CONSOLIDATED CONDENSED INTERIM FINANCIAL STATEMENTS For the six-month period ended June 30, 2026

-

TENARIS S.A.

26, Boulevard Royal - 4th Floor L-2449 - Luxembourg R.C.S. Luxembourg: B 85203

CONSOLIDATED CONDENSED

INTERIM FINANCIAL STATEMENTS

For the six-month period ended June 30, 202 6

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated 1

CONSOLIDATED CONDENSED INTERIM INCOME STATEMENT S

Three -month period ended June 30, Six-month period ended

June 30,

2026 2025 2026 2025 Notes (Unaudited) (Unaudited) Net sales 3 2,966,626 3,085,672 6,067,084 6,007,884 Cost of sales 4 (1,981,966) (2,013,639) (4,032,289) (3,934,494) Gross profit 984,660 1,072,033 2,034,795 2,073,390 Selling, general and administrative expenses 5 (484,107) (483,633) (950,698) (940,698) Other operating income 6 2,791 4,317 9,231 16,105 Other operating expenses 6 (9,342) (9,983) (15,462) (16,150) Operating income 494,002 582,734 1,077,866 1,132,647 Finance income 7 52,970 63,669 117,739 142,113 Finance cost 7 (11,906) (9,712) (23,570) (21,457) Other financial results, net 7 (8,956) (22,294) (11,662) (53,735) Income before equity in earnings of non -consolidated companies and income tax 526,110 614,397 1,160,373 1,199,568 Equity in earnings of non -consolidated companies 8 47,963 32,651 81,339 46,686 Income before income tax 574,073 647,048 1,241,712 1,246,254 Income tax 9 (81,938) (105,342) (185,419) (186,684) Income for the period 492,135 541,706 1,056,293 1,059,570

Attributable to:

Shareholders' equity 477,137 531,323 1,017,838 1,038,254 Non-controlling interests 14,998 10,383 38,455 21,316 492,135 541,706 1,056,293 1,059,570 Earnings per share attributable to shareholders' equity during the period:

Weighted average number of outstanding ordinary shares (thousands) (*) 1,009,640 1,068,721 1,009,956 1,072,974

Basic and diluted earnings per share (U.S. dollars per share) 0.47 0.50 1.01 0.97 Basic and diluted earnings per ADS (U.S. dollars per ADS) (**) 0.95 0.99 2.02 1.94

(*) Number of outstanding shares as of June 30, 2026, and 2025, w as 1,009,639,756 and 1,058,900,662, respectively.

(**) Each ADS equals two shares.

The accompanying notes are an integral part of these Consolidated Condense d Interim Financial Statements.

These Consolidated Condensed Interim Financial Statements should be read in conjunction with our audited Consolidated Financial Statements and notes for the fis cal year ended December 31, 2025.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated 2

CONSOLIDATED CONDENSED INTERIM STATEMENT S OF OTHER COMPREHENSIVE INCOME

Three -month period ended June 30, Six-month period ended

June 30,

2026 2025 2026 2025

(Unaudited) (Unaudited)

Income for the period 492,135 541,706 1,056,293 1,059,570 Items that may be subsequently reclassified to profit or loss:

Currency translation adjustment (5,883) 90,003 (31,454) 134,752 Change in value of cash flow hedges and instruments at fair value 2,803 (17,069) (19,024) (37,664) Income tax relating to components of other comprehensive income (1,590) 5,782 25,553 21,805 From participation in non -consolidated companies:

- Currency translation adjustment (43) 9,948 1,097 23,530

- Changes in the value of cash flow hedges and instruments at fair value, net of income tax 1,408 (434) 5,425 2,550 (3,305) 88,230 (18,403) 144,973 Items that will not be reclassified to profit or loss:

Remeasurements of post-employment benefit obligations 615 380 615 367 Income tax on remeasurements of post -employment benefit obligations (229) 129 (362) 129 Remeasurements of post -employment benefit obligations of non-

consolidated companies, net of income tax (105) 128 (6) 26 281 637 247 522 Other comprehensive (loss) income for the period (3,024) 88,867 (18,156) 145,495 Total comprehensive income for the period 489,111 630,573 1,038,137 1,205,065

Attributable to:

Shareholders' equity 474,193 619,176 1,000,064 1,182,252 Non-controlling interests 14,918 11,397 38,073 22,813 489,111 630,573 1,038,137 1,205,065

The accompanying notes are an integral part of these Consolidated Condensed Interim Financial Statements.

These Consolidated Condensed Interim Financial Statements should be read in conjunction with our audited Consolidated Financi al Statements and notes for the fiscal year ended December 31, 2025.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated 3

CONSOLIDATED CONDENSED INTERIM STATEMENT S OF FINANCIAL POSITION

At June 30, 2026 At December 31, 2025

Notes (Unaudited)

ASSETS

Non-current assets

Property, plant and equipment, net 11 6,147,589 6,205,082 Intangible assets, net 12 1,355,974 1,357,116 Right -of-use assets, net 13 147,129 144,557 Investments in non -consolidated companies 17 1,619,204 1,561,212 Other investments NC 14 1,089,080 758,085 Deferred tax assets 813,183 834,168 Receivables, net 116,296 11,288,455 139,211 10,999,431

Current assets

Inventories, net 3,716,159 3,602,058 Receivables and prepayments, net 168,406 268,798 Current tax assets 383,643 364,640 Contract assets 29,537 35,264 Trade receivables, net 1,927,777 1,920,840 Derivative financial instruments CA 15 14,570 1,875 Other investments C 14 2,225,725 2,306,760 Cash and cash equivalents 14 557,057 9,022,874 572,647 9,072,882 Total assets 20,311,329 20,072,313

EQUITY

Shareholders' equity 16,962,791 16,599,191 Non-controlling interests 255,872 229,877 Total equity 17,218,663 16,829,068

LIABILITIES

Non-current liabilities

Borrowings 357 368 Lease liabilities 13 98,226 94,903 Derivative financial instruments NCL 15 - 207 Deferred tax liabilities 395,239 442,248 Other liabilities 321,569 310,707 Provisions 59,429 874,820 48,418 896,851

Current liabilities

Borrowings 301,534 305,354 Lease liabilities 13 46,833 48,346 Derivative financial instruments CL 15 5,363 14,123 Current tax liabilities 270,253 386,586 Other liabilities 443,284 377,088 Provisions 155,029 173,152 Customer advances 129,925 168,832 Trade payables 865,625 2,217,846 872,913 2,346,394 Total liabilities 3,092,666 3,243,245 Total equity and liabilities 20,311,329 20,072,313

The accompanying notes are an integral part of these Consolidated Condensed Interim Financial Statements.

These Consolidated Condensed Interim Financial Statements should be read in conjunction with our audited Consolidated Financi al Statements and notes for the fiscal year ended December 31, 2025.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated 4

CONSOLIDATED CONDENSED INTERIM STATEMENT S OF CHANGES IN EQUITY

Shareholders' equity

Share

Capital (1) Treasury Shares

(2) Legal

Reserves Currency

Translation

Adjustment Other

Reserves (4) Retained Earnings (5) Total Non-controlling

interests Total

(Unaudited)

Balance at December 31, 2025 1,071,995 (1,125,131) 107,199 (952,833) (384,072) 17,882,033 16,599,191 229,877 16,829,068 Income for the period - - - - - 1,017,838 1,017,838 38,455 1,056,293 Currency translation adjustment - - - (31,078) - - (31,078) (376) (31,454) Remeasurements of post -employment benefit obligations, net of taxes - - - - 272 - 272 (19) 253 Change in value of instruments at fair value through other comprehensive income and cash flow hedges, net of taxes - - - - 6,516 - 6,516 13 6,529 Other comprehensive income of non -consolidated companies - - - 1,097 5,419 - 6,516 - 6,516 Other comprehensive (loss) income for the period - - - (29,981) 12,207 - (17,774) (382) (18,156) Total comprehensive income (loss) for the period - - - (29,981) 12,207 1,017,838 1,000,064 38,073 1,038,137 Repurchase of own shares (2) - (89,562) - - - - (89,562) - (89,562) Cancellation of own shares (3) (62,355) 1,214,693 (6,235) - - (1,146,103) - - -

Changes in share buyback program liability - - - - 58,888 - 58,888 - 58,888 Distribution of dividends - - - - - (605,790) (605,790) (12,078) (617,868) Balance at June 30, 2026 1,009,640 - 100,964 (982,814) (312,977) 17,147,978 16,962,791 255,872 17,218,663

(1) The Company has an authorized share capital of a single class of 2.5 billion shares having a nominal value of USD1.00 per sha re. As of June 30, 2026, th ere were 1,009,639,756 shares issued. All issued shares are fully paid.

(2) As of June 30, 2026, the Company held no treasury shares. For further information, see Note 23.

(3) On May 12, 2026 , the extraordinary general meeting of shareholders approved the cancelation of 62,355,174 ordinary shares held in treasury by the Company and the corresponding reduction of the issued share capital of the Company and, accordingly, the legal reserve was proportionally reduced.

(4) 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 in financial instruments measured at fair value through other comprehensive income and the changes in the share buyback program liability .

(5) The restrictions to the distribution of profits and payment of dividends according to Luxembourg Law are disclosed in note 18 .

The accompanying notes are an integral part of these Consolidated Condensed Interim Financial Statements.

These Consolidated Condensed Interim Financial Statements should be read in conjunction with our audited Consolidated Financi al Statements and notes for the fiscal year ended December 31, 2025.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated 5

Shareholders' equity

Share

Capital (1) Treasury Shares (2) Legal

Reserves Share

Premium Currency

Translation

Adjustment Other

Reserves

(4) Retained

Earnings (5) Total Non-

controlling

interests Total

(Unaudited)

Balance at December 31, 2024 1,162,758 (1,355,651) 116,276 609,733 (1,110,803) (570,986) 17,741,930 16,593,257 220,578 16,813,835 Income for the period - - - - - - 1,038,254 1,038,254 21,316 1,059,570 Currency translation adjustment - - - - 133,275 - - 133,275 1,477 134,752 Remeasurements of post -employment benefit obligations, net of taxes - - - - - 476 - 476 20 496 Change in value of instruments at fair value through other comprehensive income and cash flow hedges, net of taxes - - - - - (15,859) - (15,859) - (15,859) Other comprehensive income of non -consolidated companies - - - - 23,530 2,576 - 26,106 - 26,106 Other comprehensive income (loss) for the period - - - - 156,805 (12,807) - 143,998 1,497 145,495 Total comprehensive income (loss) for the period - - - - 156,805 (12,807) 1,038,254 1,182,252 22,813 1,205,065 Transfers of remeasurements of post -employment benefit obligations, net of taxes to retained earnings - - - - - (565) 565 - - -

Repurchase of own shares (2) - (471,678) - - - - - (471,678) - (471,678) Cancellation of own shares (3) (90,763) 1,590,585 (9,077) (609,733) - - (881,012) - - -

Changes in share buyback program liability - - - - - (119,972) - (119,972) - (119,972) Acquisition and other changes in non -controlling interests - - - - - - - - (780) (780) Distribution of dividends - - - - - - (600,317) (600,317) (31,494) (631,811) Balance at June 30, 2025 1,071,995 (236,744) 107,199 - (953,998) (704,330) 17,299,420 16,583,542 211,117 16,794,659

(1) The Company had an authorized share capital of a single class of 2.5 billion shares having a nominal value of USD1.00 per share. As of June 30, 2025, t here were 1,071,994,930 shares issued. All issued shares are fully paid.

