Tenaris S A : 2025 Annual Report (66c89b)

Annual Report

2025

TENARIS S.A.

26, Boulevard Royal - 4th Floor L-2449 - Luxembourg

R.C.S. Luxembourg: B 85203

TABLE OF CONTENTS

LETTER FROM THE CHAIRMAN 5

CERTAIN DEFINED TERMS 7

PRESENTATION OF CERTAIN FINANCIAL AND OTHER INFORMATION 9

CAUTIONARY STATEMENT CONCERNING FORWARD-LOOKING STATEMENTS 10

RISK FACTORS 11

Risks Relating to our Business and Industry 11

Risks Relating to our Structure 19

Risks Relating to shares and ADSs 20

INFORMATION ON THE COMPANY 22

Overview 22

History and Development of the Company 23

Business Overview 25

Our Competitive Strengths 27

Business Segments 28

Our Products 29

Production Process and Facilities 30

Sales and Marketing 38

Competition 46

Capital Expenditure Program 49

Raw Materials and Energy 51

Product Quality Standards 55

Research and Development 56

Insurance 57

Organizational Structure and Subsidiaries 58

Operating and Financial Review and Prospects 61

Overview 61

Operating Results 63

Liquidity and Capital Resources 69

Trend Information 73

Critical Accounting Estimates 77

Corporate Governance Statement 78

Corporate Governance 78

Summary of differences with NYSE standards 85

Directors, Senior Management and Employees 88

Directors and Senior Management 88

Compensation 96

Board Practices 97

Employees 100

Share Ownership 101

Recovery of Erroneously Awarded Compensation 102

Major Shareholders and Related Party Transactions 103

Major Shareholders 103

Related Party Transactions 104

SUSTAINABILITY STATEMENT 107

Sustainability in Tenaris 107

Basis for Presentation 108

Policies and Procedures 109

The Administrative and Management Bodies 111

Due Diligence 112

Strategy and Business Model 113

Double Materiality Assessment 114

Identifying and Assessing Material Impacts, Risks and Opportunities 114

Material Impacts, Risks and Opportunities ("IROs") 117

Environment 119

Environmental Management System 120

Climate Change 121

Air Quality 130

Water Management 132

Circularity 135

Biodiversity 138

EU Taxonomy (Article 8 of Regulation (EU) 2020/852) 139

Social 147

Human Capital 147

Health and Safety 154

Community Relations 159

Our Value Chain 165

Governance - Business Conduct 174

Compliance Culture 176

Business Conduct Compliance Program 177

Business Conduct Risk Management 179

Monitoring, Investigations, Audit Reviews and Compliance Assurance 179

Compliance Line 181

Human Rights 183

Annexes 186

Annex I: Sustainability Statement Accounting Policies 186

Annex II: Sustainability performance indicators 192

Annex III: ESRS Content index 199

Annex IV: SASB Iron & Steel Producers Content Index 203

Annex V: Independent Limited Assurance Report 203

LEGAL AND FINANCIAL INFORMATION 218

Financial Information 218

Consolidated Statements and Other Financial Information 218

The Offer and Listing 220

Offer and Listing Details 220

Additional Information 221

Exchange Controls 221

Taxation 222

Documents on Display 229

Quantitative and Qualitative Disclosure about Market Risk 230

Description of Securities Other Than Equity Securities 233

American Depositary Shares 233

Controls and Procedures 235

Principal Accountant Fees and Services 236

Purchases of Equity Securities by the Company and Affiliated Purchasers 238

Insider Trading Policy 242

Cybersecurity 243

FINANCIAL STATEMENTS 245

Consolidated Financial Statements 245

Annual Accounts (Luxembourg GAAP) 331

MANAGEMENT CERTIFICATION 351

EXHIBITS 352

‌LETTER FROM THE CHAIRMAN

As I write this letter, the world of energy is witnessing a conflagration at its heart in the Middle East. The Strait of Hormuz, through which 20% of the world's oil and 20% of its LNG should pass, is effectively closed, and many of the producing fields in the region are being shut in while some are being damaged by the hostilities. The longer the conflict continues, the greater will be its impact on the energy industry and the global economy. As we confront this new reality, our immediate priorities are the safety of our employees and supporting our customers.

2025 was a year in which Tenaris demonstrated the resilience of its operations in the face of a disruptive geopolitical environment and lower activity in key markets. Thanks to our global industrial system and flexible supply chain, the depth of the service we offer our customers and the commitment of our employees, we were able to respond rapidly to the tariffs and other challenges we faced during the year. These same elements will help us to navigate the challenges ahead.

Our results remained remarkably stable through the year, which we completed with an EBITDA of $2.9 billion and net income of $2.0 billion on net sales of $12.0 billion. Free cash flow amounted to $2.0 billion, all of which was distributed to shareholders through dividends and share buy backs. We are proposing a further increase of the annual dividend per share of 7% over that for the previous year. At the same time, we maintained a net cash position of $3.3 billion.

In the USA and Canada, the year was marked by further oil and gas industry consolidation and productivity improvements, a lower rig count, and the extension of Section 232 tariffs to the imports of all steel products, including the steel bars we require for our seamless pipe operations at Bay City, and their subsequent increase to 50%.

In this environment, Tenaris raised the performance of its US production and supply chain system, with its Koppel steel shop, main pipe production plants at Bay City, Hickman and Ambridge and various pipe processing facilities acting in concert to achieve record levels of production and supply 90% of our US sales. In both the US and Canada, we strengthened our market position and extended the differentiation we offer under our Rig Direct® service model. As customers targeted operational efficiencies, we continued to develop and roll out our RunReady™ and well integrity services that support them by increasing safety and reliability at the well site.

Major oil and gas companies are seeking new production reserves to meet a more resilient long-term demand outlook, and are looking beyond the shales to deepwater developments and exploration in frontier regions.

Tenaris, with its capacity to develop products for complex operations and to support fast-track development with services and the integrated supply of advanced coated line pipe solutions at scale, is working with most of these companies as they develop such projects.

As new offshore projects are sanctioned around the world, we see many opportunities to renew our order backlog, while we execute on existing commitments. Currently, we are delivering casing for Shell's Sparta 20K project in the US deepwater, extending our services for ExxonMobil's operations in Guyana and preparing a service base for TotalEnergies GranMorgu development in Surinam, while planning the production of seamless and welded line pipe and coating for the third phase of TPAO's Sakarya gas development in the Black Sea.

In Latin America, the Mexican government is taking steps to address the financial difficulties of Pemex, which took a toll on oil and gas drilling activity in the country last year, while, in Argentina, domestic companies have been able to raise $4 billion in financing to develop infrastructure and expand production and operations at the Vaca Muerta shale. We supplied the Vaca Muerta Sur pipeline and are currently supplying the Duplicar Norte pipeline. We are also investing to expand our new fracking and coiled tubing service business and expect to put a third set of equipment to work before the end of the year.

In Venezuela, following the intervention of the US government, we are resuming our service to Chevron's operations and building up our service capabilities in the country to support future increases in drilling activity.

In the Middle East, where many oil and gas operations are currently being affected, we consolidated our presence with the award of a long-term agreement for the supply of OCTG to the Northwest Field

development in Qatar, while, in the Emirates, we enhanced our Rig Direct® service to ADNOC, delivering a record amount of OCTG. In Saudi Arabia, although conventional drilling activity was reduced during the year, we completed an expansion at our local large diameter facility from which we are supplying line pipe for the development of gas infrastructure, in addition to the OCTG we supply for Aramco's drilling operations.

Our globally integrated industrial and supply chain operations have been key to our ability to respond effectively to the different events we faced during the year. We continue to invest in enhancing the efficiency and digital integration of these operations as well as reducing their environmental impact. This includes the integration of advanced AI capabilities into our industrial and administrative processes.

We made further progress towards our mid-term target of reducing the carbon emissions intensity of our operations as we brought our second wind farm in Argentina into operation. The two wind farms now supply essentially all of the energy requirements for our electric steel shop and operations in Campana.

As an industrial company, our commitment to the safety of our employees and the sustainability of our communities is absolute. Although our safety indicators have improved this year, we continue to reinforce our preventive actions and monitor our performance in these aspects.

The reach of our community education programs, which are focused on strengthening technical education and employment prospects, now extends to 18,000 students and teachers. Our Roberto Rocca Technical School in Campana, for example, opens its doors, to offer technical programs and the opportunity to receive internationally recognized technical qualifications, to almost four times as many students as its quota of full-time students. We have now decided to build a further Roberto Rocca Technical School in Veracruz to extend a network that also includes schools sponsored by our sister company Ternium in Monterrey, Mexico and Santa Cruz (RJ), Brazil.

