets, provisions and allowances [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
At the beginning of the year	(19,653)	(16,116)
Translation differences	1,804	362
Increase due to business combinations	(7,452)	(1,160)
Charged to other comprehensive income
Income statement charge / (credit)	4,093	(2,739)
At the end of the year	(21,208)	(19,653)
Deferred tax assets, inventory [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
At the beginning of the year	(93,404)	(86,585)
Translation differences	513	306
Increase due to business combinations	(24,580)	(1,413)
Charged to other comprehensive income
Income statement charge / (credit)	31,534	(5,712)
At the end of the year	(85,937)	(93,404)
Deferred tax assets, tax loss [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
At the beginning of the year	(382,832)	(396,257)
Translation differences	1,996	497
Increase due to business combinations	(33,598)	(1,172)
Charged to other comprehensive income
Income statement charge / (credit)	(65,715)	14,100
At the end of the year	(480,149)	(382,832)
Deferred tax assets, other [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
At the beginning of the year	(181,606)	(86,184)
Translation differences	644	286
Increase due to business combinations	(34,974)	(2,238)
Charged to other comprehensive income	(1,952)	(1,261)
Income statement charge / (credit)	10,930	(92,209)
At the end of the year	(206,958)	(181,606)
Deferred tax assets [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
At the beginning of the year	(677,495)	(585,142)
Translation differences	4,957	1,451
Increase due to business combinations	(100,604)	(5,983)
Charged to other comprehensive income	(1,952)	(1,261)
Income statement charge / (credit)	(19,158)	(86,560)
At the end of the year	(794,252)	(677,495)
Deferred tax liabilities, fixed assets [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
At the beginning of the year	651,339	710,995
Translation differences	1,644	(347)
Increase due to business combinations	89,306	5,621
Charged to other comprehensive income
Income statement charge / (credit)	(39,874)	(64,930)
At the end of the year	702,415	651,339
Deferred tax liabilities, inventory [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
At the beginning of the year	19,396	25,048
Translation differences
Increase due to business combinations
Charged to other comprehensive income
Income statement charge / (credit)	(4,141)	(5,652)
At the end of the year	15,255	19,396
Deferred tax liabilities, intangible and other assets [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
At the beginning of the year	118,062	46,532
Translation differences	253	(4)
Increase due to business combinations	43,397	11,209
Charged to other comprehensive income	(1,194)	423
Income statement charge / (credit)	(34,725)	59,902
At the end of the year	125,793	118,062
Deferred tab liabilities [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
At the beginning of the year	788,797	782,575
Translation differences	1,897	(351)
Increase due to business combinations	132,703	16,830
Charged to other comprehensive income	(1,194)	423
Income statement charge / (credit)	(78,740)	(10,680)
At the end of the year	$ 843,463	$ 788,797

Note 21 - Deferred Income Tax - Recovery Analysis of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Deferred tax assets to be recovered after 12 months	$ (205,590)	$ (225,680)
Deferred tax liabilities to be settled after 12 months	254,801	336,982
Later than one year [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Deferred tax assets to be recovered after 12 months	(640,603)	(538,274)
Deferred tax liabilities to be settled after 12 months	$ 840,892	$ 766,852

Note 21 - Deferred Income Tax - Net Deferred Tax Liabilities (Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Disclosure of temporary difference, unused tax losses and unused tax credits [abstract]
Deferred tax assets			$ (205,590)	$ (225,680)
Deferred tax liabilities			254,801	336,982
Net deferred tax liability (asset)	$ 49,211	$ 111,302	$ 49,211	$ 111,302
At the beginning of the year	111,302	197,433
Translation differences	6,854	1,100
Increase due to business combinations	32,099	10,847
Charged to other comprehensive income	(3,146)	(838)
Income statement charge / (credit)	(97,898)	(97,240)
At the end of the year	$ 49,211	$ 111,302