(2) As of June 30, 2025 , the Company held 13,094,268 treasury shares, and there were 1,058,900,662 outstanding shares. For more information, see note 23 .

(3) On May 6, 2025 , the extraordinary general meeting of shareholders approved the cancelation of 90,762,598 ordinary shares held in treasury by the Company and the corresponding reduction of the issued share capital of the Company and, accordingly, the legal reserve was proportionally reduced.

(4) 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 in financial instruments measured at fair value through other comprehensive income and the changes in the share buyback program liability.

(5) The restrictions to the distribution of profits and payment of dividends according to Luxembourg Law are disclosed in note 18 .

The accompanying notes are an integral part of these Consolidated Condensed Interim Financial Statements.

These Consolidated Condensed Interim Financial Statements should be read in conjunction with our audited Consolidated Financi al Statements and notes for the fiscal year ended December 31, 2025.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

6

CONSOLIDATED CONDENSED INTERIM STATEMENT S OF CASH FLOWS

Six-month period ended June 30, Notes 2026 2025

(Unaudited)

Cash flows from operating activities Income for the period 1,056,293 1,059,570

Adjustments for:

Depreciation and amortization 11, 12 & 13 306,769 296,408 Provision for the ongoing litigation related to the acquisition of participation in Usiminas 6 & 18 15,641 18,527 Income tax accruals less payments 21 (98,440) (90,793) Equity in earnings of non -consolidated companies 8 (81,339) (46,686) Interest accruals less payments/collections, net 21 17,083 (13,039) Changes in provisions (22,753) (1,765) Changes in working capital (*) 21 (83,720) 250,316 Others, including net foreign exchange 25,636 21,609 Net cash provided by operating activities 1,135,170 1,494,147

Cash flows from investing activities Capital expenditures 11 & 12 (235,935) (309,292) Changes in advances to suppliers of property, plant and equipment 9,983 (5,853) Cash decrease due to deconsolidation of subsidiaries (**) - (1,848) Acquisition of subsidiaries, net of cash acquired (***) 24 (4,507) -

Loan to joint ventures 17 - (1,359) Repayment of loan by joint ventures 17 68,788 -

Proceeds from disposal of property, plant and equipment and intangible assets 1,011 57,729 Dividends received from non -consolidated companies 17 29,863 41,348 Changes in investments in securities (286,375) (131,337) Net cash used in investing activities (417,172) (350,612)

Cash flows from financing activities Dividends paid 10 (605,790) (600,317) Dividends paid to non -controlling interest in subsidiaries (1,232) (27,264) Acquisition of treasury shares 23 (89,562) (473,932) Payments of lease liabilities 13 (33,663) (30,047) Proceeds from borrowings 356,232 476,443 Repayments of borrowings (359,034) (574,956) Net cash used in financing activities (733,049) (1,230,073) Decrease in cash and cash equivalents (15,051) (86,538)

Movement in cash and cash equivalents At the beginning of the period 572,444 660,798 Effect of exchange rate changes (410) (2,768) Decrease in cash and cash equivalents (15,051) (86,538) At June 30, 556,983 571,492

At June 30, Cash and cash equivalents 2026 2025 Cash and bank deposits 557,057 572,289 Bank overdrafts (74) (797)

556,983 571,492

(*) Changes in working capital do not include non- cash movements due to the variations in the exchange rates used by subsidiaries with functional currencies different from the U.S. dollar for an amount of $ 13.1 million for the six-month period ended June 30, 2026, and $ (36.7) million for the six-

month period ended June 30, 2025.

(**) For the six -month period ended June 30, 2025 , related to the deconsolidation of Amaja Tubular Services Limited.

(***) For the six -month period ended June 30, 2026 , mainly related to the a cquisition of the oilfield division of AllTorque . For more information see note 24.

The accompanying notes are an integral part of these Consolidated Condensed Interim Financial Statements.

These Consolidated Condensed Interim Financial Statements should be read in conjunction with our audited Consolidated Financi al Statements and notes for the fiscal year ended December 31, 2025.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

7

NOTES TO THE CONSOLIDATED CONDENSED INTERIM FINANCIAL STATEMENTS

1 General information 2 Accounting policies and basis of presentation 3 Segment information 4 Cost of sales 5 Selling, general and administrative expenses 6 Other operating income (expense), net 7 Financial results 8 Equity in earnings of non -consolidated companies 9 Income tax 10 Dividend distribution 11 Property, plant and equipment, net 12 Intangible assets, net 13 Right -of-use assets, net and lease liabilities 14 Cash and cash equivalents and other investments 15 Derivative financial instruments 16 Category of financial instruments and classification within the fair value hierarchy 17 Investments in non-consolidated companies 18 Contingencies, commitments and restrictions on the distribution of profits 19 Tariffs on steel and other imports 20 Foreign exchange control measures in Argentina 21 Cash flow disclosures 22 Related party transactions 23 Share buyback programs 24 Business combinations 25 Agreement for acquisition of Artrom Steel Tubes S.A.

26 Middle East war 27 Events after the reporting period

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

8

NOTES TO THE CONSOLIDATED CONDENSED INTERIM FINANCIAL STATEMENTS

1 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 Condensed Interim Financial Statements to “Tenaris ” refer to Tenaris S.A. and its consolidated subsidiaries.

A list of the Company’s principal subsidiaries is included in note 33 to the Company’s audited Consolidated Financial Statements for the year ended December 31, 202 5.

The Company’s shares trade on the Italian Stock Exchange and the Mexican Stock Exchange, and its American Depositary Securities (“ADS”) trade on the New York Stock Exchange.

These Consolidated Condensed Interim Financial Statements were approved for issuance by the Company’ s Board of Directors on August 5, 202 6.

2 Accounting policies and basis of presentation These Consolidated Condensed Interim Financial Statements have been prepared in accordance with IAS 34, “Interim Financial Reporting” as issued by the International Accounting Standards Board (“IASB”) and as adopted by the European Union (“EU”) . The accounting policies used in the preparation of these Consolidated Condensed Interim Financial Statements are consistent with those used in the audited Consolidated Financial Statements for the year ended December 31, 202 5. These Consolidated Condensed Interim Financial Statements should be read in conjunction with the audited Consolidated Financial Statements for the year ended December 31, 202 5, which have been prepared in accordance with IFRS Accounting Standards as issued by the IASB and in conformity with IFRS as adopted by the EU.

The preparation of Consolidated Condensed Interim Financial Statements requires management to make certain accounting estimates and assumptions that might affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities as of the reporting dates, and the reported amounts of revenues and expenses for the reported periods. Actual results may differ from these estimates . The main areas involving significan t estimates or judgments are impairment of long- lived assets ; impairment of investments in associates ; income taxes -including recoverability of deferred tax assets -; allowance for obsolescence of inventory; contingencies; allowance for trade receivables; post -

employment and other long -term benefits ; business combinations; useful lives of property, plant and equipment and other long- lived assets and fair value estimation of certain financial instruments . During the period there were no material changes in the significant accounting estimates and judgements .

Tenaris carefully assesses the potential impact of climate change and energy transition on its business and the risks to its markets and its tangible and intangible assets and adapts its business strategy accordingly. These events did not impact materially management judgments and estimates used in the preparation of these Consolidated Condensed Interim Financial Statements. For further information, see note 3 6 to our audited Consolidated Financial Statements for the year ended December 31, 2025 .

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

There were no significant changes in valuation techniques during the period and there have been no changes in any risk management policies sinc e the year ended December 31, 202 5.

If necessary, comparative amounts have been reclassified to conform to changes in presentation in the current period.

None of the accounting pronouncements applicable after December 31, 2025 , and as of the date of these Consolidated Condensed Interim Financial Statements had a material effect on the Company’s financial condition or result of its operations.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

9 3 Segment information

Reportable operating segment s

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

Six-month period ended June 30, 2026 - (Unaudited) Tubes Other Total Management view - operating income 932 64 996 Difference in cost of sales 63 Differences in selling, general and administrative expenses 19 IFRS - operating income 1,078 Financial income (expense), net 82 Income before equity in earnings of non -consolidated companies and income tax 1,160 Equity in earnings of non -consolidated companies 81 Income before income tax 1,242 Net sales 5,734 333 6,067 Depreciation and amortization 296 11 307

Six-month period ended June 30, 2025 - (Unaudited) Tubes Other Total Management view - operating income 1,055 68 1,123 Difference in cost of sales 17 Differences in selling, general and administrative expenses (5) Differences in other operating income (expenses) and others (2) IFRS - operating income 1,133 Financial income (expense), net 67 Income before equity in earnings of non -consolidated companies and income tax 1,200 Equity in earnings of non -consolidated companies 47 Income before income tax 1,246 Net sales 5,686 322 6,008 Depreciation and amortization 287 9 296

There are no material differences between IFRS and management view s in total revenues .

The differences between operating income under the IFRS and management views are mainly related to the cost of goods sold, reflecting the effect of raw materials prices variations on the valuation of the replacement cost considered for management view compared to IFRS cost calculated at historical cost on a FIFO basis, and other timing differences. For more information see note II.C “Segment information” in the Company’s audited Consolidated Financial Statements for the year ended December 31, 2025.

The main differences in net income under the IFRS and management views arise from the impact of functional currencies on financial result, deferred income taxes as well as the equity in earnings of non- consolidated companies .

Geographical information

Six-month period ended June 30,

2026 2025

(Unaudited)

Net sales

North America 3,050,377 2,725,465 South America 1,205,114 1,255,208 Europe 528,440 473,972 Asia Pacific, Middle East and Africa 1,283,153 1,553,239 Total 6,067,084 6,007,884 Allocation of net sales to geographical information is based on the final destination of the products sold.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

10 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, Argentina, Canada, Saudi Arabia, Mexico and United Arab Emirates .