Tenaris, with its presence across the world, competitive differentiation in product and service, the quality and compliance of its decentralized operations and the financial strength to support its strategy, remains well placed to confront an unpredictable and volatile future.

I would like to thank all our employees and the communities which sustain our operations for their constant commitment and engagement, that have made possible our results and achievements this year. I would also like to thank our customers and suppliers for their ongoing trust and support.

Sincerely,

Paolo Rocca March 30, 2026

‌CERTAIN DEFINED TERMS

Unless otherwise specified or if the context so requires:

• References in this annual report to "Tenaris", "we", "us" or "our" are to Tenaris S.A. and its consolidated subsidiaries. See "II. Accounting Policies A. Basis of presentation" and "II. Accounting Policies B. Group accounting" to our audited consolidated financial statements included in this annual report.

• References in this annual report to "the Company" are exclusively to Tenaris S.A., a Luxembourg

  société anonyme.

• References in this annual report to "San Faustin" are to San Faustin S.A., a Luxembourg société anonyme and the Company's controlling shareholder.

• "ADSs" refers to the American Depositary Shares, which are evidenced by American Depositary Receipts, and represent two shares each.

• "API" refers to the American Petroleum Institute.

• "BAT" refers to the best available technologies.

• "billion" refers to one thousand million, or 1,000,000,000.

• "BRL" refers to the Brazilian real.

• "CBAM" refers to the EU Carbon Border Adjustment Mechanism.

• "CCS" refers to carbon capture and storage.

• "DMA" refers to the Double Materiality Assessment.

• "EAF" refers to electric arc furnaces.

• "EC" refers to the European Commission.

• "EMS" refers to the Environmental Management System.

• "ESG" refers to Environmental, Social and Governance.

• "ESRS" refers to the European Sustainability Reporting Standards.

• "ETS" refers to the European Emissions Trading System.

• "EU" refers to the European Union.

• "EUR" refers to the Euro.

• "FCPA" refers to the U.S. Foreign Corrupt Practices Act.

• "GHG" refers to greenhouse gas.

• "IAS" refers to International Accounting Standard.

• "IFRS" refers to International Financial Reporting Standards Accounting Standards as issued by the International Accounting Standards Board.

• "IPCC" refers to the Intergovernmental Panel on Climate Change.

• "ISO" refers to the International Organization for Standardization.

• "ksi" refers to kilopound per square inch.

• "LNG" refers to liquefied natural gas.

• "NYSE" refers to the New York Stock Exchange.

• "OCTG" refers to oil country tubular goods. See "Information on the Company - Business Overview -Our Products".

• "OECD" refers to the Organization for Economic Co-operation and Development.

• "OPEC" refers to the Organization of Petroleum Exporting Countries.

• "QHSE" refers to Quality, Health, Safety, and Environment.

• "QMS" refers to the Quality Management System.

• "R&D" refers to research and development.

• "RCP" refers to the Representative Concentration Pathway.

• "SAR" refers to the Saudi Arabian Riyal.

• "SEC" refers to the U.S Securities and Exchange Commission.

• "shares" refers to ordinary shares, par value $1.00, of the Company.

• "tons" refers to metric tons; one metric ton is equal to 1,000 kilograms, 2,204.62 pounds, or 1.102

  U.S. (short) tons.

• "UK" refers to the United Kingdom.

• "U.S. dollars", "US$", "USD" or "$" each refers to the United States dollar.

  ‌PRESENTATION OF CERTAIN FINANCIAL AND OTHER INFORMATION

  Accounting Principles

  We prepare our consolidated financial statements in accordance with IFRS as issued by the IASB, and in accordance with IFRS, as adopted by the EU. IFRS differs in certain significant aspects from generally accepted accounting principles in the United States, commonly referred to as U.S. GAAP. Additionally, this annual report includes certain non-IFRS alternative performance measures such as EBITDA, Net cash/debt position and Free Cash Flow. See Exhibit 3 for more details on these alternative performance measures.

  We publish consolidated financial statements presented in increments of a thousand U.S. dollars. This annual report includes our audited consolidated statements of financial position as of December 31, 2025 and 2024, and the related consolidated income statements, consolidated statements of comprehensive income, consolidated statements of changes in equity and consolidated statements of cash flows for each of the three years in the period ended December 31, 2025, including the related notes (collectively referred to as the "consolidated financial statements").

  Rounding

  Certain monetary amounts, percentages and other figures included in this annual report have been subject to rounding adjustments. Accordingly, figures shown as totals in certain tables may not be the arithmetic aggregation of the figures that precede them, and figures expressed as percentages in the text may not total 100% or, as applicable, when aggregated may not be the arithmetic aggregation of the percentages that precede them.

  Our Internet Website is Not Part of this Annual Report

  We maintain an Internet website at https://www.tenaris.com. Information contained in or otherwise accessible through our Internet website is not a part of this annual report. All references in this annual report to this Internet site are inactive textual references to these URLs, or "uniform resource locators" and are for informational reference only. We assume no responsibility for the information contained on our Internet website.

  This annual report has been prepared in accordance with the European Single Electronic Format ("ESEF"). This version of the annual report is the only authoritative version and is available on the Luxembourg Stock Exchange website: https://my.luxse.com/FIRST.

  Industry Data

  Unless otherwise indicated, industry data and statistics (including historical information, estimates or forecasts) in this annual report are contained in or derived from internal or industry sources believed by Tenaris to be reliable. Industry data and statistics are inherently predictive and are not necessarily reflective of actual industry conditions. Such statistics are based on market research, which itself is based on sampling and subjective judgments by both the researchers and the respondents, including judgments about what types of products and transactions should be included in the relevant market. In addition, the value of comparisons of statistics for different markets is limited by many factors, including that (i) the markets are defined differently,

  (ii) the underlying information was gathered by different methods and (iii) different assumptions were applied in compiling the data. Such data and statistics have not been independently verified, and the Company makes no representation as to the accuracy or completeness of such data or any assumptions relied upon therein.

  ‌CAUTIONARY STATEMENT CONCERNING FORWARD-LOOKING STATEMENTS

  This annual report and any other oral or written statements made by us to the public may contain "forward-looking statements" within the meaning of and subject to the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995. This annual report contains forward-looking statements, including with respect to certain of our plans and current goals and expectations relating to Tenaris's future financial condition and performance.

  Sections of this annual report that by their nature contain forward-looking statements include, but are not limited to, "Risk Factors," "Information on the Company," "Operating and Financial Review and Prospects," "Financial Information," and "Quantitative and Qualitative Disclosure About Market Risk".

  We use words and terms such as "aim", "will likely result", "will continue", "contemplate", "seek to", "future", "objective", "goal", "should", "will pursue", "anticipate", "estimate", "expect", "project", "intend", "plan", "believe", and words and terms of similar substance to identify forward-looking statements, but they are not the only way we identify such statements. All forward-looking statements are management's present expectations of future events and are subject to a number of factors and uncertainties that could cause actual results to differ materially from those described in the forward-looking statements.

  These factors include the risks related to our business and industry discussed under "Risk Factors", including among them, the following:

• our ability to implement our business strategy and to adapt it adequately to tariffs and other changes in laws and regulations and, over the longer term, the energy transition;

• our ability to grow through acquisitions, joint ventures and other investments, or integrate newly acquired businesses or assets;

• our ability to provide value added products and services and price such products and services in accordance with our strategy;

• trends in the levels of investment in oil and gas exploration and drilling worldwide;

• the competitive environment or level of consolidation in our business and our industry;

• the impact of climate change legislation, including increasing regulatory requirements and extensive technology and market changes aimed at transitioning to a lower-carbon economy and reducing GHG emissions;

• the physical risks resulting from climate change, including natural disasters, increased severity of extreme weather events, chronic climate changes and long-term shifts in weather patterns;

• our ability to absorb cost increases and to secure supplies of essential raw materials and energy;

• our ability to adjust fixed and semi-fixed costs to fluctuations in product demand;

• the impact of the world's economy on the energy sector in general, or our business and operations;

  and

• general macroeconomic conditions, including renewed inflation or high inflation rates, inflation containment measures and foreign exchange measures, as well as, international conflicts, particularly the escalation of the Middle East conflict, public health epidemics and other political, social, or economic conditions and developments in the countries in which we operate or distribute pipes.

  By their nature, certain disclosures relating to these and other risks are only estimates and could be materially different from what actually occurs in the future. As a result, actual future gains or losses or other occurrences or developments that may affect our financial condition and results of operations could differ materially from those that have been estimated. You should not place undue reliance on forward-looking statements, which speak only as of the date of this annual report. Except as required by law, we are not under any obligation, and expressly disclaim any obligation to, update or alter any forward-looking statements, whether as a result of new information, future events or otherwise.