Note 22 - Other Liabilities (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of defined benefit plans [line items]
Overfunded Plan	$ 2.1	$ 4.2
Estimate of contributions expected to be paid to plan for next annual reporting period	2.8
Unfunded post-employment benefits [member]
Disclosure of defined benefit plans [line items]
Actuarial losses (gains) arising from changes in demographic assumptions, net defined benefit liability (asset)	1.6	1.3
Actuarial losses (gains) arising from changes in financial assumptions, net defined benefit liability (asset)	$ 3.8	5.7
Unfunded post-employment benefits [member] \| Actuarial assumption of discount rates [member]
Disclosure of defined benefit plans [line items]
Percentage of reasonably possible increase in actuarial assumption	1.00%
Increase (decrease) in defined benefit obligation due to reasonably possible increase in actuarial assumption	$ 7.2
Increase (decrease) in defined benefit obligation due to reasonably possible decrease in actuarial assumption	$ 6.0
Unfunded post-employment benefits [member] \| Actuarial assumption of expected rates of salary increases [member]
Disclosure of defined benefit plans [line items]
Percentage of reasonably possible increase in actuarial assumption	1.00%
Increase (decrease) in defined benefit obligation due to reasonably possible increase in actuarial assumption	$ 3.1
Increase (decrease) in defined benefit obligation due to reasonably possible decrease in actuarial assumption	2.8
Funded post-employment benefits [member]
Disclosure of defined benefit plans [line items]
Actuarial losses (gains) arising from changes in demographic assumptions, net defined benefit liability (asset)	3.7	0.4
Actuarial losses (gains) arising from changes in financial assumptions, net defined benefit liability (asset)	$ 14.3	$ 12.4
Funded post-employment benefits [member] \| Actuarial assumption of discount rates [member]
Disclosure of defined benefit plans [line items]
Percentage of reasonably possible increase in actuarial assumption	1.00%
Increase (decrease) in defined benefit obligation due to reasonably possible increase in actuarial assumption	$ 24.2
Increase (decrease) in defined benefit obligation due to reasonably possible decrease in actuarial assumption	$ 19.7
Funded post-employment benefits [member] \| Actuarial assumption of expected rates of salary increases [member]
Disclosure of defined benefit plans [line items]
Percentage of reasonably possible increase in actuarial assumption	1.00%
Increase (decrease) in defined benefit obligation due to reasonably possible increase in actuarial assumption	$ 1.9
Increase (decrease) in defined benefit obligation due to reasonably possible decrease in actuarial assumption	$ 1.7

Note 22 - Other Liabilities - Other Noncurrent Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Disclosure of Other Liabilities [Abstract]
Post-employment benefits	$ 136,811	$ 144,993
Other-long term benefits	64,928	85,473
Miscellaneous	43,896	20,917
Other non-current liabilities	$ 245,635	$ 251,383

Note 22 - Other Liabilities - Post-employment Benefits (Details) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2020

Dec. 31, 2019

Post-employment benefits

$ 136,811

$ 144,993

99,000

Unfunded post-employment benefits [member]

82,400

99,000

Disclosure of defined benefit plans [line items]

Post-employment benefits

115,774

125,573

Curtailments and settlements

125,573

97,318

Current service cost

4,796

7,978

Interest cost

6,496

5,526

(1,237)

Remeasurements

^[1]

(2,230)

7,010

(415)

(1,567)

Benefits paid from the plan

1,566

15,660

(22,955)

(9,328)

Other

4,180

2,976

Funded post-employment benefits [member]

115,774

125,573

Disclosure of defined benefit plans [line items]

Post-employment benefits

21,037

19,420

160,412

146,885

Current service cost

850

721

Interest cost

5,009

5,754

Remeasurements

^[2]

18,025

12,769

Benefits paid from the plan

2,148

4,542

(9,266)

(10,259)

Other

(869)

Present value of funded obligations

176,309

160,412

176,309

160,412

Fair value of plan assets

(157,335)

(145,160)

Liability

^[3]