The Company’s largest customer accounted for approximately 10% of revenues from third parties in the six -month period ended June 30, 2026, while no single customer accounted for more than 10% of revenues from third parties in the corresponding period of 2025. These revenues were attributable to the Company’s Tubes segment.

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. In the six-month periods ended June 30, 202 6, and 2025 , revenues related to governmental institutions represent ed approximately 23% and 26% , respectively .

Tubes segment revenues by market:

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

Six-month period ended June 30, Revenues Tubes 2026 2025

(Unaudited)

Oil & Gas 5,079 5,090 Oil & Gas processing plants 242 273 Industrial, Power & Others 413 323 Total 5,734 5,686

The table above includes revenues from services performed on third party tubes of $199.5 million and $210.8 million for the six -month periods ended June 30, 202 6, and 2025 , respectively.

4 Cost of sales

Six-month period ended June 30,

2026 2025

(Unaudited)

Inventories at the beginning of the period 3,602,058 3,709,942 Changes in inventories due to business combinations (*) 471 -

Decrease in inventory due to deconsolidation of subsidiaries (**) - (43) Plus: Charges of the period Raw materials, energy, consumables and other 2,371,916 2,147,144 Services and fees 191,747 142,809 Labor cost 754,953 699,194 Depreciation of property, plant and equipment 235,690 227,573 Amortization of intangible assets 8,433 6,639 Depreciation of right -of-use assets 20,236 18,166 Maintenance expenses 205,490 180,139 Allowance for obsolescence (14,759) 25,348 Taxes 262,678 131,956 Other 109,535 132,164

4,146,390 3,711,089

Less: Inventories at the end of the period (3,716,159) (3,486,537)

4,032,289 3,934,494

(*) For the six -month period ended June 30, 2026 , related to the purchase price allocation arising from the acquisition of a scrap processing business in Beaver Falls, Pennsylvania. For more information see note 24.

(**) For the six -month period ended June 30, 2025 , related to the deconsolidation of Amaja Tubular Services Limited.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

11 5 Selling, general and administrative expenses

Six-month period ended June 30,

2026 2025

(Unaudited)

Services and fees 95,746 94,908 Labor cost 365,876 343,847 Depreciation of property, plant and equipment 12,706 12,528 Amortization of intangible assets 15,062 19,043 Depreciation of right -of-use assets 14,642 12,459 Freights and other selling expenses 319,416 332,417 Provisions for contingencies 24,162 5,952 Allowances for doubtful accounts 20 11,083 Taxes 57,975 61,753 Other 45,093 46,708

950,698 940,698

6 Other operating income (expense), net

Six-month period ended June 30,

2026 2025

(Unaudited)

(i) Other operating income Results from sundry assets 3,994 4,700 Net rents 1,906 2,136 Allowance for doubtful receivables recovery 642 -

Other income 2,689 9,269

9,231 16,105

(ii) Other operating expenses Contributions to welfare projects and non -profit organizations (7,147) (9,593) Allowance for doubtful receivables - (222) Provision for the ongoing litigation related to the acquisition of participation in Usiminas (8,315) (6,335)

(15,462) (16,150)

Other operating income and expenses, net (6,231) (45)

Provision for the ongoing litigation related to the acquisition of participation in Usiminas: this item relates to the provision described in note 18, without reflecting any net foreign exchange result associated thereto.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

12 7 Financial results

Six-month period ended June 30,

2026 2025

(Unaudited)

Interest income 114,394 129,757 Net result on changes in FV of financial assets at FVTPL 3,345 12,356 Finance income 117,739 142,113 Finance cost (23,570) (21,457) Net foreign exchange transactions results 13,603 (30,984) Net foreign exchange derivatives contracts results (25,150) (6,671) Others (115) (16,080) Other financial results, net (11,662) (53,735) Net financial results 82,507 66,921

Interest i ncome: For the six -month period ended June 30, 202 6, includes $20.0 million of interest related to instruments carried at FVTPL and includes $37.0 million of interest related to instruments carried at FVTOCI.

For the six -month period ended June 30, 202 5, includes $16.0 million of interest related to instruments carried at FVTPL and includes $ 47.4 million of interest related to instruments carried at FVTOCI.

Other: For the six -month period ended June 30, 2025, includes a loss of approximately $1 5.8 million related to fee s paid in connection with a collection involving the Company’s Mexican subsidiary.

8 Equity in earnings of non -consolidated companies

Six-month period ended June 30,

2026 2025

(Unaudited)

Earnings from non-consolidated companies 81,339 46,686

81,339 46,686

Earnings from non- consolidated companies: These results are mainly derived from our investment s in Ternium and Usiminas.

9 Income tax

Six-month period ended June 30,

2026 2025

(Unaudited)

Current tax (212,097) (221,455) Deferred tax 26,678 34,771

(185,419) (186,684)

Tenaris is within the scope of the OECD Pillar Two model rules. Pillar Two legislation was adopted in Luxemb ourg, the jurisdiction in which the C ompany is incorporated, a nd came into effect as from January 1, 2024. T enaris applies the exception regarding the recognition and disclosure of deferred tax assets and liabilities related to Pillar Two income taxes, as provided in the amendments to IAS 12 issued in May 2023.

In the six -month periods ended June 30, 2026 and 2025 , Tenaris recognized an estimate d current tax expense related to Pillar Two , amounting to $ 6.8 million and $11.3 million , respectively .

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

13 10 Dividend distribution

On May 12, 202 6, the Company’s shareholders approved an annual dividend of $0.89 per outstanding share ($ 1.78 per ADS) , which represents an aggregate sum of approximately US$0.9 billion, and which include s the interim dividend of $0.29 per outstanding share ($ 0.58 per ADS) paid on November 26, 2025. The remaining balance, amounting to $0. 60 per outstanding share ($ 1.20 per ADS), which represents approximately $0.6 billion, was paid on May 2 0, 2026 .

On May 6, 2025, the Company’s shareholders approved an annual dividend of $0.83 per outstanding share ($ 1.66 per ADS) , which represent ed an aggregate sum of approximately US$0.9 billion, and which included the interim dividend of $0.27 per outstanding share ($ 0.54 per ADS) paid on November 20, 2024. The remaining balance, amounting to $0.56 per outstanding share ($ 1.12 per ADS), which represented approximately $0.6 billion, was paid on May 21, 2025.

11 Property, plant and equipment, net

2026 2025

(Unaudited)

Six-month period ended June 30, Opening net book amount 6,205,082 6,121,471 Currency translation adjustment (18,361) 70,647 Changes due to business combinations (*) 395 -

Additions 215,692 279,044 Disposals / Consumptions (**) (8,056) (63,486) Transfers / Reclassifications 1,233 1,053 Decrease due to deconsolidation (***) - (374) Depreciation charge (248,396) (240,101) At June 30, 6,147,589 6,168,254

(*) For the six -month period ended June 30, 2026, related to the acquisition of the oilfield division of AllTorque and the purchase price allocation arising from the acquisition of a scrap processing business in Beaver Falls, Pennsylvania. For more information see note 24.

(**) For the six -month period ended June 30, 2025 , includes the unwinding of certain land plots in Saudi Arabia.

(***) For the six -month period ended June 30, 2025 , related to the deconsolidation of Amaja Tubular Services Limited .

The Company’s Brazilian subsidiary , Confab Industrial S.A. (“Confab”) , holds certain real estate assets, with a carrying value of $32.4 million, that are subject to a judicial mortgage aimed at securing the indemnification potentially payable to Companhia Siderúrgica Nacional (“CSN") under a lawsuit brough by CSN against Confab and other related companies. The litigation is currently pending, and no amount is currently owed by Confab. See note 18 “Contingencies, commitments and restrictions on the distribution of profits -

Contingencies - CSN claims relating to the January 2012 acquisition of Usiminas ” to these Consolidated Condensed Interim Financial Statements .

The Company’s Saudi Arabian subsidiary, Global Pipe Company (“GPC”), holds certain assets with a carrying value of $37.7 million that are pledged as security for current borrowings. Tenaris holds an indirect participation of 27.6% in GPC through its subsidiary, Saudi Steel Pipe Company (“SSPC”).

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

14 12 Intangible assets, net

2026 2025

(Unaudited)

Six-month period ended June 30, Opening net book amount 1,357,116 1,357,749 Currency translation adjustment (286) 1,000 Changes due to business combinations (*) 3,642 -

Additions 20,243 30,248 Disposals (13) -

Transfers / Reclassifications (1,233) (1,053) Amortization charge (23,495) (25,682) At June 30, 1,355,974 1,362,262

(*) For the six -month period ended June 30, 2026 , related to the acquisition of the oilfield division of AllTorque and the purchase price allocation arising from the acquisition of a scrap processing business in Beaver Falls, Pennsylvania . For more information see note 24.

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

Right -of-use assets , net evolution

2026 2025

(Unaudited)

Six-month period ended June 30, Opening net book amount 144,557 148,868 Currency translation adjustment (276) 1,090 Additions 39,497 33,419 Disposals (1,771) (5,555) Depreciation charge (34,878) (30,625) At June 30, 147,129 147,197

Right -of-use assets, net by underlying category

At June 30, At December 31,

2026 2025

(Unaudited)

Land and civil buildings 41,767 35,604 Industrial buildings, plant and production equipment 76,096 80,851 Vehicles, furniture and fixtures 26,819 26,633 Others 2,447 1,469

147,129 144,557

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

Lease liabilities evolution

2026 2025

(Unaudited)

Six-month period ended June 30, Opening net book amount 143,249 144,926 Translation differences (1,031) 5,200 Additions 37,051 33,308 Cancellations (1,648) (5,844) Repayments of lease liabilities including interests (*) (35,806) (32,616) Interest accrued 3,244 3,113 At June 30, 145,059 148,087

(*) For the six -month period ended June 30, 2026, includes repayments of $33.7 million in capital and $ 2.1 million of interest. For the six-month period ended June 30, 2025 , includes repayments of $30.0 million in capital and $ 2.6 million of interest .

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

15 As of June 30, 202 6, the amount of remaining payments with maturit ies of less than 1 year, between 2 and 5 years and more than 5 years was approximately 32% , 45% and 23% , respectively.

As of December 31, 202 5, the amount of remaining payments with maturit ies of less than 1 year, between 2 and 5 years and more than 5 years wa s approximately 34% , 41%, and 25% , respectively.