  ‌RISK FACTORS

  You should carefully consider the risks and uncertainties described below, together with all other information contained in this annual report, before making any investment decision. Any of these risks and uncertainties could have a material adverse effect on our business, revenues, financial condition and results of operations, which could in turn affect the price of shares and ADSs.

  ‌Risks Relating to our Business and Industry

  Sales and profitability may fall as a result of downturns in the international price of oil and gas and other factors and circumstances affecting the oil and gas industry

  We are a global steel pipe manufacturer primarily focused on manufacturing products and providing related services for the oil and gas industry, which is a major consumer of high-specification steel pipe products worldwide. Demand for steel pipe products for the oil and gas industry has been historically volatile and depends primarily on the number of wells drilled, completed and reworked, and on well depth, length and drilling conditions. Exploration, development and production activity and related capital spending by oil and gas companies, including national oil companies, depends primarily on current and expected oil and gas prices and are sensitive to expectations for economic growth and resulting oil and gas demand. Several factors, such as the supply and demand for oil and gas, the development and availability of new drilling technology, political and global economic conditions, and government regulations affect these prices. Specific factors that have had or are likely to have an impact on oil and gas prices and drilling activity include:

• developments in drilling technology, which have allowed producers in the United States, Canada and other countries to increase production from their reserves of tight oil and shale gas in response to changes in market conditions more rapidly than in the past;

• consolidation, drilling efficiencies and productivity gains in the U.S. oil and gas industry, which have impacted prices and overall drilling activity in North America; and

• government initiatives to reduce GHG emissions, which could affect oil and gas prices. For more information on risks relating to climate change regulations, see "Risk Factors - Risks Relating to Our Business and Industry - Climate change legislation, evolving ESG regulatory frameworks and the transition to a lower-carbon economy may reduce demand for our products and services, increase our costs and capital expenditures, and adversely affect our competitiveness, financial condition and reputation".

When oil and gas prices fall, producers generally reduce production and exploration spending and purchase fewer steel pipe products. Major oil-and gas-producing nations and companies have frequently collaborated to balance oil supply (and thus prices) in the international markets, including through the OPEC, and the expanded group of producer countries known as OPEC+. Many of our customers are state-owned companies in OPEC member countries, and OPEC plays a significant role in trying to counter falling prices.

Adverse economic, political and security conditions in the countries where we operate or sell our products and services, as well as armed conflicts, geopolitical tensions and related sanctions, may disrupt our operations, reduce demand and adversely affect our revenues, profitability and financial condition

We have significant operations and sales in multiple countries, and our business is exposed to political, economic, social, regulatory and security developments that are unpredictable and may vary significantly from jurisdiction to jurisdiction. These developments and risks include trade restrictions, inflation, devaluation, exchange controls, changes (including retroactive) in tax regimes, price controls, delays or denials of governmental approvals, labor disruptions, energy shortages, civil unrest, criminal violence, armed conflicts, sanctions and other geopolitical events. The occurrence of any of these events could disrupt our manufacturing operations or supply chain, reduce demand for our products and services, and adversely affect our financial condition and results of operations.

In particular, we have significant operations in Argentina and Mexico and are exposed to heightened economic, political and regulatory risks in those countries. Argentina has been historically subject to macroeconomic and political volatility, high levels of inflation, currency controls and devaluation, energy supply constraints and regulatory uncertainty. Such conditions have in the past, and may in the future, adversely affect our costs, margins, operations, ability to access foreign currency, repatriate funds or finance

investments. For additional information on current Argentine exchange controls and restrictions, see "Legal and Financial Information - Additional Information - Exchange Controls".

In Mexico, governmental influence over the economy and the energy sector, payment delays by state-owned customers, labor disruptions and changes in energy and regulatory frameworks could adversely affect our operations, cash flows and profitability. In particular, we maintain a strong, longstanding relationship with Petróleos Mexicanos ("Pemex"), a significant crude oil and condensate producer and one of our largest customers. Over the past years, Pemex has delayed payments beyond the agreed-upon due dates, resulting in a significant credit exposure to Pemex, although this was significantly reduced at the end of 2025. If Pemex defaults on its payment obligations or our exposure to Pemex increases to excessive levels, our revenues and profitability could be adversely affected. Our Mexican operations could also be affected by criminal violence, primarily due to the activities of drug cartels and related to organized crime which has been increasing in Mexico over the last years. Although the Mexican government has implemented various security measures and has strengthened its military and police forces, drug-related crime continues to exist in Mexico. Our business may be materially and adversely affected by these activities, their possible escalation and the violence associated with them.

In addition, armed conflicts and geopolitical tensions, particularly in the Middle East, and related sanctions, may disrupt global trade flows and sales to affected customers, increase energy and raw-material costs, affect supply availability, restrict transactions with certain counterparties, result in operational disruptions or asset impairments, and affect our delivery commitments, adversely affecting our results of operations and financial condition. 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 supply is shipped, resulting in extreme volatility of energy 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. We maintain significant industrial operations and customer relationships in the Middle East. A prolonged conflict or an escalation of hostilities in the region could disrupt our operations at these facilities, impair our ability to fulfill customer orders, restrict employee mobility, damage physical infrastructure, and hinder supply of raw materials, semi-finished steel and other inputs to our 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 Hormuz Strait could significantly increase oil prices and fuel broader inflation, slow global economic activity and reduce demand for our products. The imposition of additional sanctions targeting Iran-linked maritime networks and the potential for expanded trade restrictions may further constrain our sourcing alternatives and increase compliance costs.

Climate change legislation, evolving ESG regulatory frameworks and the transition to a lower-carbon economy may reduce demand for our products and services, increase our costs and capital expenditures, and adversely affect our competitiveness, financial condition and reputation

Regulatory, investor, customer and social scrutiny of GHG emissions and climate-related impacts has increased globally. Governments and regulators in multiple jurisdictions have adopted, or are considering adopting, laws, regulations and policies aimed at reducing emissions, promoting the transition to a lower-carbon economy and expanding climate and sustainability-related disclosures. Government initiatives include carbon taxes or carbon-pricing systems (including the CBAM), "cap-and-trade" systems (like the ETS) and measures promoting renewable energy sources, or electric vehicles. These regulations are complex, evolving and, in some cases, inconsistent or conflicting across jurisdictions, increasing compliance burdens, costs and legal risks.

Climate-related regulatory uncertainty, including changes to disclosure regimes and emissions-related requirements, may further increase compliance complexity and costs. In addition, governments may adopt more stringent or abrupt policy, legal, technological or market measures to meet climate objectives.

We provide products and services to the oil and gas industry, which accounts for a significant portion of global GHG emissions. Existing and future climate-related legislation, carbon pricing mechanisms, emissions-reporting obligations, restrictions on fossil fuel development, government incentives for alternative energy sources and increasing competitiveness of renewable energy may reduce demand for oil and natural gas and, in turn, for our products and services. These developments may increase operating and compliance costs, require additional capital expenditures and adversely affect our market position.

Shifts in stakeholder expectations regarding climate-related performance and disclosures, and our ability to meet evolving regulatory, investor, customer and employee demands, may adversely affect our reputation, access to capital and results of operations.

The physical risks resulting from climate change, including extreme weather conditions and shifts in weather patterns, have in the past, and may in the future, adversely affect our operations and financial results

Our business has been, and in the future could be, affected by severe weather in areas where we operate, which could materially affect our operations and financial results. Extreme weather conditions and natural disasters such as hurricanes, extreme wind, fires, flooding or coastal storm surges have resulted, and may in the future result, in the shutdown of our facilities, evacuation of our employees, and activity disruptions at our clients' well-sites or in our supply chain.

Chronic physical risks associated with climate change, including changes in precipitation patterns and increases in average temperatures and sea levels, may increase operating costs and capital expenditures resulting from facility damage, supply constraints, higher insurance costs or reduced availability of insurance, reduced production capacity, and asset impairments or early retirement. Occurrence of these risks could adversely affect our financial condition, results of operations and cash flows.

Competition in the global market for steel pipe products may cause us to lose market share and hurt our sales and profitability

The global market for steel pipe products is highly competitive; key factors include price, quality, service and technology. Over the past two decades, substantial investments, especially in China but also in the United States and the Middle East, have increased production capacity of seamless steel pipe products, without a corresponding increase in demand, resulting in significant excess capacity, particularly for "commodity" or standard product grades. Production capacity for more specialized products has also increased. At the same time, the high capital costs and long lead times of the most complex projects, particularly deepwater, have slowed new developments in a context of lower and more volatile oil prices. Despite our efforts to differentiate our products and services, the competitive environment is expected to remain intense in the coming years and our ability to achieve effective competitive differentiation, vertically integrate, and provide value added services, will be critical.