$ 18,974

$ 15,252

[1]	For 2020 a loss of $1.6 million is attributable to demographic assumptions and a gain of $3.8 million to financial assumptions. For 2019 a loss of $1.3 million is attributable to demographic assumptions and a loss of $5.7 million to financial assumptions.
[2]	For 2020 a loss of $3.7 million is attributable to demographic assumptions and a loss of $14.3 million to financial assumptions.For 2019 a loss of $0.4 million is attributable to demographic assumptions and a loss of $12.4 million to financial assumptions.
[3]	In 2020 and 2019, $2.1 million and $4.2 million corresponding to a plan with a surplus balance were reclassified within other non-current assets, respectively.

Note 22 - Other Liabilities - Actuarial Assumptions (Details)	Dec. 31, 2020	Dec. 31, 2019
Bottom of range [member] \| Unfunded post-employment benefits [member]
Disclosure of defined benefit plans [line items]
Discount rate	1.00%	1.00%
Rate of compensation increase	0.00%	0.00%
Bottom of range [member] \| Funded post-employment benefits [member]
Disclosure of defined benefit plans [line items]
Discount rate	1.00%	3.00%
Rate of compensation increase	0.00%	0.00%
Top of range [member] \| Unfunded post-employment benefits [member]
Disclosure of defined benefit plans [line items]
Discount rate	7.00%	7.00%
Rate of compensation increase	3.00%	3.00%
Top of range [member] \| Funded post-employment benefits [member]
Disclosure of defined benefit plans [line items]
Discount rate	3.00%	4.00%
Rate of compensation increase	3.00%	3.00%

Note 22 - Other Liabilities - Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of defined benefit plans [line items]
Values at the beginning of the year	$ 99,000
At the end of the year	82,400	$ 99,000
Fair value of funded post-employment benefits [member]
Disclosure of defined benefit plans [line items]
Values at the beginning of the year	(145,160)	(132,438)
Translation differences	(1,729)	(4,137)
Return on plan assets	(4,411)	(5,018)
Remeasurements	(10,396)	(10,507)
Contributions paid to the plan	(5,017)	(3,589)
Benefits paid from the plan	(9,266)	(10,259)
Other	112	270
At the end of the year	(157,335)	(145,160)
Funded post-employment benefits [member]
Disclosure of defined benefit plans [line items]
Values at the beginning of the year	160,412	146,885
Translation differences	(2,148)	(4,542)
Benefits paid from the plan	(9,266)	(10,259)
Other	(869)
At the end of the year	$ 176,309	$ 160,412
Equity instruments	49.30%	49.00%
Debt instruments	46.80%	47.00%
Others	3.90%	4.00%

Note 22 - Other Liabilities - Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Disclosure of Other Liabilities [Abstract]
Payroll and social security payable	$ 175,175	$ 153,009
Miscellaneous	27,651	23,255
Other current liabilities	$ 202,826	$ 176,264

Note 23 - Non-current allowances and provisions - Liabilities (Details) - Provision for non-current liabilities [member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of other provisions [line items]
Values at the beginning of the year	$ 54,599	$ 36,089
Translation differences	(5,739)	(1,571)
Increase due to business combinations	26,542
Additional provisions	478	19,904
Reclassifications	557	5,641
Used	(3,219)	(5,464)
Values at the end of the year	$ 73,218	$ 54,599