14 Cash and cash equivalents and other investments

At June 30, At December 31,

2026 2025

Cash and cash equivalents (Unaudited) Cash at banks 266,589 142,476 Liquidity funds 135,732 258,919 Short -term investments 154,736 171,252

557,057 572,647

Other investments - current Bonds and other fixed income 1,173,638 1,069,393 Fixed income (time -deposit, zero coupon bonds, commercial papers) 713,088 827,476 Fund investments 338,999 409,891

2,225,725 2,306,760

Other investments - non-current Bonds and other fixed income 996,875 655,867 Fixed income (time -deposit, zero coupon bonds, commercial papers) 85,317 95,090 Others 6,888 7,128

1,089,080 758,085

As of June 30, 202 6, Other Investments – current includes financial assets subject to lending agreement with financial institutions for a total amount of $ 101.7 million . Under applicable contractual terms, Tenaris retains substantially all the risks and rewards of ownership of the financial assets and has not received any collateral in connection to them. The fee received is recognized as a gain within Financ e income , as interest income.

15 Derivative financial instruments

At June 30, At December 31,

2026 2025

(Unaudited)

Derivatives hedging borrowings and investments 1,265 -

Other derivatives 13,305 1,875 Contracts with positive fair values 14,570 1,875

Derivatives hedging borrowings and investments - 2,669 Other derivatives 5,363 11,661 Contracts with negative fair values 5,363 14,330

Other d erivatives include contracts which are designated to hedge positions other than borrowings and investments.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

16 16 Category of financial instruments and classification within the fair value hierarchy

The following table illustrates the three hierarchical levels for valuing financial instruments at fair value and those measured at amortized cost as of June 30, 2026, and December 31, 2025.

Carrying

amount Measurement Categories At Fair Value June 30, 2026 - (Unaudited) Amortized Cost Fair Value Level 1 Level 2 Level 3

Assets

Cash and cash equivalents 557,057 421,325 135,732 135,732 - -

Other investments 2,225,725 713,088 1,512,637 1,512,637 - -

Fixed Income (time -deposit, zero coupon bonds, commercial papers) 713,088 713,088 - - - -

Bonds and other fixed income 1,173,638 - 1,173,638 1,173,638 - -

Fund investments 338,999 - 338,999 338,999 - -

Derivative financial instruments 14,570 - 14,570 - 14,570 -

Other Investments Non -current 1,089,080 85,317 1,003,763 996,875 - 6,888 Bonds and other fixed income 996,875 - 996,875 996,875 - -

Fixed income (time -deposit, zero coupon bonds, commercial papers) 85,317 85,317 - - - -

Other investments 6,888 - 6,888 - - 6,888 Trade receivables 1,927,777 1,927,777 - - - -

Receivables C and NC 314,237 68,619 - - - -

Other receivables 68,619 68,619 - - - -

Other receivables (non -financial) 245,618 - - - - -

Total 3,216,126 2,666,702 2,645,244 14,570 6,888

Liabilities

Borrowings C and NC 301,891 301,891 - - - -

Trade payables 865,625 865,625 - - - -

Other liabilities C and NC 764,853 16,459 - - - -

Other liabilities 16,459 16,459 - - - -

Other liabilities (non -financial) 748,394 - - - - -

Lease Liabilities C and NC 145,059 145,059 - - - -

Derivative financial instruments 5,363 - 5,363 - 5,363 -

Total 1,329,034 5,363 - 5,363 -

Carrying

amount Measurement Categories At Fair Value December 31, 2025 Amortized Cost Fair Value Level 1 Level 2 Level 3

Assets

Cash and cash equivalents 572,647 313,728 258,919 258,919 - -

Other investments 2,306,760 827,476 1,479,284 1,479,284 - -

Fixed income (time -deposit, zero coupon bonds, commercial papers) 827,476 827,476 - - - -

Bonds and other fixed income 1,069,393 - 1,069,393 1,069,393 - -

Fund investments 409,891 - 409,891 409,891 - -

Derivative financial instruments 1,875 - 1,875 - 1,875 -

Other Investments Non-current 758,085 95,090 662,995 655,867 - 7,128 Bonds and other fixed income 655,867 - 655,867 655,867 - -

Fixed income (time -deposit, zero coupon bonds, commercial papers) 95,090 95,090 - - - -

Other investments 7,128 - 7,128 - - 7,128 Trade receivables 1,920,840 1,920,840 - - - -

Receivables C and NC 443,273 190,124 - - - -

Other receivables 190,124 190,124 - - - -

Other receivables (non -financial) 253,149 - - - - -

Total 3,347,258 2,403,073 2,394,070 1,875 7,128

Liabilities

Borrowings C and NC 305,722 305,722 - - - -

Trade payables 872,913 872,913 - - - -

Other liabilities C and NC 687,795 6,227 58,888 - - 58,888 Other liabilities (*) 65,115 6,227 58,888 - - 58,888 Other liabilities (non -financial) 622,680 - - - - -

Lease liabilities C and NC 143,249 143,249 - - - -

Derivative financial instruments 14,330 - 14,330 - 14,330 -

Total 1,328,111 73,218 - 14,330 58,888

(*) Includes liability related to the share buyback program.

Certain non- financial assets and liabilities were included in the above table s to allow reconciliation with the Consolidated Condensed Interim Statement s of Financial Position.

Due to their short time nature, the carrying amounts of trade receivables, trade payables, other financial receivables, other financial liabilities and other investments are considered to be similar to their fair values.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

17 There were no transfers between l evels during the period.

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, th e 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.

The fair value of all outstanding derivatives is determined by 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.

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 management assumptions which reflect the Company’s best estimate on how market participants would price the asset or liability at measurement date. As of December 31, 2025 , main balances in this level include d a liability related to the shares to be settled under the share buyback program which was concluded during the six -month period ended June 30, 2026. Unobservable inputs related to this balance consider assumptions regarding average purchase prices of previous periods, and management's past experience related to the conclusion of the share buyback program itself. A reasonable change in the inputs used would have not affect ed the fair value of the liability materially.

Borrowings are comprised primarily of fixed rate debt and variable rate debt with a short -term portion where interest has already been fixed. They are classified under other financial liabilities and measured at their amortized cost. Tenaris estimates that the fair value (level 2) of its main borrowings is approximately 99.4% of its carrying amount including interests accrued as of June 30, 202 6, as compare d with 99.5% as of December 31, 202 5. Fair values were calculated using standard valuation techniques for floating rate instruments and comparable market rates for discounting cash flows.

17 Investments in non -consolidated companies

This note supplements and should be read in conjunction with note 1 4 “Investments in non- consolidated companies” to the Company’s audited Consolidated Financial Statements for the year ended December 31, 2025.

Six-month period ended June 30,

2026 2025

(Unaudited)

At the beginning of the period 1,561,212 1,543,657 Translation differences 1,097 23,530 Equity in earnings of non -consolidated companies 81,339 46,686 Dividends and distributions received (29,863) (41,348) Increase in equity reserves and others 5,419 2,576 At the end of the period 1,619,204 1,575,101

Dividends and distributions received: During the six -month period ended June 30, 2026 and 2025 , $29.9 million and $41.3 million were respectively collected. These dividends are derived from our investment in Ternium.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

18

a) Ternium

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

As of June 30, 2026 , the closing price of Ternium’s ADSs as quoted on the New York Stock Exchange was $ 42.70 per ADS, giving Tenaris’s ownership stake a market value of approximately $ 980.9 million. A s of that date , the carrying value of Tenaris’s ownership stake in Ternium, based on Ternium’s Consolidated Condensed Interim Financial Statements, was approximately $1,416.6 million.

The Company reviews its participation in Ternium whenever events or circumstances indicate that the asset’s carrying amount may not be recoverable. As of June 30, 2026 , the Company concluded that the carrying amount of its investment in Ternium did not exceed its recoverable value.

b) Usiminas

Usinas Siderúrgicas de Minas Gerais (“Usiminas ”) is a Brazilian producer of high- quality flat steel products used in the energy, automotive and other industries.

As of June 30, 2026 , the closing price of the Usiminas’ ordinary and preferred shares, as quoted on the B3 - Brasil Bolsa Balcão S.A ., was BRL 7.64 ($1.48) and BRL 8.45 ($1.63), respectively, giving Tenaris’s ownership stake a market value of approximately $72.2 million. As of that date, the carrying value of Tenaris’s ownership stake in Usiminas was approximately $118.4 million.

The Company reviews its participation in Usiminas whenever events or circumstances indicate that the asset’s carrying amount may not be recoverable. As of June 30, 2026 , the Company concluded that the carrying amount of its investment in Usiminas did not exceed its recoverable value.

c) Techgen

Techgen S.A. de C.V. (“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, with a power capacity of 900 MW. As of June 30, 2026 , Tenaris held 22% of Techgen’s share capital, and its affiliates, Ternium and Tecpetrol Internacional S.L. (a wholly -owned subsidiary of San Faustin S.A. (“San Faustin”) , the controlling shareholder of both Tenaris and Ternium), beneficially owned 48% and 30% , respectively. As of June 30, 202 6, the carrying value of Tenaris’s ownership stake in Techgen was approximately $80.0 million.

Techgen entered into certain transportation capacity agreements and an agreement for the purchase of clean energy certificates. As of June 30, 2026 , Tenaris’s exposure under these agreements amounted to $ 31.6 million and $15.9 million , respectively.

On February 18, 2026, Techgen fully repaid the syndicated loan incurred in February 2019 with several banks to refinance indebtedness, resulting in the release or termination of the guarantees covering Techgen's obligations thereunder, including the Mexican security trust (covering shares, assets, accounts and contract rights), account pledges, direct agreements and the stand- by letters of credit issued for the account of Techgen’s sponsors covering debt service in proportion to their respective participations in Techgen.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

19 18 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 i ndemnity. 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. Accor dingly, 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 ny 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 incurre d 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, depending on the likelihood of occurrence, in some of such cases has accrued a provision for such loss but believes that publication of this information on a case -by-case basis would seriously prejudice 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 Condensed Interim 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 Condensed Interim Financial Statements. In addition, Tenaris is subject to other legal proceedings, none of which is believed to be material.

 CSN claims relating to the January 2012 acquisition of Usiminas The Company is a party to a longstanding lawsuit filed in Brazil by Companhia Siderúrgica Nacional (“CSN”), and various entities affiliated with CSN against the Company’s Brazilian subsidiary Confab and three subsidiaries of Ternium, all of whic h compose the T/T Group under the Usiminas shareholders agreement. The entities named in the CSN law suit had acquired participations in Usiminas 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 sought 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 ordin ary shares of Usiminas not belonging to Usiminas’ control group. Confab’s share in the offer would be 17.9%.