In addition, unfairly traded steel pipe imports may affect markets in which Tenaris produces and sells, and we can give no assurance with respect to the imposition or maintenance of antidumping duties and tariffs or the effectiveness of any such measures.

Our sales may be affected as a result of antidumping and countervailing duty proceedings or by the imposition of other import restrictions or local content requirements

Because of the global nature of our operations, we export and import products from several countries and, in many jurisdictions, we supplement domestic production with imported products. We import OCTG and other products from our facilities in other countries to complement our significant and growing production in the United States. From time to time, local producers seek the imposition of import restrictions or the initiation of antidumping or countervailing duty proceedings. Antidumping or countervailing duty proceedings, any resulting penalties or any other form of import restriction can impede or make it more costly and restrict our access to important export markets for our products, thereby adversely impacting on our sales or limiting our opportunities for growth. For example, in October 2021, the U.S. Department of Commerce ("DOC") initiated antidumping duty investigations of OCTG imports from Argentina, Mexico, and Russia, which resulted in the payment of certain antidumping duty deposits, in the context of an ongoing process.

Although the applicable antidumping duties were subsequently lowered, the determination of the final level of duties for any given period remains subject to uncertainty and the time taken to receive any refunds is subject to delays. For more information on this matter, please refer to note 27 "Contingencies, commitments and restrictions on the distribution of profits" to our audited consolidated financial statements included in this annual report.

In addition, several jurisdictions of significance within our business, such as Saudi Arabia, Brazil, Indonesia, Nigeria and the United Arab Emirates, have imposed or expanded local content requirements. Other mechanisms, such as the CBAM, could have a similar impact. For more information, see "Risk Factors - Risks Relating to Our Business and Industry - The cost of complying with environmental regulations and potential environmental and product liabilities may increase our operating costs and adversely affect our business,

financial condition and results of operations". If countries impose or expand local content requirements or put in place regulations limiting our ability to import certain products, our competitive position could be negatively affected. Therefore, if any of these risks materialize, we may not continue to compete effectively against existing or potential producers and preserve our current shares of geographic or product markets, and increased competition may have a material impact on the pricing of our products and services, which could in turn adversely affect our revenues, profitability and financial condition.

Our sales may also be affected as a result of tariffs and other international trade regulations

We are subject to tariffs and trade and customs laws and regulations governing shipment of goods and services across international borders. In addition, the EU, the United States and other countries impose requirements, recordkeeping and reporting obligations and, in certain cases, economic sanctions, to control, restrict or prohibit the import and export of certain goods and services. Certain governments have also imposed economic sanctions against certain countries, persons or other entities, such as sanctions that restrict or prohibit international commercial transactions involving Iran, Russia, Syria and Venezuela, and their citizens or companies. Similarly, we are subject to the U.S. anti-boycott laws. International trade laws and regulations are complex and frequently changing, and they may be enacted, amended, enforced or interpreted in a manner that could materially impact our operations. For example, tariffs imposed by the United States on steel imports and other tariffs, including potential retaliatory countermeasures from other countries or trade partners, are affecting market prices and dynamics, supply chains, and cost structures, and could result in a prolonged or escalated trade war. For more information on U.S. tariffs on steel imports, please see note 37 "Tariffs on steel and other imports in the United States and Canada" to our audited consolidated financial statements included in this annual report.

Increases in the cost of raw materials, energy and other costs, limitations or disruptions to the supply of raw materials and energy, and price mismatches between raw materials and our products may hurt our profitability

The manufacture of seamless steel pipe products requires substantial amounts of steelmaking raw materials and energy; welded steel pipe products, in turn, are processed from steel coils and plates. The availability and pricing of a significant portion of the raw materials, including steel coils and plates, and energy we require are subject to supply and demand conditions, which can be volatile, and to tariffs and other government regulations, which can affect continuity of supply and prices. In addition, disruptions, restrictions or limited availability of energy resources in markets where we have significant operations could lead to higher costs of production and eventually to production cutbacks at our facilities in such markets. For example, the Russia-Ukraine war resulted in a spike in European energy costs, and, beginning in early 2024, we experienced some delays in the delivery times to our customers in relation to orders that had to be diverted because of the ongoing shipping disruption in the Red Sea. More recently, the escalation of the Middle East conflict is affecting energy costs, particularly in Europe, and disrupting shipping and deliveries to regional customers.

For more information, please see "Risk Factors - Risks Relating to Our Business and Industry - Adverse economic, political and security conditions in the countries where we operate or sell our products and services, as well as armed conflicts, geopolitical tensions and related sanctions, may disrupt our operations, reduce demand and adversely affect our revenues, profitability and financial condition".

At any given time, we may be unable to obtain an adequate supply of critical raw materials with price and other terms acceptable to us. The availability and prices of raw materials may also be negatively affected by new laws and regulations, including import controls, sanctions and other trade restrictions, allocation by suppliers, interruptions in production, accidents or natural disasters, armed conflicts, chronic climate change, changes in exchange rates, worldwide price fluctuations, and the availability and cost of transportation. Raw material and energy prices could also be affected by the introduction of carbon prices or taxes, or as a result of changes in production processes, such as an increased use of metal scrap, adopted by steelmaking companies seeking to reduce carbon emissions. In addition, we may not be able to recover, partially or fully, increased costs of raw materials and energy through increased selling prices for our products, or it may take an extended period of time to do so, and limited availability could force us to curtail production, which could adversely affect our sales and profitability.

Our results of operations and financial condition could be adversely affected by low levels of capacity utilization or failure to attract or retain a qualified workforce

Like other manufacturers of steel-related products, we have fixed and semi-fixed costs (e.g., labor and other operating and maintenance costs) that cannot adjust rapidly to fluctuations in product demand for several reasons, including operational constraints and regulatory restrictions. If demand for our products falls

significantly, as was the case during past oil crises, or if we are unable to operate due to, for example, governmental measures or unavailability of workforce, as occurred during the COVID-19 pandemic, these costs may adversely affect our profitability and financial condition. Temporary suspensions of operations or closure of facilities in respect to these developments generally lead to layoffs of employees, which may in turn give rise to labor conflicts and impact operations. Cost containment measures may also affect profitability and result in restructuring charges and asset impairments.

In addition, increasing adoption of artificial intelligence and automation technologies in steel manufacturing and oilfield equipment production, maintenance and logistics may materially affect workforce needs, requiring reskilling and redeployment of employees, creating competition for artificial intelligence ("AI") skilled talent, and potentially reducing or eliminating certain roles; our inability to manage these transitions effectively could adversely affect productivity, employee relations, safety, and costs.

In turn, in times of economic growth and high demand for our products we may not be able to retain qualified workforce or hire additional employees soon enough. Adoption of AI-enabled systems for inspection, welding, non-destructive testing, quality control, inventory management and predictive maintenance across our facilities and supply chain may also give rise to labor relation challenges, including resistance to changes in job content, demands for retraining or wage adjustments, and increased scrutiny in collective bargaining. Evolving laws and regulations governing the use of AI in the workplace, including requirements related to transparency, data privacy, bias and worker surveillance, could increase compliance costs and constrain deployment, and failure to comply could result in investigations, litigation or penalties. Competition for personnel with relevant AI, data and automation skills may intensify, increasing labor costs and affecting optimization initiatives.

Moreover, certain consequences of climate change, such as shifts in customer preferences, stigmatization of our industry or failure to respond to shareholder demands for climate-related measures could negatively impact workforce management and planning, adversely affecting employee attraction and retention.

If we do not successfully implement our business strategy, including through acquisitions, strategic partnerships and capital investments, our growth, competitive position and profitability may suffer

We plan to continue implementing our business strategy of consolidating our position as a leading global supplier of integrated product and service solutions to the energy and other industries and adapting to the energy transition by reducing the carbon emissions in our operations and developing and supplying products and services for low-carbon energy applications, while pursuing strategic investment opportunities. Any component of this strategy could cost more than anticipated (including due to increasing regulatory requirements aimed at transitioning to a lower-carbon economy), may not be successfully implemented or could be delayed or abandoned. For example, we may fail to create sufficient differentiation in our Rig Direct® services to offset the added costs of providing such services, or be unable to find suitable investment opportunities, including acquisition targets that enable us to continue to grow and maintain or improve our competitive position.

Assessments of potential acquisitions, joint ventures, partnerships and capital investments necessarily rely on assumptions regarding timing, profitability, market conditions and customer behavior that may prove incorrect. Our past or future acquisitions, significant investments and alliances may not perform in line with expectations and could adversely affect our operations and profitability. Integration of acquired businesses can place new demands on our organization and personnel, disrupt ongoing activities and divert management attention. Moreover, we may acquire assets unrelated to our core business and may be unable to integrate them effectively or divest them on favorable terms.

