TENARIS S.A. HALF-YEAR REPORT 2016

TENARIS S.A. HALF-YEAR REPORT 2016

TABLE OF CONTENTS INTERIM MANAGEMENT REPORT... 2 COMPANY OVERVIEW...3 PRINCIPAL RISKS AND UNCERTAINTIES...4 BUSINESS OVERVIEW...6 RELATED PARTY TRANSACTIONS...12 MANAGEMENT CERTIFICATION...13 FINANCIAL INFORMATION...14 CONSOLIDATED CONDENSED INTERIM FINANCIAL STATEMENTS...14 INVESTOR INFORMATION...33

INTERIM MANAGEMENT REPORT CERTAIN DEFINED TERMS Unless otherwise specified or if the context so requires: References in this half-year report to the Company are exclusively to Tenaris S.A., a Luxembourg public limited liability company (société anonyme). References in this half-year report to Tenaris, we, us or our are to Tenaris S.A. and its consolidated subsidiaries. References in this half-year report to San Faustin are to San Faustin S.A., a Luxembourg public limited liability company (société anonyme) and the Company s controlling shareholder. Shares refers to ordinary shares, par value $1.00, of the Company. ADSs refers to the American Depositary Shares, which are evidenced by American Depositary Receipts, and represent two Shares each. OCTG refers to oil country tubular goods. tons refers to metric tons; one metric ton is equal to 1,000 kilograms, 2,204.62 pounds, or 1.102 U.S. (short) tons. billion refers to one thousand million, or 1,000,000,000. U.S. dollars, US$, USD or $ each refers to the United States dollar. PURPOSE This half-year report for the six-month period ended June 30, 2016 has been prepared in compliance with Article 4 of the Luxembourg Transparency Law of 11 January 2008, and should be read in conjunction with the annual report for the year ended December 31, 2015 (including the financial statements included therein) and the unaudited consolidated condensed interim financial statements included in this half-year report. PRESENTATION OF CERTAIN FINANCIAL AND OTHER INFORMATION Accounting Principles We prepare our consolidated financial statements in conformity with International Financial Reporting Standards as issued by the International Accounting Standards Board and adopted by the European Union, or IFRS. We publish consolidated financial statements expressed in U.S. dollars. The unaudited consolidated condensed interim financial statements included in this half-year report have been prepared in accordance with IAS 34, Interim Financial Reporting. These unaudited consolidated condensed interim financial statements should be read in conjunction with the audited consolidated financial statements for the year ended December 31, 2015, which have been prepared in accordance with IFRS. See Note 2 Accounting Policies and Basis of Presentation to our unaudited consolidated condensed interim financial statements included in this half-year report. The unaudited consolidated condensed interim financial statements included in this half-year report have been reviewed by PricewaterhouseCoopers Société coopérative, Cabinet de révision agréé, for purposes of complying with the requirements of the different jurisdictions where the Company is publicly listed. Rounding Certain monetary amounts, percentages and other figures included in this half-year 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. 2

Tenaris S.A. Half-year report 2016-Interim management report CAUTIONARY STATEMENT CONCERNING FORWARD-LOOKING STATEMENTS This half-year report and any other oral or written statements made by us to the public may contain forward-looking statements. Forward looking statements are based on management s current views and assumptions and involve known and unknown risks that could cause actual results, performance or events to differ materially from those expressed or implied by those statements. We use words 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 discussed under Principal Risks and Uncertainties, among them, the following: our ability to implement our business strategy or to grow through acquisitions, joint ventures and other investments; the competitive environment in our business and our industry; our ability to price our products and services in accordance with our strategy; 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; trends in the levels of investment in oil and gas exploration and drilling worldwide; and general macroeconomic and political 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 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 the forward-looking statements, which speak only as of the date of this half-year 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. COMPANY OVERVIEW We are a leading global manufacturer and supplier of steel pipe products and related services for the world s energy industry and for other industrial applications. Our customers include most of the world s leading oil and gas companies as well as engineering companies engaged in constructing oil and gas gathering, transportation, processing and power generation facilities. Our principal products include casing, tubing, line pipe, and mechanical and structural pipes. Over the last two decades, we have expanded our business globally through a series of strategic investments. We now operate an integrated worldwide network of steel pipe manufacturing, research, finishing and service facilities with industrial operations in the Americas, Europe, Asia and Africa and a direct presence in most major oil and gas markets. Our mission is to deliver value to our customers through product development, manufacturing excellence, and supply chain management. We seek to minimize risk for our customers and help them reduce costs, increase flexibility and improve time-to-market. Our employees around the world are committed to continuous improvement by sharing knowledge across a single global organization. For more information on the Company, including its competitive strengths, business segments and products see our annual report for the year ended December 31, 2015, and for a discussion and analysis of our financial condition and results of operations see Business overview - Operating and Financial Review and Prospects in this half-year report. 3