On September 23, 2013, the first instance court dismissed the CSN lawsuit, and on February 8, 2017, the Court of A ppeals maintained the understanding of the first instance court. On August 18, 2017, CSN filed an appeal to the Superior Court of Justice (“SCJ”) seeking the review and reversal of the decision issued by the Court of Appeals. On September 10, 2019, the SCJ declared CSN’s appeal admissible. On March 7, 2023, the SCJ, by majority vote, rejected CSN’s appeal.

CSN made several submissions in connection with the SCJ March 7, 2023 decision, including a motion for clarification that challenged the merits of the SCJ decision. Decisions at the SCJ are adopted by majority vote. At an October 17, 2023 session, two just ices of the SCJ voted in favor of remanding the case to the first instance for it to be retried following production and assessment of the new evidence, and two justices of the SCJ voted, without requiring any further evidence, in favor of granting CSN’s m otion for clarification and reversing the March 7, 2023 decision that rejected CSN’s appeal; because the fifth member of SCJ excused himself from voting, a justice from another panel at the SCJ was summoned to produce the tie-breaking vote. On June 18, 2024, the SCJ completed its voting on CSN’s motion for clarification and reversed, by majority vote, its March 7, 2023 decision, and resolved that Confab and the three subsidiaries of Ternium should pay CSN an indemnification in connection with the acquisition by the T/T Group of a participation in Usiminas in January 2012, with CSN being allowed to retain ownership of the Usiminas ordinary shares it currently owns.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

20 On August 1, 2024, Confab and the other T/T Group entities filed a motion for clarification against the SCJ decision and, subsequently, CSN filed its reply. On December 6, 2024, the SCJ rejected this motion for clarification, confirming the obligation of C onfab and the other T/T Group entities to pay indemnification in connection with the 2012 acquisition of the participations in Usiminas. Notwithstanding the foregoing, the SCJ unanimously resolved to modify the applicable monetary adjustment mechanism and to cap the applicable attorney’s fees, thereby lowering the aggregate amount that would be payable if CSN ultimately prevails in this claim. Based on such SCJ decision, assuming monetary adjustment through June 30, 202 6, and attorney’s fees in the amount of BRL 5 million, the revised aggregate amount potentially payable by Confab if CSN finally prevails on its claims, would be of approximately BRL 675.7 million (approximately $130.5 million at the BRL/$ rate as of such date).

The Company continues to believe that all of CSN's claims and allegations are unsupported and without merit, as confirmed by several opinions of Brazilian legal counsel, two decisions issued by the Brazilian securities regulator in February 2012 a nd Decemb er 2016, the first and second instance court decisions and the March 7, 2023 SCJ decision referred to above, and that in connection with the Usiminas acquisition the T/T Group was not required either to launch a tender offer or to pay indemnification to CS N. Accordingly, on February 10, 2025, Confab and the other T/T Group entities filed a request for extraordinary appeal against the SCJ decisions that ordered an indemnification payment, seeking their review and reversal by the Supreme Federal Tribunal. On September 10, 2025, the Vice -President of the SCJ, without examining the merits, denied leave to proceed with the extraordinary appeal as to certain arguments and ruled it inadmissible as to certain others, and on October 2, 2025, Confab and the other T/T Group entities filed an internal appeal for the special court of the SCJ to reconsider the denial of leave to proceed and a concurrent appeal against the inadmissibility ruling for the Supreme Federal Tribunal to consider admissibility of the extraordinary appeal directly. On November 26, 2025, the special court of the SCJ rejected Confab and the other T/T Group entities' internal appeal. The Supreme Federal Tribunal has not yet ruled on the admissibility of the extraordinary appeal. The Company cannot pred ict the ultimate resolution on the matter.

 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 dama ges 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 wit h 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 Ve racel 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 vio lation 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, the court subsequently homologated the above -mentioned settlement and, accordingly, the claim was finalized.

 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 BRL 127.7 million (approximately $24 .7 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 fo r damages arising from lost profits, the court award would appear to include BRL 109.5 million (approximately $2 1.2 million) of damages arising therefrom. Confab has additional defence arguments in respect of a claim for lost profits. After an appeal agains t the first instance court decision, the court resolved in June 2022 that it lacked jurisdiction to decide on the appeal, which was re -allocated to another court. On August 26, 2024, the court issued a decision rejecting certain procedural objections and ordering that new expert evidence be produced. As a result, the trial was redirected to the first instance court for new technical evidence to be produced by a new expert. On August 11, 2025, Confab filed an appeal with the SCJ against the ruling on the additional expert evidence , and on June 12, 2026, the challenged decision was upheld and the case records

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

21 were sent to the Superior Court of Justice . At this stage, the Company cannot predict the outcome of the claim or the amount or range of loss in case of an unfavourable outcome.

 Petrobras -related proceedings and claims

Upon learning of certain government investigations as to 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 Brasile iro S.A. (“Petrobras”) and whether any such payments were intended to benefit the Company’s Brazilian subsidiary Confab, the Audit Committee of the Company's Board of Directors engaged external counsel in connection with the Company’s review of these matte rs. 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, conducted, with the assistance of external counsel, an internal investigation, and found no ev idence corroborating any involvement by the Company or its directors, officers or employees in respect of improper payments. An internal investigation commissioned by Petrobras also found no evidence that Confab obtained any unfair commercial benefit or advantage from Petrobras in return for payments, including improperly obtained contracts. On June 2, 2022, the Company resolved the investigation by the SEC, and the DOJ informed that it had closed its parallel inquiry without taking action. Under the settle ment with the SEC, the Company neither admits nor denies the SEC’s findings and on June 24, 2022, paid $53.1 million in disgorgement and prejudgment interest and $25 million for a civil penalty to conclude the matter.

In July 2019, the Company learned that the public prosecutors’ office of Milan, Italy, had completed a preliminary investigation into the same 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 was not a party to the proceedings. On March 22, 2022, upon completion of the evidentiary phase of the trial, the acting prosecutor requested the first -instance court in Milan in charge of the case to impose sanctions on the Company’s Chairman and Chief Executive Officer, on the other two board members, and on San Faustin. On May 26, 2022, the first -instance court dismissed the case brought by the public prosecutor against the defendants for lack of jurisdiction and stated that the cri minal proceeding should not have been initiated. On February 22, 2024, the court of appeals referred the case to the court of cassa tion, which, on May 23, 2024, confirmed the decision of the first -instance court and closed the case.

In June 2020, 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. On December 11, 2024, the Confab executives were acquitted. The acquittal has already been appealed, so the criminal proceedings continue to be underway. Neither the Company nor Confab is a party to these criminal proceedings.

In addition, Petrobras and the Brazilian public prosecutors filed civil claims for alleged damages arising from the same event against, among others, Confab and the Confab executives named in the criminal proceedings referred to above.

The plaintiffs also seek that Confab be prohibited from contracting with, or receiving benefits or exemptions from, the Brazilian state for an unspecified term. Confab became aware of these civil claims in September 2022 and filed its defenc e in February 2025, among other things, requesting the suspension of the case until a final decision is made on the jurisdiction and the dismissal on the merits of the claims made by Petrobras and the public prosecutors. As of June 30, 2026 , the aggregate amount of these claims was estimated at BRL 208.6 million (or approximately $ 40.3 million). Confab believes these claims do not address either the defence arguments or the evidence available to the plaintiffs in Brazil and presented in other jurisdictions and is vigorously contesting them. Based on the advice of legal counsel, the Company cannot predict the outcome of these civil proceedings at this stage.

In late March 2024, the Company became aware of a resolution of Brazil’s General Controllers Office (“

Controladoria -

Geral da União” , or GCO ), which opened administrative responsibility proceedings against Confab and other non- Tenaris affiliates and formed an investigative commission charged with investigating purported irregularities. Potential outcomes of an adverse GCO decision include a de claration of ineligibility for contracting with the Brazilian state for up to six years.

Confab received notice in Fe bruary 2025 and believes that the GCO’s allegations do not address either the defenc e arguments or the evidence available to the plaintiffs in Brazil and presented in other jurisdictions. On April 7, 2025, Confab filed its defence and contested the allegations. On September 12, 2025, Confab opened discussions with GCO towards seeking a resolution of the matter, and such discussions are ongoing. Based on the advice of legal counsel, the Company cannot predict the outcome of these administrative proceedings a t this stage.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

22  U.S. patent infringement litigation

Tenaris Coiled Tubes, LLC (“ TCT”), a U.S. subsidiary of the Company, was sued in 2017 by its competitor Global Tubing, alleging defamatory conduct by TCT and seeking a declaration that certain Global Tubing products do not infringe patents held by TCT. TCT counterclaimed that certain Glo bal Tubing products did infringe patents held by TCT, and Global Tubing has since sought to invalidate such patents. On December 13, 2019, Global Tubing filed an amended complaint (including the Company as defendant), alleging, among other things, that TCT and the Company had misled the patent office. On March 20, 2023, the judge granted summary judgment in favor of Global Tubing, concluding that the patents at issue are unenforceable due to inequitable conduct during the patent prosecution process. TCT appealed this judgment, and Global Tubing appealed a previous ruling of the judge. Global Tubing also filed a brief seeking to recover attorneys’ fees, without specifying the amount of those fees. On February 26, 2026, the Federal Circuit issued an opinion re versing the finding of inequitable conduct by TCT, and reversing the lower court’s dismissal of Global Tubing ’s antitrust claim. As a practical matter, both issues will return to the lower court to eventually be resolved in a jury trial ; a mediation in the case has been scheduled for August 28, 2026, and trial is scheduled to take place in April 2027 . Although it is not possible to predict the final outcome of this matter, the Company believes that any potential losses arising from this case will not be material.

 U.S. antidumping duties

On October 26, 2021, the U.S. Department of Commerce (“DOC”) initiated antidumping duty investigations of oil country tubular goods (“OCTG”) from Argentina, Mexico, and Russia. After the DOC issued affirmative preliminary and final antidumping determinations with respect to imports from Argentina, Mexico and Russia on November 14, 2022, the International Trade Commission determined that the imports under investigation caused injury to the U.S. OCTG industry. Tenaris and other parties appealed the agency 's determinations from the investigation to the Court of International Trade, and, with respect to certain claims, to the Court of Appeals for the Federal Circuit. In addition, in response to a request from the Gov ernment of Argentina, the World Trade Organization (“WTO”) established a panel of experts to consider whether the DOC’s antidumping order applicable to Argentina is consistent with the international obligations of the United States.