Note 24 - Current allowances and provisions - Deducted From Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Allowance for doubtful accounts - trade receivables [member]
Disclosure of other provisions [line items]
Values at the beginning of the year	$ (48,782)	$ (66,535)
Translation differences	(37)	9
Increase due to business combinations	(1,930)	(1,788)
(Additional) / reversals allowances		16,256
Used	1,717	3,276
(Additional) allowances	(4,644)
Values at the end of the year	(53,676)	(48,782)
Allowance for other doubtful accounts - other receivables [member]
Disclosure of other provisions [line items]
Values at the beginning of the year	(4,892)	(6,784)
Translation differences	801	88
Increase due to business combinations
(Additional) / reversals allowances		1,239
Used	1,437	565
(Additional) allowances	(1,263)
Values at the end of the year	(3,917)	(4,892)
Allowance for inventory obsolescence [member]
Disclosure of other provisions [line items]
Values at the beginning of the year	(217,717)	(209,796)
Translation differences	1,560	794
Increase due to business combinations	(76,776)	(10,761)
(Additional) / reversals allowances		(29,138)
Used	65,107	31,184
(Additional) allowances	(35,809)
Values at the end of the year	$ (263,635)	$ (217,717)

Note 24 - Current allowances and provisions - Liabilities (Details) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2020

Dec. 31, 2019

Sales risks [member]

Disclosure of other provisions [line items]

$ 5,867

$ 6,814

(5)

(28)

Additional / (reversals) provisions

116

505

9,728

11,880

Reclassifications

Used

(13,911)

(13,304)

Miscellaneous other provisions [member]

1,795

5,867

Disclosure of other provisions [line items]

^[1]

11,150

17,469

^[1]

(975)

(570)

Additional / (reversals) provisions

^[1]

398

8,000

^[1]

1,751

(3,219)

Reclassifications

^[1]

(557)

(5,641)

Used

^[1]

(1,283)

(4,889)

Provision for current liabilities [member]

^[1]

10,484

11,150

Disclosure of other provisions [line items]

17,017

24,283

(980)

(598)

Additional / (reversals) provisions

514

8,505

11,479

8,661

Reclassifications

(557)

(5,641)

Used

(15,194)

(18,193)

HYDRIL COMPANY and subsidiaries [member]

$ 12,279

$ 17,017

[1]	Other claims and contingencies mainly include lawsuits and other legal proceedings, including employee, tax and environmental-related claims.

Note 25 - Derivative Financial Instruments - Net Fair Values (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Disclosure of information about credit exposures designated as measured at fair value through profit or loss [line items]
Derivatives with positive fair values	$ 11,449	$ 19,929
Derivatives with negative fair values	(3,217)	(1,814)
Total	8,232	18,115
Derivatives hedging borrowings and investments [member]
Disclosure of information about credit exposures designated as measured at fair value through profit or loss [line items]
Derivatives with positive fair values	10,119	19,000
Derivatives with negative fair values	(2,250)
Other derivatives [member]
Disclosure of information about credit exposures designated as measured at fair value through profit or loss [line items]
Derivatives with positive fair values	1,330	929
Derivatives with negative fair values	$ (967)	$ (1,814)

Note 25 - Derivative Financial Instruments - Foreign Exchange Derivative Contracts and Hedge Accounting (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about hedging instruments [line items]
Fair value of derivatives	$ 8,232	$ 18,115
Hedge accounting reserve	(4,800)	2,600
Cash flow hedges [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of derivatives	8,232	18,115
Hedge accounting reserve	(4,771)	2,591	$ (916)
Foreign exchange contract, purchase currency MXN, sell currency USD [member] \| Cash flow hedges [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of derivatives	9,838	18,999
Hedge accounting reserve	156	404
Foreign exchange contract, purchase currency USD, sell currency MXN [member] \| Cash flow hedges [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of derivatives	(5)	(576)
Hedge accounting reserve
Foreign exchange contract, purchase currency USD, sell currency EUR [member] \| Cash flow hedges [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of derivatives	(1,969)
Hedge accounting reserve	5
Foreign exchange contract, purchase currency EUR, sell currency USD [member] \| Cash flow hedges [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of derivatives	543	588
Hedge accounting reserve
Foreign exchange contract, purchase currency JPY, sell currency USD [member] \| Cash flow hedges [member] \| Term, One [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of derivatives		(190)
Hedge accounting reserve
Foreign exchange contract, purchase currency JPY, sell currency USD [member] \| Cash flow hedges [member] \| Term Two [Member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of derivatives	94
Hedge accounting reserve	(4,958)	2,149
Foreign exchange contract, purchase currency USD, sell currency BRL [member] \| Cash flow hedges [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of derivatives	412	(234)
Hedge accounting reserve	85
Foreign exchange contract, purchase currency USD, sell currency KWD [member] \| Cash flow hedges [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of derivatives	(246)	103
Hedge accounting reserve	(59)	38
Foreign exchange contract, purchase currency USD, sell currency CAD [member] \| Cash flow hedges [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of derivatives		(200)
Hedge accounting reserve
Foreign exchange contract, purchase currency USD, sell currency COP [member] \| Cash flow hedges [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of derivatives		(345)
Hedge accounting reserve
Foreign exchange contract, purchase currency USD, sell currency CNY [member] \| Cash flow hedges [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of derivatives	(482)	(167)
Hedge accounting reserve
Foreign exchange contract, Other [member] \| Cash flow hedges [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of derivatives	47	137
Hedge accounting reserve