Tenaris S.A. Half-year report 2016-Interim management report PRINCIPAL RISKS AND UNCERTAINTIES We face certain risks associated to our business and the industry in which we operate. We are a global steel pipe manufacturer with a strong focus on manufacturing products and related services for the oil and gas industry. Demand for our products depends primarily on the level of exploration, development and production activities of oil and gas companies which is affected by current and expected future prices of oil and natural gas. Several factors, such as the supply and demand for oil and gas, and political and global economic conditions, affect, and may continue to affect, these prices. Oil and gas prices have reached levels which, in some areas, are close to or even below operating costs for the industry; accordingly, oil and gas companies may cut back further on their investment plans and consequently, absent a significant improvement in market conditions, demand for our products will decline further. Furthermore, fluctuations in industry inventory levels may adversely affect our sales and revenues. When oil and gas prices fall, as has been occurring over the last 24 months, oil and gas companies are generally expected to hold or reduce purchases of additional steel pipe products. Performance may be further affected by changes in governmental policies, the impact of credit restrictions on our customers ability to perform their payment obligations with us, and any adverse economic, political or social developments in our major markets. Furthermore, competition in the global market for steel pipe products may cause us to lose market share and hurt our sales and profitability. In addition, there is an increased risk that unfairly-traded steel pipe imports in markets in which Tenaris produces and sells its products may affect Tenaris s market share, deteriorate the pricing environment and hurt sales and profitability. Profitability may also be hurt if increases in the cost of raw materials, energy and other costs and limitations or disruptions to the supply of raw materials and energy, resulting in higher costs of production cannot be offset by higher selling prices or if the limited availability of such resources forces us to curtail production. Low levels of capacity utilization could also affect our results of operations and financial conditions. A recession in the developed countries, a cooling of emerging market economies or an extended period of below-trend growth in the economies that are major consumers of steel pipe products would likely result in reduced demand of our products, adversely affecting our revenues, profitability and financial condition. We have significant operations in various countries, including Argentina, Brazil, Canada, Colombia, Italy, Japan, Mexico, Nigeria, Romania and the United States, and we sell our products and services throughout the world. Therefore, like other companies with worldwide operations, our business and operations have been, and could in the future be, affected from time to time to varying degrees by political, economic and social developments and changes in, laws and regulations. These developments and changes may include, among others, nationalization, expropriations or forced divestiture of assets; restrictions on production, imports and exports, interruptions in the supply of essential energy inputs; restrictions on the exchange or transfer of currency, repatriation of capital, or payment of dividends or other contractual obligations; inflation; devaluation; war or other international conflicts; civil unrest and local security concerns, including high incidences of crime and violence involving drug trafficking organizations that threaten the safe operation of our facilities and operations; direct and indirect price controls; tax increases and changes in the interpretation, application or enforcement of tax laws and other retroactive tax claims or challenges; changes in laws, norms and regulations; cancellation of contract rights; and delays or denials of governmental approvals. As a global company, 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, which could adversely affect our financial position and results of operations. In addition, we may be subject to regulatory risks associated with our import and export activities. In May 2009, Venezuela nationalized the Company's majority-owned subsidiaries TAVSA - Tubos de Acero de Venezuela S.A. ( Tavsa ) and, Matesi Materiales Siderúrgicos S.A ( Matesi ), and Complejo Siderúrgico de Guayana, C.A ( Comsigua ), in which the Company has a non-controlling interest (collectively, the Venezuelan Companies ). On January 29, 2016, an arbitral award upheld Tenaris s claim that Venezuela had expropriated their investments in Matesi in violation of Venezuelan law as well as the bilateral investment treaties entered into by Venezuela with the Belgium-Luxembourg Economic Union and Portugal, granted compensation in the amount of $87.3 million for the breaches and ordered Venezuela to pay an additional amount of $85.5 million in pre-award interest, aggregating to a total award of $172.8 million, payable in full and net of any applicable Venezuelan tax, duty or charge. The tribunal granted Venezuela a grace period of six months from the date of the award to make payment in full of the amount due without incurring post-award interest, and resolved that if no, or no full, payment is made by then, post-award interest would apply at the rate of 9% per annum. Venezuela has 120 days from June 24, 2016 to seek the annulment of the award. However, we can give no assurance that the Venezuelan government will pay a fair and adequate compensation for our interest in Tavsa, Matesi and Comsigua, or that any such compensation will be freely convertible into or exchangeable for foreign currency. For further information on the nationalization of the Venezuelan subsidiaries, see note 30 Nationalization of Venezuelan Subsidiaries to our audited consolidated financial statements for the year ended December 31, 2015 and note 15 Nationalization of Venezuelan Subsidiaries to our unaudited consolidated condensed interim financial statements as of June 30, 2016 included in this half-year report. A key element of our business strategy is to develop and offer higher value-added products and services and to continuously identify and pursue growth-enhancing strategic opportunities. Even if we successfully implement our 4