As a result of the investigations, Tenaris was required to pay antidumping duty deposits (at a rate of 78.30% for imports from Argentina and 44.93% for imports from Mexico) until such time the imports were reviewed by the DOC to determine whether final dut ies were necessary for the specific period under review. Tenaris paid such deposits for the first review period (which ran from May 11, 2022, through October 31, 2023) and for subsequent review periods until the final determinations by the DOC discussed be low were published. The amount of such deposits was reflected in Tenaris’s costs.

On June 6, 2025, the DOC issued a final determination with respect to imports from Argentina that occurred during the first review period, announcing a final antidumping duty rate of 6.76% for imports by Tenaris. This lower rate (reduced from 78.30%) became the deposit rate for Tenaris’s imports from Argentina as from June 12, 2025. No appeal was filed against the DOC’s final determination and, accordingly, the DOC instructed the customs authorities to liquidate the corresponding refunds at the assessment r ate of Tenaris’s imports from Argentina for the first review period, with such instructions becoming effective on August 4, 2025. The resulting gain (including interest) up to end of 2025 was recognized in the Consolidated Financial Statements for the year ended December 31, 2025. During March 2026, Tenaris collected these refunds . While the second review period (which ran from November 1, 2023, through October 31, 2024) was rescinded, the DOC has initiated its review of the third review period (which ran f rom November 1, 2024, through October 31, 2025) for imports from Argentina.

On September 5, 2025, the DOC issued its final determination for imports from Mexico that occurred during the first review period, announcing a final rate of 26.10%. This lower rate (reduced from 44.93%) became the deposit rate for Tenaris’s imports from M exico as from September 15, 2025. Both petitioners and Tenaris appealed this determination.

As a result, the DOC has not instructed the customs authorities to liquidate these entries and will not do so while the appeals are ongoing. On May 13, 2026, the DO C issued a preliminary determination for the second review period for imports from Mexico , assessing a preliminary antidumping duty rate of 1.62% . The final determination is expected to be issued between September and November 2026. The DOC has initiated its review of the third review period for imports from Mexico.

As a result of these periodic reviews, the deposit rates on future imports can change, and the antidumping duty deposits paid on imports during the relevant review period may be either returned to Tenaris (in whole or in part) or increased.

In an audit report issued by an audit team of the U.S. Customs and Border Protection (“CBP”), CBP concluded that Tenaris should have paid antidumping duties on imports of mechanical and other pipe, which CBP believes to be subject

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

23 to the antidumping orders on OCTG from Argentina and Mexico. CBP’s audit report calculated loss of revenue to the United States of approximately $49.6 million for years 2022, 2023 and 2024. However, CBP also appears to indicate that its calculation will be adjusted to conform with any clarification of the scope of the relevant OCTG orders that the DOC may issue. Tenaris considers imports of mechanical and other pipe to be out of scope of the OCTG orders and, on January 30, 2026, filed a scope clarification request with the DOC , which accepted the request and initiated a scope inquiry. On July 16, 2026, the DOC issued a preliminary scope ruling indicating that none of the three categories of mechanical and other pipe imported by Tenaris are covered by the scope of the antidumping duty orders on OCTG from Argentina and Mexico . This preliminary determination supports Tenaris's position that its imports of mechanical and other pipe are out of scope of the OCTG orders and, if sustained in the DOC's final scope rul ing, would be expected to negate the basis for CBP's calculated loss of revenue with respect to such imports during 2022, 2023 and 2024. The preliminary ruling may be challenged by domestic petitioners; DOC's deadline to issue a final scope ruling is December 2026. Based on the advice of counsel, and taking into account that this preliminary ruling is subject to further comment and final determination, Tenaris continues to believe that the loss contingency arising from the CBP report is neither probable nor capable of a reliable estimate at this time and, accordingly, no provision has been made with respect to such 2022, 2023 and 2024 imports.

CBP separately instructed Tenaris to modify its treatment of imports effective January 2025 and forward so that imports of certain mechanical and other pipe would be considered to be subject to the antidumping orders on OCTG from Argentina and Mexico. As a result, unless CBP changes its stated position on its own initiative or after clarification by DOC, the entries on and after January 1, 2025, will require the payment of antidumping duty deposits, and the liquidation of these entries will remain suspended during the antidumping administrative review process. The DOC's preliminary scope ruling of July 16, 2026, favors Tenaris's position that such mechanical and other pipe is out of scope, and, if confirmed in the DOC's final scope decision, would be expected to support the elimination of this deposit requirement on future entries of mechanical and other pipe products at issue , and trigger the refund by CBP of deposits paid subject to CBP's instruction as from January 2025. However, pending a final and non- appealable scope determination, CBP has not modified its position, and Tenaris continues to pay such deposits, t he amount of which is reflected in Tenaris’s costs.

 ENARSA claim relating to alleged price differences of PUI gas On May 21, 2026, Siderca S.A.I.C. ("Siderca"), an Argentine subsidiary of the Company , was served with a lawsuit filed by Energía Argentina S.A. ("ENARSA") claiming alleged price differences with respect to gas supplied during the months of June, July and August 2013. ENARSA contends that the applicable price is USD7.50/MMBTU, while Siderca maintains that the correct price is USD2.68/MMBTU (the price at which Siderca paid the disputed invoices in June 2015), giv ing rise to a claimed balance in ENARSA's favor of approximately USD25.4 million as principal. The lawsuit also involves a dispute regarding the currency in which the potential credit should be denominated and the applicable exchange rate. On June 23, 2026, Siderca filed its answer to the complaint, raising a statute of limitations defense, res judicata based on a 2018 ENARGAS resolution that had set the applicable price at USD2.68/MMBTU, and defenses on the merits as to both the price and the exchange rate applied by ENARSA. If the pending proceedings were resolved entirely against Siderca, Siderca could be required to pay an aggregat e amount, estimated as of June 30, 2026, of approximately $48.0 million, plus legal fees . The Company believes that , even in the event of an unfavorable outcome on this matter, the resulting loss would not be material .

(ii) Commitments and guarantees Set forth is a description of Tenaris’s main outstanding commitments:

 Certain subsidiaries of the Company are parties into a long- term contract with Praxair S.A. for the service of oxygen and nitrogen supply. As of June 30, 2026 , the aggregate amount to take or pay the committed volumes for an original 14- year term totaled approximately $ 23.4 million.

 A Mexican subsidiary of the Company is a party to 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 bas is 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 Mexican 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 proce eds of such sale.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

24  Certain subsidiaries of the Company are parties to a long- term contract with the supplier JFE Steel Corporation for the purchase of tubular material, including 13 chrome alloy products. Such contract foresees a penalty for a maximum amount of $16.2 million in case of early termination. The contract will be in effect until June 30, 2029.

 Certain subsidiaries of the Company are parties to contracts with Vestas Argentina for the maintenance of wind farms in Argentina. Such contract s foresee penalt ies for a maximum amount of $22.4 million in case of early termination.

 A U.S. subsidiary of the Company is a party to a framework supply agreement with Nucor Steel Memphis Inc.

(“Nucor”) pursuant to which Nucor agrees to supply, and the subsidiary intends to purchase, up to a specified tonnage of steel bars per month, subject to a rolling three -month forecast provided by the subsidiary. The subsidiary has no obligation to purchase volumes outside the forecasted quantities. Prices are determined in accordance with a contractual pricing formula, subject to applicable surcharges and adjustments. The contract became effective in January 2026, with an original duration of 1 year.

 An Argentine subsidiary of the Company is party to two agreements for the acquisition of natural gas transportation services for its facilities. As of June 30, 2026, the aggregate commitments under these agreements amounted to approximately $1 78.9 million. The agreements expire in April 2027 and April 2062, with outstanding commitments of approximately $142.3 million and $36 .6 million, respectively.

 A subsidiary of the Company has entered into an energy release mechanism, under which it has a contractual obligation to develop new renewable energy capacity, either directly or by transferring such obligation to third parties, within a defined timeframe. In the event of non- fulfilment, the Company is required to financially reimburse the benefit received in accordance with the contractual terms.

In addition, Tenaris (i) covered certain obligations of Techgen as described in note 17 (c) and (ii) issued performance guarantees mainly related to long- term commercial contracts with several customers for approximately $3.6 billion as of June 30, 202 6.

(iii) Restrictions on 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 June 30, 2026 , 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.

On May 6, 2025, the extraordinary general meeting of shareholders approved the cancellation of 90,762,598 ordinary shares held in treasury by the Company repurchased during the second, third and fourth tranches of the first share buyback program and throughout the second share buyback program and the corresponding reduction of the issued share capital of the Company and, accordingly, the legal reserve was proportionally reduced.

On May 12, 2026 , the extraordinary general meeting of shareholders approved the cancellation of 62,355,174 ordinary shares held in treasury by the Company repurchased during the third share buyback program and the corresponding reduction of the issued share capital of the Company and, accordingly, the legal reserve was proportionally reduced.

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.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

25 19 Tariffs on steel and other imports

Effective March 12, 2025, the U.S. government introduced changes to the tariffs applicable to imported steel products, including those produced and sold by the Company. These changes include the extension of a 25% tariff to all imported steel products through a phased -in implementation plan, initially applying to raw steel products, with downstream (“derivative”) products being subject to the tariff starting June 1, 2025. Exclusions that previously exempted specific products and countries from the existing tariffs were discontinued.

On June 4, 2025, the U.S. government increased these tariffs to 50% (with the exception of steel imports from the United Kingdom, whose tariffs remain at 25%), and on June 16, 2025, the list of steel derivative products to which the tariffs apply was expan ded. The list of steel derivative products was further expanded on August 18, 2025.

On August 2, 2025, the Canadian government applied Section 53 tariff rate quotas on imports of steel products, with tariffs of 50% (additional to normal duty rates) applying to imports of steel products in excess of established quotas. The tariff rate quot as were initially set at 100% of 2024 imports for the group of countries having a free trade agreement with Canada and 50% of 2024 imports for the group of countries without a free trade agreement with Canada. As members of the USMCA trade agreement, these tariffs do not apply to imports from Mexico and the United States, although separately Canada is applying a 25% tariff on imports of steel products from the United States as a retaliatory measure for the U.S. tariffs on steel products. On December 26, 2025, the Canadian government reduced the tariff rate quotas to 75% of 2024 imports for the group of countries having a free trade agreement with Canada and 20% of 2024 imports for the group of countries without a free trade agreement with Canada. In December 2025, the Canadian government provided an exemption from the tariff for steel bars imported by Tenaris for its seamless pipe operations in Sault Ste. Marie with retroactive effect.