Note 25 - Derivative Financial Instruments - Hedge Reserve Evolution (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about hedging instruments [line items]
Hedge accounting reserve	$ 2,600
Hedge accounting reserve	(4,800)	$ 2,600
Cash flow hedges [member]
Disclosure of detailed information about hedging instruments [line items]
Hedge accounting reserve	2,591	(916)
Movements	(7,362)	3,507
Hedge accounting reserve	(4,771)	2,591
Foreign exchange derivatives contracts [member] \| Cash flow hedges [member]
Disclosure of detailed information about hedging instruments [line items]
Hedge accounting reserve	2,591	(916)
Movements	(7,362)	3,507
Hedge accounting reserve	$ (4,771)	$ 2,591

Note 26 - Contingencies, Commitments and Restrictions On the Distribution of Profits (Details Textual) $ / shares in Units, R$ in Thousands, $ in Thousands, € in Millions			12 Months Ended
	Oct. 09, 2018 USD ($)	Sep. 01, 2013 $ / shares shares	Dec. 31, 2020 USD ($)	Dec. 31, 2020 EUR (€)	Dec. 31, 2020 BRL (R$)	Dec. 31, 2020 USD ($)	Nov. 19, 2020 BRL (R$)	Nov. 19, 2020 USD ($)	Sep. 28, 2020 BRL (R$)	Sep. 28, 2020 USD ($)	Dec. 31, 2019	Oct. 10, 2018 BRL (R$)
Contingencies, commitments and restrictions on the distribution of profits
Term of supply contract (Year)			9 years
Performance Guarantees Issued						$ 2,500,000
Techgen s.a. [member]
Contingencies, commitments and restrictions on the distribution of profits
Proportion of ownership interest in associate			22.00%
Proportion of corporate guarantee covering obligations				22.00%	22.00%	22.00%					22.00%
Confab [member] \| Chubb [member]
Contingencies, commitments and restrictions on the distribution of profits
Payments for settlement	$ 3,500
Settlement, amount ordered to pay \| R$												R$ 13,100
Confab [member] \| Veracel Celulose S.A. [member]
Contingencies, commitments and restrictions on the distribution of profits
Settlement, amount ordered to pay, insurance deductible					R$ 69,900	$ 13,500
Settlement, amount ordered to pay, damages					59,900	11,500
Tribunal de Contas da Uniao [member] \| Legal proceedings contingent liability [member]
Contingencies, commitments and restrictions on the distribution of profits
Estimated financial effect of contingent liabilities							R$ 30,600	$ 5,900
Tribunal de Contas da Uniao [member] \| Legal proceedings contingent liability [member] \| Top of range [member]
Contingencies, commitments and restrictions on the distribution of profits
Alleged overprice that will be reduced amount									R$ 9,000	$ 1,700
Tribunal de Contas da Uniao [member] \| Legal proceedings contingent liability [member] \| Bottom of range [member]
Contingencies, commitments and restrictions on the distribution of profits
Alleged overprice that will be reduced amount									R$ 401	$ 77
Transportadora de Gas del Norte S.A. [member]
Contingencies, commitments and restrictions on the distribution of profits
Term of supply contract (Year)			14 years
Purchase commitments						16,800
Transportadora de Gas del Norte S.A. [member] \| Techgen s.a. [member]
Contingencies, commitments and restrictions on the distribution of profits
Term of supply contract (Year)			25 years
Praxair S.A. [member]
Contingencies, commitments and restrictions on the distribution of profits
Purchase commitments						31,000
Graftech [member]
Contingencies, commitments and restrictions on the distribution of profits
Purchase commitments						10,900
Air Liquide Mexico S. de R.L. de C.V. [member]