These transactions are also subject to scrutiny by governmental authorities, including antitrust and consumer-protection authorities. The costs of complying with authorization or investigation procedures may be significant. Authorities are examining the effects of acquisitions more closely and may deny authorizations, impose conditions that may result in significant costs or deprive Tenaris of the advantages and expected synergies of acquisitions, or initiate investigation upon challenges brought by third parties. Challenges to acquisitions or other investments, and failure to obtain, or conditions imposed for the granting of, authorizations may prevent or delay transactions, which could have an adverse effect on our financial condition and results of operations.

Even if we successfully implement our business strategy, it may not yield the expected results, or decisions by our joint venture partners may frustrate our initiatives. External factors -such as market volatility, shifts in customer capital spending, supply chain disruptions and the uncertain pace of the energy transition- could

undermine anticipated benefits. Increased costs to decarbonize operations and develop new products, misallocated capital, or failure to realize anticipated synergies could harm our growth, competitive position, and profitability.

Disruptions to our manufacturing processes could adversely impact our operations, affect customer service levels or our reputation, or expose us to liability and, consequently, adversely affect our financial results

Our steel pipe manufacturing processes depend on the operation of critical steelmaking equipment, such as EAF, continuous casters, rolling mills, heat treatment and various operations that support them, such as our power generation facilities. Despite the investments we make to maintain critical production equipment, such equipment may incur downtime as a result of unanticipated failures or other events, such as fires, explosions, floods, earthquakes, accidents and severe weather conditions.

Similarly, natural disasters or severe weather conditions, including those related to climate change, could significantly damage our production facilities and general infrastructure or affect the normal course of business. For example, our Mexican production facility in Veracruz is located in a region prone to earthquakes, and our Bay City facility in Texas, United States is located in an area prone to strong winds and hurricanes, and occasional floods. More generally, changing weather patterns and climatic conditions in recent years have added to the unpredictability and frequency of natural disasters. For more information on the risks associated with climate-change, see "Risk Factors - Risks Relating to Our Business and Industry - The physical risks resulting from climate change, including extreme weather conditions and shifts in weather patterns, have in the past, and may in the future, adversely affect our operations and financial results".

Our operations may also be adversely affected as a result of work stoppages or other labor conflicts, as was the case, in the past, when our operations in Mexico were disrupted due to union-led stoppages resulting from an internal dispute within the local union. In addition, in some of the countries in which we have significant production facilities (e.g., Argentina and Brazil), significant inflationary pressures and higher tax burdens could increase labor demands and could eventually generate higher levels of labor conflicts, which may result in operational disruptions.

Epidemics and other public health crises may also disrupt our operations, as was the case during 2020 as a result of the COVID-19 outbreak when some of our facilities or production lines were closed or shutdown.

Some of the previously described emergency situations could result, and in some cases have resulted, in damage to property, delays in production or shipments and death or injury to persons.

Any of the foregoing could expose us to liability and affect our reputation. To the extent that lost production or delays in shipments cannot be compensated for by unaffected facilities, such events could have an adverse effect on our profitability and financial condition. Additionally, we do not carry business interruption insurance, and the insurance we maintain for property damage and general liability may not be adequate or available to protect us under such events, its coverage may be limited, or the amount of our insurance may be less than the related loss. For more information on our insurance coverage, see "Information on the Company - Business overview - Insurance".

Our results of operations and financial condition could be adversely affected by movements in exchange rates. In addition, particularly as a consequence of deteriorating market conditions, we may be required to record a significant charge to earnings if we must reassess our goodwill or other assets as a result of changes in assumptions underlying the carrying value of certain assets

As a global company, we manufacture and sell products throughout the world and a portion of our business is carried out in currencies other than the U.S. dollar, which is the Company's functional and presentation currency. As a result, we are exposed to foreign exchange rate risk. Changes in currency values and foreign exchange regulations could adversely affect our financial condition and results of operations. For information on our foreign exchange rate risk, please see "Legal and Financial Information - Quantitative and Qualitative Disclosure About Market Risk".

In addition, a significant portion of our assets are subject to amortization. These assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. Intangible assets with indefinite useful life, including goodwill, are subject to impairment tests following IAS 36. We may be required to record a significant charge to earnings if we must reassess our

goodwill or other assets as a result of changes in assumptions underlying the carrying value of certain assets, particularly as a consequence of deteriorating market conditions.

Changes in applicable tax regulations and resolutions of tax disputes could negatively affect our financial results

We are subject to tax laws and regulations in multiple jurisdictions, and the integrated nature of our global operations may give rise to conflicting claims by tax authorities, including with respect to transfer pricing and the allocation of taxable profits among jurisdictions. Although many jurisdictions provide dispute resolution mechanisms under double taxation treaties, such processes may be lengthy, uncertain and may not fully eliminate double taxation.

Tax authorities worldwide have increased scrutiny of multinational groups, and ongoing changes to international tax frameworks, including initiatives led by the OECD, the European Union and other jurisdictions, have increased complexity, compliance obligations and the risk of tax disputes. We are subject to global minimum taxation regimes, including Pillar Two rules, which may result in additional tax liabilities, increased compliance costs and greater exposure to interpretation differences among tax authorities. The implementation, coordination and interaction of these regimes across jurisdictions remain evolving and uncertain.

Further changes in tax laws, regulations or their interpretation or enforcement, including those related to evolving international tax initiatives, could require adjustments to our organizational structure, increase the risk of audits and disputes, and result in additional taxes, penalties or interest. Any of these developments could adversely affect our profitability, financial condition and cash flows.

Failure to comply with anti-corruption laws and regulations could subject us to investigations, fines, penalties, litigation and reputational harm, and could adversely affect our sales, profitability and financial condition

We operate globally, including in jurisdictions with elevated corruption risks. Despite our commitment to conduct business ethically and in compliance with applicable anti-corruption laws, including the FCPA, the UK Bribery Act, and similar laws in other jurisdictions, we face the risk that our employees, agents, representatives, affiliates or other associated persons may engage in conduct that violates such laws. Many anti-corruption regimes impose strict liability on companies for the actions of third parties acting on their behalf, and we cannot assure that all past or future violations, including at acquired businesses, will be detected or prevented. Actual or alleged violations of anti-corruption laws could result in governmental investigations, significant management distraction, substantial fines, penalties or other sanctions, private litigation, increased compliance costs, and reputational damage, which could adversely affect our operations, revenues, profitability and financial condition.

For information on matters related to the Company Business Conduct Compliance Program, please refer to our website on the matter https://www.tenaris.com/en/sustainability/governance-and-ethics/. Information contained in or otherwise accessible through our Internet website is not a part of this annual report. For information on matters related to the Petrobras-related proceedings and claims, please see note 27 "Contingencies, commitments and restrictions on the distribution of profits" to our audited consolidated financial statements included in this annual report.

The cost of complying with environmental regulations and potential environmental and product liabilities may increase our operating costs and adversely affect our business, financial condition and results of operations

We are subject to extensive and evolving environmental, health and safety laws and regulations in the jurisdictions in which we operate, including those relating to hazardous materials, air emissions, water discharges, and waste management. Environmental requirements have become increasingly complex, stringent, and costly to implement, vary significantly across jurisdictions, and may place us at a competitive disadvantage relative to competitors operating in jurisdictions with less stringent standards. Compliance costs and the impact of future regulatory changes are often uncertain and may require significant capital expenditure or remediation costs.

Certain environmental laws impose strict, joint and several liability for environmental damage, remediation, and threats to public health, regardless of fault or compliance at the time of the activity. As a result, we may be exposed to liabilities arising from environmental incidents, conditions, or activities caused by third parties or from historical operations. Environmental incidents or accidents, even if promptly addressed, could result in regulatory actions, remediation obligations, reputational harm and operational disruptions.

In addition, trade-related environmental measures, such as carbon pricing and border adjustment mechanisms, including the CBAM, may increase compliance costs, administrative burdens and the cost of accessing certain markets.

Our oil and gas casing, tubing, and line pipe products are sold primarily for use in oil and gas drilling, gathering, transportation, processing and power generation facilities, which are subject to inherent risk. Product defects or failures, including well failures, line pipe leaks, blowouts, bursts and fires, could result in personal injury, property damage, environmental pollution, production losses and related liabilities, adversely affecting our results of operations and financial condition.

We warrant our products in accordance with customer specifications and, as we expand our service offerings, may be required to warrant that products and services are fit for their intended purpose. Actual or alleged defects in our products or services could result in warranty or product liability claims, including claims for damages or losses suffered by customers.