On July 1, 2026, the EU introduced its New Trade Tool for imports of steel products, replacing its previous safeguard. The new measure reduced the volume allowed to enter without duties by 47% (18.3MM to ns per year) and increased the tariff payable on imports above the quota to 50% from the previous 25%. The quota allocation is split between countries with EU free trade agreements (FTA) and all other countries, with separate quota components for each group. The annual quota for seamless pipes is 269 thousand tons with country -specific quotas for China, Ukraine, Brazil, Argentina and Singapore.

U.S., Canadian and EU tariffs on steel imports and other tariffs (including those arising under a reciprocal tariff regime implemented by the U.S. government effective August 1, 2025, or under the retaliatory measures enacted by other countries), are affecting market prices and dynami cs, supply chains, and cost structures. Changes in some of these tariff rates continue to be made, or threatened, in response to further negotiations with trading partners and/or measures taken, retaliatory or otherwise, by som e countries that are deemed hostile acts or against the interests of other countries by the governments of such countries. As a result, a great degree of uncertainty remains in the market.

20 Foreign exchange control measures in Argentina Between September 2019 and December 2023, the Argentine government imposed significant restrictions on foreign exchange transactions. After a new administration took office in Argentina in December 2023, some of these restrictions have been progressively lifted or eased. 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 (“MULC”) and converted into Argentine pesos within specified deadlines, which vary depending on whether transactions involve related parties and on the timing of collection. Payments for imports of goods are allowed upon customs clearance, while payments for services are permitted either upon accrual (non- related parties) or after a 90 -day deferral (related parties). Payments for capital goods imp orts follow a phased schedule.

 Access to the MULC to pay dividends is permitted for distributable earnings corresponding to full fiscal years commencing after January 1, 2025. Access to the MULC to pay dividends for accumulated earnings relating to prior years remains subject to the approval of the Argentine Central Bank.

Access to foreign currency and transfers out of Argentina to make payments that remain restricted can be achieved through securities transactions involving securities listed both in Argentina and in other markets, resulting in a different implicit exchange rate, generally higher than the official exchange rate. Pursuing any such transactions by Argentine companies and, in certain cases, its shareholders and affiliates, result in temporary restrictions for the Argentine compan ies to access the MULC.

It is still unclear if or when the Argentine authorities will eliminate or loosen the remaining restrictions.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

26 As of June 30, 2026, Tenaris had a net short Argentine peso exposure of approximately $14.2 million. A further devaluation could result in losses related to deferred tax charges due to the deterioration of the tax value of fixed assets.

Argentine subsidiaries represented approximately 13% of total equity and 17% of total sales, with peso -denominated assets and liabilities valued at the official exchange rate.

Despite recent easing measures, this context of volatility and uncertainty remains in place as of the issue date of these Consolidated Condensed Interim Financial Statements. 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. These Consolidated Condensed Interim Financial Statements should be read taking into account these circumstances.

21 Cash flow disclosures Six-month period ended June 30,

2026 2025

(Unaudited)

(i) Changes in working capital Inventories (124,482) 266,685 Receivables and prepayments, contract assets and current tax assets 5,146 (83,632) Trade receivables (16,539) 52,994 Other liabilities and current tax liabilities 92,839 83,782 Customer advances (38,586) (70,595) Trade payables (2,098) 1,082

(83,720) 250,316

(ii) Income tax accruals less payments Tax accrued 185,419 186,684 Taxes paid (283,859) (277,477)

(98,440) (90,793)

(iii) Interest accruals less payments/collections, net Interest accrued, net (94,169) (120,656) Interest received 123,826 121,668 Interest paid (12,574) (14,051)

17,083 (13,039)

22 Related party transactions

As of June 30, 2026:

 San Faustin, a Luxembourg société anonyme , owned 690,005,187 shares in the Company, representing 68.34% of the Company’s issued shares 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 shares.

 Rocca & Partners Stichting Administratiekantoor Aandelen San Faustin (“RP STAK”), a private foundation (Stichting) located in the Netherlands, controls San Faustin through the holding of voting shares sufficient in number to influence matters affecting or submitted to a vote of the shareholders of San Faustin S.A., including the election of directors and the approval of certain corporate transactions and other matters concerning San Faustin S.A.'s policies.

 No person or group of persons controls RP STAK.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

27 On September 19, 2025, the Company announced that San Faustin and Techint had filed with the SEC an amendment to their Schedule 13D, reporting that, for portfolio- management purposes and in response to the Company’s ongoing share repurchase program discussed below, which caused San Faustin’s beneficial ownership interest in the Company to passively increase, on September 17, 2025, the board of directors of San Faustin had authorized Techint to sell a number of its ordinary shares of the Company, provided that Techint’s ownership stake in the Company should not fall below 67% of the Company’s total outstanding ordinary shares. The reporting persons stated that the precise timing, amount and manner of any such sales will depend upon market conditions and other factors, and that there is no assurance that any sales will be completed or the timing thereof. The reporting persons also noted that, although they do not currently intend to purchase ordinary shares or to reduce their beneficial ownership below 67% of the Company’s total outstanding ordinary shares, they may from time to time, depending on market conditions and other factors, purchase or sell additional ordinary shares, and that, except as described above, they do not have any present plans or proposals that relate to or would result in any extraordinary corporate transaction or lead to the acquisition of additional securities .

On December 17, 2025, the Company announced that San Faustin and Techint had filed with the SEC a new amendment to their Schedule 13D, reporting that, further to the previously -reported authorization, (i) between December 9, 2025 and December 12, 2025, Techint sold a total of 2,600,000 Tenaris ordinary shares pursuant to a non- discretionary sales mandate established with a European broker -dealer regulated in the European Union that ended on December 12, 2025;

and (ii) on December 12, 2025, Techint entered into a non- discretionary accelerated share disposal agreement with an European financial institution regulated in the European Union for the sale of up to 21,000,000 ordinary shares of Tenaris during the period starting on December 15, 2025 and ending no later than May 19, 2026 (the “ASD Program”). San Fausti n and Techint stated, among other things, that under the ASD Program the bank will make all trading decisions concerning the timing of the sales of Tenaris ordinary shares and all sales under the ASD Program will be conducted in European regulated stock markets, and that the ASD Program will be executed in compliance with applicable rules and regulations. San Faustin and Techint noted that, following completion of the ASD Program, they may from time to time, depending on market conditions and other factors, sell additional ordinary shares of the Company in accordance with the above -mentioned sales authorization.

Between December 9, 2025, and June 30, 2026 , Techint sold 23,600, 000 ordinary shares of Tenaris .

Based on the information most recently available to the Company, Tenaris’s directors and senior management as a group owned 0.09% of the Company’s share capital and voting rights.

Transactions and balances disclosed as with “associated companies” are those with companies over which Tenaris exerts significant influence in accordance with IFRS but does not have control. Transactions and balances disclosed as with “joint ventures” are those with companies over which Tenaris exerts joint control in accordance with IFRS but does not have control. All other transactions and balances with related parties that are not non- consolidated companies are disclosed as “other related parties” .

The following transactions were carried out with related parties:

Six-month period ended June 30,

2026 2025

(i) Transactions (Unaudited) (a) Sales of goods, services and other transactions Sales of goods to associated companies 7,439 9,597 Sales of goods to other related parties 46,794 40,771 Sales of services and others to associated companies 2,581 2,170 Sales of services and others to joint ventures 74 70 Sales of services and others to other related parties 63,970 84,023

120,858 136,631

(b) Purchases of goods, services and other transactions Purchases of goods to associated companies 45,481 97,151 Purchases of goods to joint ventures 34,984 30,408 Purchases of goods to other related parties 17,076 12,965 Purchases of services and others to associated companies 9,608 8,161 Purchases of services and others to other related parties 25,128 27,563

132,277 176,248

(c) Financial Results Income from joint ventures 1,054 2,964

1,054 2,964

(d) Dividends

Dividends received from associated companies 29,863 41,348 Dividends distributed to Techint Holdings S.àr.l. 414,003 399,619

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

28

At June 30, At December 31,

2026 2025

(ii) Period -end balances (Unaudited) (a) Arising from sales / purchases of goods / services and other

transactions

Receivables from associated companies 3,985 4,641 Receivables from joint ventures 14 69,447 Receivables from other related parties 25,500 45,476 Payables to associated companies (20,075) (22,214) Payables to joint ventures (6,275) (6,892) Payables to other related parties (9,219) (8,196)

(6,070) 82,262

(b) Financial debt Lease liabilities from associated companies (657) (857) Lease liabilities from other related parties (3,050) (1,589)

(3,707) (2,446)

In addition to the tables above, the Company issued certain guarantees in favor of Techgen; for further details, please see note 17 (c) and note 18 (ii). No other material guarantees were issued in favor of other related parties.

23 Share buyback program s

First share buyback program On November 1, 2023, the Company’s board of directors approved a share buyback program of up to $1.2 billion, to be executed within a year, with the intention to cancel the ordinary shares acquired through the program. The share buyback program was carried out under the authority granted by the annual general meeting of shareholders held on June 2, 2020, up to a maximum of 10% of the Company’s shares.

For purposes of carrying out each tranche of the first share buyback program, the Company entered into non-discretionary buyback agreements with primary financial institutions that made trading decisions concerning the timing of the purchases of the Company’s ordinary shares independently of and uninfluenced by Tenaris and acted in compliance with applicable rules and regulations, including the Market Abuse Regulation 596/2014 and the Commission Delegated Regulation (EU) 2016/1052.

During the first share buyback program, which was divided into four tranches and ran from November 5, 2023, to (and including) August 2, 2024, the Company repurchased 71,679,768 ordinary shares, representing 6.07% of the Company’s issued share capital as m easured at the beginning of the first program, for a total consideration of approximately $1.2 billion (excluding incidental transaction fees).

The shares acquired during the first tranche of the first share buyback program were cancelled at the extraordinary shareholders meeting held on April 30, 2024, and the remaining shares acquired during the second, third and fourth tranches of the first sha re buyback program were cancelled at the extraordinary shareholders meeting held on May 6, 2025, as further described below.

Second share buyback program On November 6, 2024, the Company’s board of directors approved a follow -on share buyback program of up to $700 million (excluding incidental transaction fees), subject to a maximum of 46,373,915 ordinary shares, representing the remaining 3.93% of the Company’s issued share capital (measured as of the launch of the first share buyback program), to complete the maximum of 10% of the share capital that could be repurchased by the Company at the time, with the intention to cancel the ordinary shares acquired through the program. The second share buyback program was carried out under the authority granted by the annual general meeting of shareholders held on June 2, 2020, to repurchase up to a maximum of 10% of the Company’s shares.