Tenaris S.A. Half-year report 2016-Interim management report business strategy, it may not yield the expected results. We must necessarily base any assessment of potential acquisitions, joint ventures and investments, on assumptions with respect to operations, profitability and other matters that may subsequently prove to be incorrect. Failure to successfully implement our strategy, or to integrate future acquisitions and strategic investments, or to sell acquired assets or business unrelated to our business under favorable terms and conditions, could affect our ability to grow, our competitive position and our sales and profitability. 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. At June 30, 2016 we had $1,339 million in goodwill corresponding mainly to the acquisition of Hydril, in 2007 and Maverick, in 2006. In 2015, we recorded an impairment charge of $400 million on the goodwill of our welded pipe assets in the United States, reflecting the decline in oil prices, and their impact on drilling activity and the demand outlook for welded pipe products in the United States. Additionally, in 2015 we also recorded a $29 million impairment on the carrying value of our investment in Usiminas, which followed a prior $161 million impairment charge recorded after the conclusion of discussions with the SEC staff, that resulted in the Company revising the carrying value of its Usiminas investment and restating its financial statements to reduce the carrying amount of the Usiminas investment to $122 million as of September 30, 2014. If our management were to determine in the future that the goodwill or other assets were impaired, particularly as a consequence of deteriorating market conditions, we would be required to recognize a non-cash charge to reduce the value of these assets, which would adversely affect our results of operations. Potential environmental, product liability and other claims arising from the inherent risks associated with the products we sell and the services we render, including well failures, line pipe leaks, blowouts, bursts and fires, that could result in death, personal injury, property damage, environmental pollution or loss of production could create significant liabilities for us. Environmental laws and regulations may, in some cases, impose strict liability (even joint and several strict liability) rendering a person liable for damages to natural resources or threats to public health and safety without regard to negligence or fault. In addition, we are subject to a wide range of local, provincial and national laws, regulations, permit requirements and decrees relating to the protection of human health and the environment, including laws and regulations relating to hazardous materials and radioactive materials and environmental protection governing air emissions, water discharges and waste management. Laws and regulations protecting the environment have become increasingly complex and more stringent and expensive to implement in recent years. The cost of complying with such regulations is not always clearly known or determinable since some of these laws have not yet been promulgated or are under revision. These costs, along with unforeseen environmental liabilities, may increase our operating costs or negatively impact our financial condition and profitability. We conduct business in certain countries known to experience governmental corruption. Although we are committed to conducting business in a legal and ethical manner in compliance with local and international statutory requirements and standards applicable to our business, there is a risk that our employees or representatives may take actions that violate applicable laws and regulations that generally prohibit the making of improper payments to foreign government officials for the purpose of obtaining or keeping business, including laws relating to the 1997 OECD Convention on Combating Bribery of Foreign Public Officials in International Business Transactions such as the U.S. Foreign Corrupt Practices Act, or FCPA. As a holding company, our ability to pay cash dividends and make other payments to us depends on the results of operations and financial condition of our subsidiaries, which could be restricted by legal, contractual or other limitations, including exchange controls or transfer restrictions, and other agreements and commitments of our subsidiaries. The Company s controlling shareholder may be able to take actions that do not reflect the will or best interests of other shareholders. 5