Our insurance coverage may be limited, unavailable or insufficient to cover all potential claims, including in cases of gross negligence or willful misconduct. In addition, our sales of tubes and components to the automotive industry expose us to product liability risks, including potential liability for vehicle recalls, which could adversely affect our financial condition and results of operations.

Limitations on our ability to protect our intellectual property rights, including our trade secrets, could adversely affect our competitive advantage and financial results

Some of our products, services, and processes are protected by patents, pending patent applications, or trade secrets. Our business may be adversely affected if such protections are unenforceable, insufficient or denied, or if our trade secrets are not adequately protected. In addition, competitors may independently develop similar technologies without infringing our intellectual property, which could adversely affect our revenues, financial condition, results of operations, and cash flows.

Cyberattacks could have a material adverse impact on our business and results of operations

We rely heavily on information systems, and cyber threats are persistent, evolving, and often beyond our control. Despite significant investments in security, monitoring, and response, we experience cyber incidents in the normal course of business. The growing availability and use of artificial intelligence amplifies adversarial capabilities and increases the likelihood, scale, and sophistication of attacks. There can be no assurance that our defenses will prevent or limit the effects of cyber incidents. We remain vulnerable to unauthorized access, loss, destruction, corruption, or misuse of data; compromise of credentials and identities; system and network outages; programming or employee errors; and dishonest or malicious behavior. Threats may also arise from third parties and the broader ecosystem, including suppliers, service providers, and customers, where we do not control the effectiveness of their safeguards.

Supply chain complexity heightens the risk of propagation across Tenaris's environment. If critical third parties are affected, or if our own safeguards are circumvented or breached, consequences could include disruption of operations and manufacturing, loss of access to critical systems and financial reporting, compromise of intellectual property and customer data, failure to meet customer requirements, reputational damage, regulatory investigations, fines and penalties (including for personal data protection and breach notification), safety and environmental impacts, and other financial losses. The dynamic threat landscape may also require continued increases in resources to enhance prevention, detection, response, and recovery capabilities.

We do not currently maintain standalone cyber insurance, and existing property and general liability policies may not adequately cover cyber-related losses. Investigations and remediation following an incident can be prolonged, during which the full scope of harm may be unknown and certain issues may recur. Additionally, failure to timely monitor and address technology obsolescence could increase costs and operational risk.

Regulatory developments, including restrictions on ransomware payments and related facilitation, may limit our options for responding to certain attacks.

For more information on cybersecurity, please refer to "Legal and Financial Information - Cybersecurity".

‌Risks Relating to our Structure

Our dividend payments depend on the results of operations and financial condition of its subsidiaries and could be restricted by legal, contractual or other limitations or tax changes

The Company is a holding company and conducts all its operations through subsidiaries. Dividends or other intercompany transfers of funds from those subsidiaries are our primary source of funds to pay its expenses, debt service and dividends and to repurchase shares or ADSs.

The ability of our subsidiaries to pay dividends and make other payments to us will depend on their results of operations and financial condition. If earnings and cash flows of our operating subsidiaries are substantially reduced, the Company may not be in a position to meet its operational needs or to pay dividends. In addition, such dividends and other payments could be restricted by applicable corporate and other laws and regulations, including those imposing foreign exchange controls or restrictions on the repatriation of capital or the making of dividend payments, and agreements and commitments of such subsidiaries.

The Company's ability to pay dividends to shareholders is subject to legal and other requirements and restrictions in effect at the holding company level. For example, the Company may only pay dividends out of net profits, retained earnings and distributable reserves and premiums, each as defined and calculated in accordance with Luxembourg law and regulations. In addition, the Company's dividend distributions (which are currently imputed to a special tax reserve and are therefore not subject to Luxembourg withholding tax) may be subject to Luxembourg withholding tax if current Luxembourg tax law were to change.

Our controlling shareholder may be able to take actions that do not reflect the will or best interests of other shareholders

As of December 31, 2025, San Faustin beneficially owned 66.13% of the Company's issued share capital, and 70.07% of the voting rights. Rocca & Partners Stichting Administratiekantoor Aandelen San Faustin ("RP STAK") holds voting rights in San Faustin sufficient to control San Faustin. As a result, RP STAK is indirectly able to elect a substantial majority of the members of the Company's board of directors and has the power to determine the outcome of most actions requiring shareholder approval, including, subject to the requirements of Luxembourg law, the payment of dividends. The decisions of the controlling shareholder may not reflect the will or best interest of other shareholders. In addition, the Company's articles of association permit the Company's board of directors to waive, limit or suppress preemptive rights in certain cases.

Accordingly, the Company's controlling shareholder may cause its board of directors to approve in certain cases an issuance of shares for consideration without preemptive rights, thereby diluting the minority interest in the Company. See "Risk Factors - Risks Relating to shares and ADSs - Holders of shares and ADSs in the United States may not be able to exercise preemptive rights in certain cases".

‌Risks Relating to shares and ADSs

Holders of shares or ADSs may not have access to as much information about the Company as they would in the case of a U.S. domestic issuer

There may be less publicly available information about the Company than is regularly published by or about

U.S. domestic issuers. Also, corporate and securities regulations governing Luxembourg companies may not be as extensive as those in effect in other jurisdictions and U.S. securities regulations applicable to foreign private issuers, such as the Company, differ in certain respects from those applicable to U.S. domestic issuers. Furthermore, IFRS, the accounting standards in accordance with which the Company prepares its consolidated financial statements, differ in certain material aspects from U.S. GAAP. For a summary of the significant ways in which the Company's corporate governance practices differ from the corporate governance standards required for domestic companies by the New York Stock Exchange ("NYSE"), see "Information on the Company - Corporate Governance Statement - Summary of differences with NYSE standards".

Holders of ADSs may not be able to exercise, or may encounter difficulties in the exercise of, certain rights afforded to shareholders

Certain shareholders' rights under Luxembourg law, including the rights to participate and vote at general meetings of shareholders, to include items on the agenda for the general meetings of shareholders, to receive dividends and distributions, to bring actions, to examine our books and records and to exercise appraisal rights may not be available to holders of ADSs, or may be subject to restrictions and special procedures for their exercise, as holders of ADSs only have those rights that are expressly granted to them in the deposit agreement. The Depositary, through its custodian agent, is the registered shareholder of the deposited shares underlying the ADSs, and therefore only the Depositary can exercise the shareholders' rights in connection with the deposited shares. For example, if the Company makes a distribution in the form of securities, the Depositary is allowed, at its discretion, to sell the right to acquire those securities on behalf of the shareholders and to instead distribute the net proceeds to them. Also, under certain circumstances, such as the Company's failure to provide the Depositary with voting materials on a timely basis, you may not be able to vote at general meetings of shareholders by giving instructions to the Depositary. If the Depositary does not receive voting instructions from the holder of ADSs by the prescribed deadline, or the instructions are not in proper form, then the Depositary shall deem such holder of ADSs to have instructed the Depositary to vote the underlying shares represented by ADSs in favor of any proposals or recommendations of the Company (including any recommendation by the Company to vote such underlying shares on any given issue in accordance with the majority shareholder vote on that issue), for which purposes the Depositary shall issue a proxy to a person appointed by the Company to vote such underlying shares represented by ADSs in favor of any proposals or recommendations of the Company. Under the ADS deposit agreement, no instruction shall be deemed given and no proxy shall be given with respect to any matter as to which the Company informs the Depositary that (i) it does not wish such proxy given, (ii) it has knowledge that substantial opposition exists with respect to the action to be taken at the meeting, or (iii) the matter materially and adversely affects the rights of the holders of ADSs.

Holders of shares and ADSs in the United States may not be able to exercise preemptive rights in certain cases

Pursuant to Luxembourg corporate law, existing shareholders of the Company are generally entitled to preferential subscription rights (preemptive rights) in the event of capital increases and issues of shares against cash contributions. Under the Company's articles of association, the board of directors has been authorized to waive, limit or suppress such preemptive subscription rights. Notwithstanding the waiver of any preemptive subscription rights, any issuance of shares for cash within the limits of the authorized share capital shall be subject to the preemptive subscription rights of existing shareholders, except (i) any issuance of shares (including without limitation, the direct issuance of shares or upon the exercise of options, rights convertible into shares, or similar instruments convertible or exchangeable into shares) against a contribution other than in cash; and (ii) any issuance of shares (including by way of free shares or at discount), up to an amount of 1.5% of the issued share capital of the Company, to directors, officers, agents, employees of the Company, its direct or indirect subsidiaries or its affiliates (or, collectively, the beneficiaries), including without limitation, the direct issuance of shares or upon the exercise of options, rights convertible into shares or similar instruments convertible or exchangeable into shares, issued for the purpose of compensation or incentive of the beneficiaries or in relation thereto (which the board of directors shall be authorized to issue upon such terms and conditions as it deems fit). For further details, see "Information on the Company -Corporate Governance Statement - Corporate Governance".