For purposes of carrying out the second share buyback program, the Company entered into a non- discretionary buyback agreement with a primary financial institution, which made trading decisions concerning the timing of the purchases of the Company’s shares independently of and uninfluenced by Tenaris and acted in compliance with applicable rules and regulations, including the Market Abuse Regulation 596/2014 and the Commission Delegated Regulation (EU) 2016/1052.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

29

During the second share buyback program, which ran from November 11, 2024, to (and including) March 4, 2025, the Company repurchased 36,862,132 ordinary shares, representing 3.12% of the Company’s issued shares as measured at the beginning of the first sha re buyback program, for a total consideration of approximately $700 million (excluding incidental transaction fees).

On May 6, 2025, the extraordinary shareholders meeting approved the cancellation of 90,762,598 ordinary shares held in treasury by the Company, which had been acquired during the second, third and fourth tranches of the first share buyback program and second share buyback program, and resolved to approve the corresponding reduction of the issued share capital of the Company and the amendment of the first paragraph of article 5 of the Company’s articles of association. As a result, effective May 6, 2025, the issued share capital of the Company was reduced from $1,162,757,528 (represented by 1,162,757,528 shares with a par value of $1 per share) to $1,071,994,930 (represented by 1,071,994,930 shares with a par value of $1 per share).

Third share buyback program On May 27, 2025, the Company’s board of directors approved a third share buyback program of up to $1.2 billion (excluding incidental transaction fees), to be executed within a year, with the intention to cancel the ordinary shares acquired through the program. The third share buyback program is carried out under the authority granted by the annual general meeting of shareholders held on May 6, 2025, which renewed the authorization to purchase, acquire or receive, from time to time, Company shares, including shares represented by ADRs, on such terms and conditions as may be approved by the board of directors up to a maximum of 10% of the Company’s shares.

For purposes of carrying out each tranche of the third share buyback program, the Company entered into a nondiscretionary buyback agreement with a primary financial institution, which makes trading decisions concerning the timing of the purchases of the Company’s shares independently of and uninfluenced by Tenaris and acts in compliance with applicable rules and regulations, including the Market Abuse Regulation 596/2014 and the Commission Delegated Regulation (EU) 2016/1052.

The third share buyback program was divided into two tranches. The first tranche of the program, which covered up to $600 million (excluding incidental transaction fees) , ran from June 9, 2025, to (and including) September 30, 2025. Under the first tranche of the program, the Company repurchased 33,059,955 ordinary shares, representing 3.08% of the Company’s issued shares as measured at the beginning of the first tranche of the program, for a total consideration of approximately $584 million (excluding inci dental transaction fees) .

The second tranche of the third share buyback program, which covered up to $600 million (excluding incidental transaction fees) , ran from November 3, 2025 , and was originally scheduled to end no later than April 30, 2026. Under the second tranche of the program, the Company repurchased 29,295,219 ordinary shares, representing 2.73% of the Company's issued shares as measured at the beginning of the second tranche of the program, for an aggregate consideration of approximately $583. 6 million (excluding incidental transaction fees ), thereby substantially completing its targeted repurchases .

On February 23, 2026, the Company announced its decision to terminate, effective March 3, 2026, the second tranche of the third share buyback program. In a context of high volatility in the market, allowing the second tranche of the program to continue as initially scheduled would, by application of the customary mechanics in the existing buyback agreement, have resulted in a significant incremental pay -out to its counterparty. Accordingly, following the expiration of the blackout period corresponding to the Company’s annual earnings release on February 20, 2026, the Company exercised its right to terminate its existing buyback agreement on the first date it was allowed to do so under the terms of the agreement , and in March 2026, paid the incidental transaction fees .

During the six -month period ended June 30, 2026, the Company purchased 2,184,202 shares, for approximately $89.6 million (including a negative performance amount of $ 47.1 million ). During the six -month period ended June 30, 2025 , the Company purchased 12,277,261 shares, for approximately $235 million (including a positive performance amount of $1.1 million) under the second share buyback program and purchased 13,094,268 shares, for approximately $237 million under the third share buyback program.

On May 12, 202 6, the extraordinary shareholders meeting approved the cancellation of 62, 355,174 ordinary shares held in treasury by the Company, which had been acquired during the third share buyback program, and resolved to approve the corresponding reduction of the issued share capital of the Company and the amendment of the first paragraph of article 5 of the Company’s articles of association. As a result, effective May 12, 2026 , the issued share capital of the Company was reduced from $1,071,994,930 (represented by 1,071,994,930 shares with a par value of $1 per share) to

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

30 $1,009,639,756 (represented by 1,009,639,756 shares with a par value of $1 per share). There were no ordinary shares held in treasury by the Company as of June 30, 2026.

Further information on the share buyback programs and share repurchases thereunder is available on Tenaris’s corporate website under the " Share Buyback Program Section ".

24 Business combinations

Acquisition of a scrap processing business in Beaver Falls On November 12, 2025, Tenaris completed the acquisition of a scrap processing business in Beaver Falls, Pennsylvania, for a purchase price of $17.5 million paid in cash. The fair value estimation of the assets acquired was finalized during the three -months period ended March 31, 2026, and amounted to approximately $15.7 million , which was allocated mainly to Property, Plant and Equipment. The purchase price allocation resulted in a goodwill of approximately $1.8 million . Tenaris consolidated the balances and results of operations of the acquired business as from November 12, 2025.

The acquired business’s contribution to Tenaris’s revenues and results was non- material, and it was assigned to the Tubes segment. Acquisition -related costs for the year ended December 31, 2025, amounted to $0.2 million and were included in general and administrative expenses.

Acquisition of the oilfield division of AllTorque

In March 2026, Tenaris completed the acquisition of the oilfield division of AllTorque , a leading original equipment manufacturer of tubular running technology based in Red Deer, Alberta , Canada , for a purchase price of $4.7 million paid in cash. The preliminary fair value of the assets acquired , which amounted to approximately $1.5 million, was allocated to Property, Plant and Equipment. The preliminary purchase price allocation resulted in a goodwill of approximatel y $3.2 million. Tenaris consolidated the balances and results of operations of the acquired business as from March 25, 2026 . Had the transaction been consummated on January 1, 2026 , Tenaris’s unaudited pro forma net sales and net income would not have changed materially. Acquisition- related costs were not material and were included in general and administrative expenses.

25 Agreement for acquisition of Artrom Steel Tubes S.A.

On May 8, 2026, Tenaris entered into a definitive agreement to acquire from GLGH Steel, LLC, a U.S. -based company, 100% of the share capital of Artrom Steel Tubes S.A. ("Artrom"), for an aggregate purchase price of EUR86 million, on a cash -free and debt -free basis, including a normalized level of working capital. Artrom is a Romanian manufacturer of steel and seamless steel pipes, with annual steelmaking capacity of approximately 450,000 metric tons at its facility in Reșița and seamless pipe rolling capaci ty of up to 200,000 metric tons at its Slatina facility. The transaction is subject to customary regulatory conditions, including clearance from the European Union competition authorities and Romanian government approvals, and closing is expected to occur during the fourth quarter of 2026.

Consolidated Condensed Interim Financial Statements For the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

31 26 Middle East war

In March 2026, the armed conflict involving the United States and Israel against Iran, and retaliatory actions by Iran across the broader Middle East, led to a closure of the Hormuz Strait, through which almost 20% of the world’s oil and LNG is shipped, resulting in extreme volatility of e nergy prices and a disruption to oil and LNG production and transportation in the region. There is uncertainty about the full impact and consequences resulting from the conflict.

In early April 2026, a ceasefire between the United States and Iran came into effect, during which Iran allowed commercial shipping through the Strait of Hormuz, although traffic remained far below pre -war levels. On April 12, 2026, negotiations between the United States and Iran broke down and the U.S. government introduced a naval blockade of Iranian ports. For the following two months, the United States, Iran and Israel intermittently engaged in strikes and counterstrikes on selected targets while the st rait of Hormuz remained largely closed to commercial shipping.

On June 14, 2026, the United States and Iran announced a preliminary agreement , or truce, to end the conflict and reopen the Strait of Hormuz, and the U.S. government lifted its naval blockade of Iranian ports, with a memorandum of understanding formally signed on June 17, 2026, and the blockade's removal confirmed by U.S. Central Command on June 18, 2026. Commercial shipping through the Strait resumed gradually over the following weeks, although traffic volumes, insurance costs and shipping risk remained e levated relative to pre- war levels. In early July 2026, the truce broke down as the U.S. government resumed airstrikes against Iranian military and oil -related targets, and Iran launched retaliatory strikes against U.S. forces in the region and against Bahrain, Kuwait, Qatar and Jordan. As of the date of these Consolidated Condensed I nterim Financial Statements, hostilities are ongoing, and it is uncertain whether the truce or negotiations towards a final resolution will resume , or the ultimate scope, durat ion and impact of the conflict on regional operations , the global economy and global oil and LNG supplies.

Tenaris maintains significant industrial operations and customer relationships in the Middle East. A prolonged conflict or an escalation of hostilities in the region could disrupt Tenaris's operations at these facilities, impair its ability to fulf ill customer orders, increase the costs of transportation (including as a result of the need to arrange for alternative transportation both through alternative ports or by land and/or additional insurance costs), result in potential order cancellations, restrict e mployee mobility, damage physical infrastructure, and hinder supply of raw materials, semi -

finished steel and other inputs to its regional mills.

The Iran conflict adds to existing supply chain challenges, including trade restrictions from tariffs and supply chain disruptions that have continued since the Russia -Ukraine war. A sustained disruption to the Strait of Hormuz could significantly increase oil prices and fuel broader inflation, slow global economic activity and reduce demand for Tenaris's products. The imposition of additional sanctions targeting Iran- linked maritime networks and the potential for expanded trade restrictions may further con strain sourcing alternatives and increase compliance costs. Tenaris is unable at this time to predict the evolution or ultimate outcome of these developments, or to quantify the impact they may have on its business or financial condition.

27 Events after the reporting period

Interim dividend payment On August 5, 2026 , the Company’s Board of Directors approved the payment of an interim dividend of $0. 59 per outstanding share ($ 1.18 per ADS), or approximately $600 million, payable on November 25, 2026 , with record date on November 24, 2026 .

Carlos Gómez Álzaga Chief Financial Officer