Tenaris S.A. Half-year report 2016-Interim management report BUSINESS OVERVIEW Operating and Financial Review and Prospects The following discussion and analysis should be read in conjunction with the audited consolidated financial statements and the related notes included in our annual report for the year ended December 31, 2015, and is based on, and should be read in conjunction with, the unaudited consolidated condensed interim financial statements for the six-month period ended June 30, 2016, included in this half-year report. Certain information contained in this discussion and analysis and presented elsewhere in this half-year report, including information with respect to our plans and strategy for our business, includes forward-looking statements that involve risks and uncertainties. See Cautionary Statement Concerning Forward-Looking Statements in this half-year report. In evaluating this discussion and analysis, you should specifically consider the various risk factors identified in Principal Risks and Uncertainties, other risk factors identified elsewhere in this half-year report and other factors that could cause results to differ materially from those expressed in such forward-looking statements. Market Background and Outlook The oil market has moved closer to a balance between supply and demand. North American drilling activity, after falling to a new post-war low in the second quarter, seems to have bottomed out and some oil and gas operators are starting to add back rigs. In the rest of the world, drilling activity may also be close to reaching the bottom. The pace of any recovery, however, will be subdued while oil prices remain low and the financial position of the oil and gas industry and its suppliers continues to deteriorate. Our sales in the third quarter will continue to be affected by low levels of activity in North America and further price declines reflecting the intense competitive environment in the Eastern Hemisphere. In the fourth quarter, however, we should see a recovery in sales volumes and capacity utilization levels based on the current order backlog for our operations in the Middle East and Asia Pacific and a pick up in drilling activity in North America, accompanied by a gradual improvement in our EBITDA. 6

Tenaris S.A. Half-year report 2016-Interim management report Results of Operations Unaudited consolidated condensed interim income statement Six-month period (all amounts in thousands of U.S. dollars, unless otherwise stated) ended June 30, 2016 2015 Continuing operations % % Net sales 2,377,927 100.0 4,121,633 100.0 Cost of sales (1,742,240) (73.3) (2,765,069) (67.1) Gross profit 635,687 26.7 1,356,564 32.9 Selling, general and administrative expenses (628,563) (26.4) (873,727) (21.2) Other operating income (expense), net (4,774) (0.2) 7,658 0.2 Operating income 2,350 0.1 490,495 11.9 Finance income 44,107 1.9 23,085 0.6 Finance cost (9,118) (0.4) (15,620) (0.4) Other financial results (39,934) (1.7) (16,988) (0.4) (Loss) income before equity in earnings of non-consolidated companies and income tax (2,595) (0.1) 480,972 11.7 Equity in earnings of non-consolidated companies 30,339 1.3 12,184 0.3 Income before income tax 27,744 1.2 493,156 12.0 Income tax (8,971) (0.4) (166,890) (4.0) Income for the period 18,773 0.8 326,266 7.9 Attributable to: Owners of the parent 4,895 0.2 321,396 7.8 Non-controlling interests 13,878 0.6 4,870 0.1 18,773 0.8 326,266 7.9 7

Tenaris S.A. Half-year report 2016-Interim management report Selected consolidated financial position data Thousands of U.S. dollars (except number of shares) June 30, December 31, 2016 2015 Current assets... 5,115,446 5,743,031 Property, plant and equipment, net... 5,945,317 5,672,258 Other non-current assets... 3,308,918 3,471,685 Total assets... 14,369,681 14,886,974 Current liabilities... 1,752,032 1,754,775 Non-current borrowings... 32,859 223,221 Deferred tax liabilities... 661,377 750,325 Other non-current liabilities... 292,925 292,597 Total liabilities... 2,739,193 3,020,918 Capital and reserves attributable to the owners of the parent... 11,468,566 11,713,344 Non-controlling interests... 161,922 152,712 Equity... 11,630,488 11,866,056 Total liabilities and equity... 14,369,681 14,886,974 Number of shares outstanding... 1,180,536,830 1,180,536,830 8