Contingencies, commitments and restrictions on the distribution of profits
Purchase commitments						19,000
CONFAB INDUSTRIAL S.A. and subsidiaries [member] \| Tax contingent liability [member] \| BRAZIL
Contingencies, commitments and restrictions on the distribution of profits
Estimated financial effect of contingent liabilities					R$ 57,200	$ 11,000
Fine imposed, percentage of allegedly undue credits				75.00%	75.00%	75.00%
CONFAB INDUSTRIAL S.A. and subsidiaries [member] \| Companhia Siderúrgica Nacional [member]
Contingencies, commitments and restrictions on the distribution of profits
Tag-along tender offer to non-controlling interests, percentage		80.00%
Tag-along tender offer to non-controlling interests (in BRL per share) \| $ / shares		$ 28.8
Tag-along tender offer to non-controlling interests, shares (in shares) \| shares		182,609,851
Tag-along tender offer to non-controlling interests, contingent liability		17.90%
DALMINE S.p.A. [member] \| Tax contingent liability related to fiscal year 2014 [member] \| ITALY
Contingencies, commitments and restrictions on the distribution of profits
Estimated financial effect of contingent liabilities				€ 25.7		$ 31,600
DALMINE S.p.A. [member] \| Tax contingent liability related to fiscal year 2014, principal [member] \| ITALY
Contingencies, commitments and restrictions on the distribution of profits
Estimated financial effect of contingent liabilities				20.7		25,500
DALMINE S.p.A. [member] \| Tax contingent liability related to fiscal year 2014, interest and penalties [member] \| ITALY
Contingencies, commitments and restrictions on the distribution of profits
Estimated financial effect of contingent liabilities				5.0		6,100
DALMINE S.p.A. [member] \| Tax contingent liability related to fiscal year 2015 [member] \| ITALY
Contingencies, commitments and restrictions on the distribution of profits
Estimated financial effect of contingent liabilities				10.5		12,900
DALMINE S.p.A. [member] \| Tax contingent liability related to fiscal year 2015, principal [member] \| ITALY
Contingencies, commitments and restrictions on the distribution of profits
Estimated financial effect of contingent liabilities				8.1		10,000
DALMINE S.p.A. [member] \| Tax contingent liability related to fiscal year 2015, interest and penalties [member] \| ITALY
Contingencies, commitments and restrictions on the distribution of profits
Estimated financial effect of contingent liabilities				€ 2.4		2,900
IPSCO Tubulars, Inc. \| Commitments and guarantees
Contingencies, commitments and restrictions on the distribution of profits
Estimated financial effect of contingent liabilities						498,300
Master distribution agreement, term (Year)			6 years
Master distribution agreement, term, available extension (Month)			12 months
Penalties imposed			$ 0
IPSCO Tubulars, Inc. \| Product liability litigation
Contingencies, commitments and restrictions on the distribution of profits
Estimated financial effect of contingent liabilities						17,600
IPSCO Tubulars, Inc. \| Product liability litigation \| Legal proceedings contingent liability [member]
Contingencies, commitments and restrictions on the distribution of profits
Estimated financial effect of contingent liabilities						15,000
TENARIS BAY CITY, INC. [member] \| Nucor Steel Memphis Inc. [member]
Contingencies, commitments and restrictions on the distribution of profits
Term of supply contract (Year)			3 years
Purchase commitments						$ 113,400
Purchase commitments percentage to be made				75.00%	75.00%	75.00%