Holders of ADSs in the United States may, in any event, not be able to exercise any preemptive rights, if granted, for shares underlying their ADSs unless additional shares and ADSs are registered under the U.S. Securities Act of 1933, as amended, ("Securities Act"), with respect to those rights, or an exemption from the registration requirements of the Securities Act is available. The Company intends to evaluate, at the time of any rights offering, the costs and potential liabilities associated with the exercise by holders of shares and ADSs of the preemptive rights for shares, and any other factors it considers appropriate at the time, and then to make a decision as to whether to register additional shares. The Company may decide not to register any additional shares, requiring a sale by the Depositary of the holders' rights and a distribution of the proceeds thereof. Should the Depositary not be permitted or otherwise be unable to sell preemptive rights, the rights may be allowed to lapse with no consideration to be received by the holders of the ADSs.

It may be difficult to obtain or enforce judgments against the Company outside Luxembourg

The Company is a société anonyme organized under the laws of the Grand Duchy of Luxembourg, and most of its assets are located in other jurisdictions. Furthermore, most of the Company's directors and officers reside in other jurisdictions. As a result, investors may not be able to effect service of process upon the Company or its directors or officers. Investors may also not be able to enforce against the Company or its directors or officers in the investors' domestic courts, judgments predicated upon the civil liability provisions of the domestic laws of the investors' home countries. Likewise, it may be difficult for investors not domiciled in Luxembourg to bring an original action in a Luxembourg court predicated upon the civil liability provisions of other securities laws, including U.S. federal securities laws, against the Company, its directors or its officers. There is also uncertainty with regard to the enforceability of original actions of civil liabilities predicated upon the civil liability provisions of securities laws, including U.S. federal securities laws, outside the jurisdiction where such judgments have been rendered; and enforceability will be subject to compliance with procedural requirements under applicable local law, including the condition that the judgment does not violate the public policy of the applicable jurisdiction.

‌INFORMATION ON THE COMPANY

‌Overview

Tenaris is a leading global manufacturer and supplier of steel pipe products and related services for the world's energy industry and other industrial applications. Our customers include most of the world's leading oil & gas companies, and we operate an integrated network of steel pipe manufacturing, research, finishing and service facilities with industrial operations in the Americas, Europe, the Middle East, Asia and Africa.

Although our operations are mainly focused on serving the oil & gas industry, we supply pipes and tubular components for non-energy applications. We also develop and supply products and services for low-carbon energy applications such as geothermal wells, waste-to-energy (bioenergy) power plants, hydrogen storage and transportation, and carbon capture and storage ("CCS").

Through an integrated global network of R&D, manufacturing, and service facilities, and a team of around 25,000 people worldwide, we work with our customers to meet their needs in a timely manner, delivering the highest levels of product performance and reliability.

‌History and Development of the Company The Company

The Company is a société anonyme organized under the laws of the Grand Duchy of Luxembourg established on December 17, 2001. The Company's registered office is located at 26 Boulevard Royal, 4th Floor, L-2449, Luxembourg. Its agent for U.S. federal securities law purposes is Tenaris Global Services (U.S.A.) Corporation ("TEUS"), located at 2200 West Loop South, Suite 400, Houston, TX 77027.

Tenaris

Tenaris began in 1948 with the formation of Siderca, then Argentina's sole producer of seamless steel pipe products, founded by San Faustin's predecessor. We grew organically in Argentina and then, in the early 1990s, began to evolve beyond this initial base into a global business through a series of strategic acquisitions and investments. As of the date of this annual report, our investments include controlling interests in several manufacturing companies:

• Siat S.A. ("Siat"), an Argentine welded steel pipe manufacturer;

• Tamsa S.A. de C.V. ("Tamsa"), the sole Mexican producer of seamless steel pipe products;

• Dalmine S.p.A. ("Dalmine"), a leading Italian producer of seamless steel pipe products;

• Confab Industrial S.A. ("Confab"), the leading Brazilian producer of welded steel pipe products;

• Algoma Tubes Inc. ("AlgomaTubes"), a Canadian producer of seamless and welded steel pipe products;

• S.C. Silcotub S.A. ("Silcotub"), a leading Romanian producer of seamless steel pipe products;

• Maverick Tube Corporation ("Maverick"), a U.S. producer of seamless and welded steel pipe products;

• Tenaris TuboCaribe Ltda. ("TuboCaribe"), a welded pipe mill producing OCTG products, including the finishing of welded and seamless pipes, line pipe products, and couplings, in Colombia;

• Hydril Company ("Hydril"), a North American manufacturer of premium connection products for oil and gas drilling and production;

• PT Seamless Pipe Indonesia Jaya ("SPIJ"), an Indonesian OCTG processing business with heat treatment and premium connection threading facilities;

• Tenaris Qingdao Steel Pipes Ltd. ("Tenaris Qingdao"), a Chinese producer of premium joints, couplings, and tubular components for airbags;

• Pipe Coaters Nigeria Ltd. ("Pipe Coaters"), a leading company in the Nigerian coating industry;

• Tenaris Bay City Inc. ("Tenaris Bay City"), a state-of-the-art seamless pipe mill in Bay City, Texas;

• Saudi Steel Pipe Company ("SSPC"), a Saudi producer of welded steel pipe products;

• IPSCO Tubulars ("IPSCO"), a North American manufacturer of seamless and welded steel pipes;

• Tenaris Baogang Baotou Steel Pipes, Ltd. ("TBSP"), a Chinese company that owns a premium connection threading facility in Baotou, China, in which we hold a 60% interest;

• Global Pipe Company ("GPC"), a Saudi company that manufactures longitudinal submerged arc welded ("LSAW") pipes;

• Coating businesses in various countries, including Shawcor companies ("TenarisShawcor"), which hold the pipe coating business acquired from Mattr Corporation's ("Mattr");

• Oilfield Services S.A. ("Oilfield Services"), an Argentine company providing oilfield and hydraulic fracturing services; and

• Sucker rods businesses in various countries.

  In addition, we hold a 50% participation in Exiros B.V. ("Exiros"), a Dutch company that manages a network of specialized procurement companies, with our affiliate Ternium S.A. ("Ternium") holding the remaining 50%.

  We also hold strategic interests in:

• Ternium, one of the leading flat steel producers of the Americas with operating facilities in Mexico, Brazil, Argentina, Colombia, the southern United States, and Central America;

• Usinas Siderúrgicas De Minas Gerais S.A. ("Usiminas"), a Brazilian producer of high-quality flat steel products used in the energy, automotive, and other industries; and

• Techgen S.A. de C.V. ("Techgen"), an electric power plant in Mexico.

  In addition, we have established a global network of pipe finishing, distribution and service facilities with a direct presence in most major oil and gas markets, as well as a global network of R&D centers.

  For information on Tenaris's principal capital expenditures and divestitures, see "Information on the Company

  - Business Overview - Capital Expenditure Program".

  ‌Business Overview

  Our business strategy is to consolidate our position as a leading global supplier of integrated product and service solutions to the energy and other industries, and to adapt to the energy transition by reducing the carbon emissions in our operations and by developing and supplying products and services for low-carbon energy applications by:

• pursuing strategic investment opportunities in order to further strengthen our presence in local and global markets and expand our range of products and services;

• expanding our comprehensive range of products and developing new products designed to meet the needs of customers operating in challenging environments, including low-carbon energy applications, such as hydrogen and CCS;

• enhancing our offering of services, including technical, digital, and supply chain integration services designed to enable customers to optimize well planning and well integrity, simplify operations, and reduce overall operating costs; and

• securing an adequate supply of production inputs and reducing the manufacturing costs and carbon intensity of our core products.

  Pursuing strategic investment opportunities and alliances

  We have a solid record of growth through strategic investments and acquisitions. We pursue selective strategic investments and acquisitions to expand our operations and presence in select markets, broaden our range of products and services, enhance our global competitive position, and capitalize on potential operational synergies. At the end of 2023, for example, we acquired the global pipe-coating business of Mattr, which has enhanced our range of pipe-coating technologies and reinforced our capability to provide integrated pipe and coating solutions for offshore pipelines. In 2025, we acquired a scrap processing business in Beaver Falls in Pennsylvania, United States.

  Expanding our product range including developing new products for the energy transition

  We have developed an extensive range of high-value products suitable for most of our customers' operations through our network of specialized R&D facilities and investments in our manufacturing facilities. As our customers expand their operations, we seek to supply high-value products that reduce costs and enable them to operate safely in challenging environments, including low-carbon applications associated with the energy transition.