Tenaris S.A. Half-year report 2016-Interim management report Six-month period ended June 30, 2016, compared to six-month period ended June 30, 2015 Summary Our sales in the first half of 2016 declined 42% compared to the first half of 2015, mainly due to a 32% decline in Tubes segment volumes and a 17% decline in average selling prices. EBITDA (i.e., operating income plus depreciation, amortization and impairment charges/ reversals) declined 58% to $329 million in the first half of 2016 compared to $792 million in the first half of the previous year, following the decline in sales and a reduction in the EBITDA margin, from 19.2% to 13.9%. EBITDA includes severance charges, due to the adjustment of the workforce to current market conditions, which amounted to $56 million in the first half of 2016 and $105 million in the first half of 2015. Net income attributable to owners of the parent during the first half of 2016 was $5 million or $0.01 per ADS, which compares with $321 million or $0.54 per ADS in the first half of 2015. The decline in net income mainly reflects a challenging operating environment affected by lower shipments and prices, a higher ratio of fixed costs resulting from low utilization of production capacity and severance costs to adjust the workforce to current market conditions. Cash flow from operations amounted to $689 million during the first half of 2016, including working capital reductions of $410 million. Following a dividend payment of $354 million in May 2016, and capital expenditures of $441 million during the first half of 2016, we reached a net cash position (i.e., cash, other current investments and fixed income investments held to maturity less total borrowings) of $1.8 billion at the end of June 2016. The following table shows our net sales by business segment for the periods indicated below: Millions of U.S. dollars For the six-month period ended June 30, Increase / 2016 2015 (Decrease) Tubes... 2,115 89% 3,759 91% (44%) Others... 263 11% 363 9% (28%) Total... 2,378 100% 4,122 100% (42%) Tubes The following table indicates for our Tubes business segment, sales volumes of seamless and welded pipes for the periods indicated below: Thousands of tons For the six-month period ended June 30, Increase / 2016 2015 (Decrease) Seamless... 761 1,149 (34%) Welded... 226 300 (25%) Total... 987 1,449 (32%) The following table indicates, for our Tubes business segment, net sales by geographic region, operating income and operating income as a percentage of net sales for the periods indicated below: Millions of U.S. dollars For the six-month period ended June 30, Increase / 2016 2015 (Decrease) Net sales - North America... 646 1,549 (58%) - South America... 595 954 (38%) - Europe... 295 425 (31%) - Middle East & Africa... 515 654 (21%) - Asia Pacific... 64 178 (64%) Total net sales... 2,115 3,759 (44%) Operating (loss) income 1... (44) 469 (109%) Operating income (% of sales)... (2.1%) 12.5% 1 Tubes operating income includes severance charges of $50 million in the first half of 2016 and $100 million in the first half of 2015. If these charges were not included operating income would have been $7 million in the first half of 2016 and $569 million in the first half of 2015. Net sales of tubular products and services decreased 44% to $2,115 million in the first half of 2016, compared to $3,759 million in the first half of 2015, as a result of a 32% decline in shipment volumes and a 17% decline in average selling prices. Sales were negatively affected by the adjustment in oil and gas drilling activity in response to the collapse in oil and gas prices and inventory adjustments taking place particularly in North America. In the first half of 2016, the average number of active drilling rigs, or rig count, declined 39% worldwide (56% in the United States and 9