Note 27 - Foreign exchange control measures in Argentina (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
ARGENTINA \| Subsidiaries [member]
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]
Percentage of entity's net equity	8.00%
Percentage of entity's revenue	12.00%
Argentine Peso / U.S. dollar foreign exchange risk [member]
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]
Currency exposure / functional currency	$ 39,561	$ 95,811
Argentine Peso / U.S. dollar foreign exchange risk [member] \| Argentina, Pesos
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [line items]
Currency exposure / functional currency	$ 39,600

Note 28 - Cash Flow Disclosures - Cash Flow Disclosures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Cash Flow [Abstract]
Inventories	$ 828,796	$ 311,459	$ (176,443)
Receivables and prepayments and Current tax assets	74,877	(34,368)	30,144
Trade receivables	409,163	428,326	(517,579)
Other liabilities	(34,871)	(18,295)	(22,984)
Customer advances	(34,388)	16,844	5,976
Trade payables	(184,442)	(180,857)	(57,066)
Increase (decrease) in working capital	1,059,135	523,109	(737,952)
Income tax accruals less payments
Tax accrued	23,150	202,452	229,207
Taxes paid	(140,364)	(395,869)	(170,713)
Adjustments for income tax expense	(117,214)	(193,417)	58,494
Interest accruals less payments, net
Interest accrued	8,627	(4,616)	(2,914)
Interest received	19,613	30,890	40,613
Interest paid	(28,778)	(30,655)	(31,548)
Interest income (expense)	$ (538)	$ (4,381)	$ 6,151

Note 29 - Related Party Transactions (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of transactions between related parties [line items]
Total number of shares issued (in shares)	1,180,536,830	1,180,536,830	1,180,536,830
Key management personnel compensation, short-term employee benefits	$ 27.4	$ 33.7	$ 33.7
Key management personnel compensation, share-based payment	$ 5.0	$ 4.8	$ 5.6
San Faustin S.A. [member]
Disclosure of transactions between related parties [line items]
Total number of shares issued (in shares)	713,605,187
Proportion of ownership interest in associate	60.45%
Key management personnel of entity or parent [member]
Disclosure of transactions between related parties [line items]
Proportion of ownership interest in associate	0.08%
Units issued, related party transactions (in shares)	522,000	468,000	558,000

Note 29 - Related Party Transactions - Transactions Carried Out With Related Parties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of transactions between related parties [line items]
Revenue, related party transactions	$ 49,304	$ 100,555	$ 168,545
Purchases of goods and services, related party transactions	122,489	290,271	407,545
Amounts receivable (payable), related party transactions	55,944	63,136
Finance lease liabilities from non-consolidated parties	(2,042)	(2,064)
Finance lease liabilities from other related parties	(810)
Financial debt, related parties	(2,852)	(2,064)
Associates [member]
Disclosure of transactions between related parties [line items]
Sales of goods to related parties	20,183	20,577	23,709
Sales of services to related parties	5,829	5,620	7,641
Purchases of goods to related parties	84,485	174,588	245,186
Purchases of services to related parties	6,979	9,404	9,556
Receivables from non-consolidated parties	78,721	78,884
Payables to non-consolidated parties	(24,914)	(19,100)
Other related parties [member]
Disclosure of transactions between related parties [line items]
Sales of goods to related parties	18,243	69,972	131,548
Sales of services to related parties	5,049	4,386	5,647
Purchases of goods to related parties	12,892	51,765	106,624
Purchases of services to related parties	18,133	54,514	$ 46,179
Receivables from non-consolidated parties	4,447	10,400
Payables to non-consolidated parties	$ (2,310)	$ (7,048)