  As suppliers of tubular products and services to the energy industry, we see the ongoing energy transition as an important opportunity to develop new products and services for potentially fast-growing segments like hydrogen transportation and storage, CCS and geothermal installations. We have developed a range of technologies that are particularly suited for use in hydrogen storage and transportation, where we have seen demand for large, high-pressure vessels used in the build out of hydrogen refueling stations for heavy-duty vehicles and buses in various parts of the world. We are also seeing increasing customer interest in developing CCS and geothermal projects.

  Enhancing our offering of technical, digital, and supply-chain integration services - Rig Direct® - and extending its global deployment

  We continue to enhance our Rig Direct® services offering and extend its deployment worldwide. For many years, we have provided these services-managing customer inventories and supplying pipes directly to their rigs on a just-in-time basis, complemented by technical advice and assistance on the material selection and field use in Mexico and Argentina. In response to changes in market conditions and customer's increased focus on reducing costs and improving the operational efficiency, we have expanded the scope and deployment of our Rig Direct® services across North America and other markets worldwide, including Colombia, North Sea, Romania and the United Arab Emirates, which now include digital solutions and more extensive supply-chain integration services. Through the supply of Rig Direct® services, we seek to integrate our operations with those of our customers, using digital technologies to shorten the supply chain and simplify operational and administrative processes, and providing technical services for well planning and well integrity to reduce costs, improve safety, and minimize environmental impact. They are also designed to

  differentiate us from our competitors and further strengthen our relationships with customers worldwide under long-term agreements.

  Securing inputs for our manufacturing operations

  We seek to secure our existing sources of raw material and energy inputs and to gain access to new sources of low-cost inputs which can help us maintain or reduce the cost of manufacturing our core products and reduce the carbon emissions intensity of our operations over the long term. We aim to achieve a vertically integrated value chain for our production. To this end, we purchase most of our supplies through Exiros, a specialized procurement company the ownership of which we share with Ternium. Exiros provides end-to-end procurement solutions, supplier sourcing, category-managed purchasing, suppliers' performance management, and inventory management.

  ‌Our Competitive Strengths

  We believe our main competitive strengths include:

• our global production, commercial, distribution and service capabilities, offering a full product range with flexible supply options backed up by local service capabilities in key oil and gas producing and industrial regions around the world;

• our ability to develop, design and manufacture technologically advanced products and provide integrated services;

• our solid and diversified customer base and long-standing relationships with major international oil and gas companies, together with strong and stable market shares in most of the countries in which we have manufacturing operations;

• our proximity to our customers;

• our highly talented management;

• our global workforce with diverse cultural backgrounds, knowledge and skills;

• our cost-competitive operations, primarily at state-of-the-art, strategically located production facilities with favorable access to raw materials, energy and labor, and a solid track-record of operating experience; and

• our strong financial condition.

‌Business Segments

Tenaris has one major business segment, "Tubes", which is also the reportable operating segment. All other business activities and operating segments that are not required to be separately reported, are disclosed within the "Others" segment.

The Tubes segment includes the production and sale of steel tubular products and related services mainly for the oil and gas industry, particularly OCTG used in drilling operations, line pipe used in transportation and processing activities and mechanical and structural tubes for other industrial applications, with production processes that consist in the production and transformation of steel into tubular products. Business activities included in this segment depend mainly on the global oil and gas industry, as major consumer of steel pipe products, particularly OCTG used in drilling activities. Demand for steel pipe products from the oil and gas industry has historically been volatile and depends primarily upon the number of oil and natural gas wells being drilled, completed and reworked, as well as the depth and drilling conditions of those wells. Major oil and gas companies have been adapting their strategies and some have allocated investments to renewable energies in response to the energy transition, while maintaining their capability to meet market demand for oil and gas and reducing the emissions from their operations. As the energy transition advances over the longer-term, demand for our products and services from low-carbon energy applications, such as geothermal, hydrogen, and CCS, is expected to increase, while demand for oil and gas applications may decrease.

Sales are generally made to end users, with exports being handled through a centrally managed global distribution network, while domestic sales are made through local subsidiaries.

The "Others" segment includes all business activities related to oilfield and hydraulic fracturing services, the production and sale of sucker rods, coiled tubing, tubes used for plumbing and construction applications and others as energy and raw materials that exceed internal requirements.

For more information on our business segments, see "II C. Accounting Policies - Segment information" to our audited consolidated financial statements included in this annual report.

‌Our Products

Our principal finished products are seamless and welded steel casing and tubing, line pipe, and various other mechanical and structural steel pipes for different uses. Casing and tubing are also known as OCTG. We manufacture our steel pipe products in a wide range of specifications, which vary in diameter, length, thickness, finishing, steel grades, coatings, threading and couplings. For more complex applications, including high pressure and high temperature applications, seamless steel pipes are usually specified and, for some standard applications, welded steel pipes can also be used. In addition to oil and gas applications, many of our products can also be used in low-carbon energy applications, such as geothermal, hydrogen, and CCS.

Casing. Steel casing is used to sustain the walls of oil and gas wells during and after drilling.

Tubing. Steel tubing is used to conduct crude oil and natural gas to the surface after drilling has been completed.

Line pipe. Steel line pipe is used to transport crude oil and natural gas from wells to refineries, storage tanks, and loading and distribution centers.

Mechanical and structural pipes. Mechanical and structural pipes are used by general industry for various applications, including the transportation of other forms of gases and liquids under high pressure.

Cold-drawn pipe. The cold-drawing process permits the production of pipes with the diameter and wall thickness required for use in boilers, superheaters, condensers, heat exchangers, automobile production, and several other industrial applications.

Premium joints and couplings. Premium joints and couplings are specially designed connections used to join lengths of steel casing and tubing for use in high temperature or high-pressure environments. A significant portion of our steel casing and tubing products are supplied with premium joints and couplings. We own an extensive range of premium connections and following the integration of the premium connections business of Hydril, we have marketed our premium connection products under the "TenarisHydril" brand name.

Pipe coatings. Concrete weight, anti-corrosion, thermal insulation, and flow assurance coatings for offshore and onshore pipelines.

Coiled tubing. Coiled tubing is used for oil and gas drilling and well workovers and for subsea pipelines.

Other products and services. We also manufacture sucker rods used in oil extraction activities, tubes used for plumbing and construction applications, provide oilfield and hydraulic fracturing services, and engage in other activities, such as the sale of energy and raw materials that exceed our internal requirements.

‌Production Process and Facilities

We operate relatively cost-competitive production facilities, which we believe is the result of:

• state-of-the-art, strategically located plants;

• favorable access to high quality raw materials, energy, and labor at competitive costs;

• operating history of more than 70 years, which translates into solid industrial know-how;

• constant benchmarking and best practices sharing across our facilities;

• increasing specialization of each of our facilities in specific product ranges; and

• extensive use of digital technologies in our production processes.

Our seamless pipe production and processing facilities are located in North and South America, Europe, and Asia. Our welded pipe production facilities are located in North and South America and in Saudi Arabia. We also produce steel bars in the United States, Mexico, Argentina, Italy, and Romania using the scrap-based electric arc furnace process that results in relatively low carbon emissions compared to primary steelmaking processes. In addition to pipe threading and finishing facilities at our integrated pipe production facilities, we have additional pipe and/or pipe accessory threading facilities that manufacture products in accordance with the American Petroleum Institute ("API") specifications, and we produce premium joints in Canada, China, Ecuador, Indonesia, Kazakhstan, Nigeria, Saudi Arabia, the United Arab Emirates, the United Kingdom, and the United States. We produce couplings in Argentina, China, Colombia, Indonesia, Mexico, and Romania, and pipe fittings in Mexico. We also have a global network of pipe coating plants in United States, Canada, Mexico, Norway, Indonesia, United Arab Emirates, Brazil, Argentina, Nigeria, Italy, Saudi Arabia, and Colombia.

In addition, we have sucker rods production facilities in Argentina, Brazil, Mexico, Romania, and the United States, and a coiled tubing production facility in the United States.

The following table shows our aggregate installed production capacity of seamless and welded steel pipes and steel bars at the dates indicated as well as the aggregate actual production volumes for the periods indicated.

At or for the year ended December 31,

Thousands of tons

Steel Bars

Effective Capacity (annual) (1)

Actual Production Tubes - Seamless

Effective Capacity (annual) (1)

Actual Production Tubes - Welded

Effective Capacity (annual) (1)

Actual Production

(1) Effective annual production capacity is calculated based on standard productivity of production lines, theoretical product mix allocations, the maximum number of possible working shifts and a continued flow of supplies to the production process.

In 2025, the capacity of seamless tubes increased due to efficiency increases in our Bay City seamless mill.