Note 30 - Fees Paid to the Company's Principal Accountant - Fees Accrued for Professional Services (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Additional information [abstract]
Audit fees	$ 3,781	$ 3,846	$ 3,841
Audit-related fees	134	50	43
Tax fees	102	7
All other fees		1	7
Total	$ 4,017	$ 3,904	$ 3,891

Note 31 - Principal Subsidiaries (Details Textual)	12 Months Ended
Note 31 - Principal Subsidiaries (Details Textual)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
HYDRIL COMPANY and subsidiaries [member]
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary		100.00%
Technical Drilling & Production Services Nigeria. Ltd [member]
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary		80.00%	80.00%
Tenaris Supply Chain S.A. [member]
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	97.50%
Tubular Technical Services and Pipe Coaters [member]
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	40.00%
Amaja Tubular Services Limited [member]
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	49.00%
Tubular Services Angola Lda. [member]
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	49.00%
Tenaris Baogang Baotou Steel Pipes Ltd [member]
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	60.00%

Note 31 - Principal Subsidiaries - Percentage of Ownership of Each Controlled Company (Details)

12 Months Ended

Dec. 31, 2020

Dec. 31, 2019

Dec. 31, 2018

CANADA | ALGOMA TUBES INC. [member]

100.00%

CANADA | PRUDENTIAL STEEL LTD. [member]

^[1]

100.00%

CANADA | TENARIS GLOBAL SERVICES (CANADA) INC. [member]

^[1],[2]

100.00%

BRAZIL | CONFAB INDUSTRIAL S.A. and subsidiaries [member]

^[1]

100.00%

ITALY | DALMINE S.p.A. [member]

^[1]

100.00%

UNITED STATES | HYDRIL COMPANY and subsidiaries [member]

^[1]

100.00%

UNITED STATES | IPSCO TUBULARS INC. and subsidiaries [member]

^[1],[3]

100.00%

UNITED STATES | MAVERICK TUBE CORPORATION and subsidiaries [member]

^[1]

100.00%

UNITED STATES | TENARIS BAY CITY, INC. [member]

^[1]

100.00%

UNITED STATES | TENARIS GLOBAL SERVICES (U.S.A.) CORPORATION [member]

^[1]

100.00%

KAZAKHSTAN | Kazakhstan Pipe Threaders Limited [member]

^[1]

100.00%

JAPAN | NKKTUBES [member]

^[1]

100.00%

INDONESIA | PT SEAMLESS PIPE INDONESIA JAYA [member]

^[1]

51.00%

ROMANIA | S.C. SILCOTUB S.A. [member]

^[1]

89.00%

SAUDI ARABIA | Saudi Steel Pipe Company [member]

^[1]

100.00%

ARGENTINA | SIAT SOCIEDAD ANONIMA [member]

^[1]

48.00%

ARGENTINA | SIDERCA S.A.I.C. and subsidiaries [member]

^[1]

100.00%

PORTUGAL | TALTA—TRADING E MARKETING SOCIEDADE UNIPESSOAL LDA. [member]

^[1]

100.00%

NETHERLANDS | TENARIS CONNECTIONS BV [member]

^[1]

100.00%

NETHERLANDS | TENARIS INVESTMENTS (NL) B.V. and subsidiaries [member]

^[1]

100.00%

URUGUAY | TENARIS FINANCIAL SERVICES S.A. [member]

^[1]

100.00%

URUGUAY | TENARIS GLOBAL SERVICES S.A. and subsidiaries [member]

^[1]

100.00%

UNITED KINGDOM | TENARIS GLOBAL SERVICES (UK) LTD [member]

^[1],[4]

100.00%

LUXEMBOURG | TENARIS INVESTMENTS S.àr.l. [member]

^[1]

100.00%

Colombia | TENARIS TUBOCARIBE LTDA. [member]

^[1]

100.00%

MEXICO | TUBOS DE ACERO DE MEXICO S.A. [member]

^[1]

100.00%