Tenaris S.A. Half-year report 2016-Interim management report Canada and 19% in the rest of the world) compared to the average rig count in the first half of 2015. Operating results from tubular products and services decreased 109% to a loss of $44 million in the first half of 2016, from income of $469 million in the first half of 2015. Results have been negatively affected by the decline in sales and a reduction in operating margins affected by a higher ratio of fixed costs resulting from low utilization of production capacity and severance costs to adjust the workforce to current market conditions. Others The following table indicates, for our Others business segment, net sales, operating income and operating income as a percentage of net sales for the periods indicated below: Millions of U.S. dollars For the six-month period ended June 30, Increase / 2016 2015 (Decrease) Net sales... 263 363 (28%) Operating income... 46 22 115% Operating income (% of sales)... 17.6% 5.9% Net sales of other products and services decreased 28% to $263 million in the first half of 2016, compared to $363 million in the first half of 2015, mainly due to lower sales of sucker rods, coiled tubing and industrial equipment in Brazil, partially offset by higher sales of pipes for electric conduit in the United States. Operating income from other products and services increased 115%, to $46 million in the first half of 2016, compared to $22 million during the first half of 2015, following an improvement in the results of our electric conduit business in the United States. Selling, general and administrative expenses, or SG&A, amounted to $629 million in the first half of 2016 and $874 million in the first half of 2015, however, it increased as a percentage of net sales to 26.4% in the first half of 2016 compared to 21.2% in the first half of 2015 mainly due to the effect of fixed and semi fixed expenses on lower sales. Financial results amounted to a loss of $5 million in the first half of 2016, compared to a loss of $10 million in the first half of 2015. Net finance income amounted to a gain of $35 million in the first half of 2016, compared to a gain of $7 million in the first half of 2015. Other financial results amounted to a loss of $40 million in the first half of 2016, compared to a loss of $17 million in the first half of 2015. During the first half of 2016 other financial results were negatively affected by the Euro appreciation on Euro denominated intercompany liabilities, largely offset in currency translation adjustment and by the Brazilian Real appreciation on hedging instruments. Equity in earnings of non-consolidated companies generated a gain of $30 million in the first half of 2016, compared to a gain of $12 million in the first half of 2015. These results are mainly derived from our equity investment in our affiliate Ternium (NYSE:TX). Income tax charges amounted to $9 million in the first half of 2016, compared to $167 million in the first half of 2015. Income attributable to non-controlling interests amounted to $14 million in the first half of 2016, compared to $5 million in the first half of 2015. Results during the first half of 2016 are mainly attributable to our pipe coating subsidiary in Nigeria, while in the previous year they were mainly related to NKKTubes, our Japanese subsidiary. 10

Tenaris S.A. Half-year report 2016-Interim management report Liquidity and Capital Resources The following table provides certain information related to our cash generation and changes in our cash and cash equivalents position for the periods indicated below: Millions of U.S. dollars For the six-month period ended June 30, 2016 2015 Net cash provided by operating activities... 689 1,426 Net cash used in investing activities... (98) (1,225) Net cash used in financing activities... (491) (91) Increase (Decrease) in cash and cash equivalents... 100 110 Cash and cash equivalents at the beginning of year... 286 416 Effect of exchange rate changes... 6 (10) Increase (Decrease) in cash and cash equivalents... 100 110 Cash and cash equivalents at period end (net of overdrafts)... 393 517 At June 30, 2016 At June 30, 2015 Cash and cash equivalents at period end (net of overdrafts)... 393 517 Bank overdrafts... 2 3 Other current investments... 1,879 2,569 Fixed income investments held to maturity... 329 - Borrowings... (820) (1,261) Net cash... 1,783 1,828 Net cash provided by operations during the first half of 2016 amounted to $689 million (including working capital reductions of $410 million), compared to $1,426 million in the first half of 2015 (including working capital reductions of $912 million). In addition to the lower reduction in working capital the decline is mainly due to lower operating results. Capital expenditures amounted to $441 million in the first half of 2016, compared to $523 million in the first half of 2015, as we continue progressing in the construction of a greenfield seamless facility in Bay City, Texas. Following a dividend payment of $354 million in May 2016, our financial position at June 30, 2016, amounted to a net cash position (i.e., cash, other current investments and fixed income investments held to maturity less total borrowings) of $1.8 billion, similar to the level we had a year ago. OTHER SIGNIFICANT EVENTS OF THE PERIOD Annual General Meeting of Shareholders On May 4, 2016, the Company s annual general shareholders meeting approved all resolutions on its agenda. Among other resolutions adopted at the meeting, the shareholders approved the restated consolidated financial statements as of and for the year ended December 31, 2014, the consolidated financial statements as of and for the year ended December 31, 2015 and the annual accounts as at December 31, 2015, and acknowledged the related management and independent auditors' reports and certifications. The meeting also approved the payment of a dividend for the year ended December 31, 2015, of $0.45 per share (or $0.90 per ADS), or approximately $531 million, which includes the interim dividend of $0.15 per share (or $0.30 per ADS) paid in November 2015. Tenaris paid the balance of the annual dividend in the amount of $0.30 per share ($0.60 per ADS), or approximately $354 million, in May 2016. The annual general meeting approved the reduction in the number of the members of the board of directors to nine (9) and the re-election of Messrs. Roberto Bonatti, Carlos Condorelli, Roberto Monti, Gianfelice Mario Rocca, Paolo Rocca, Jaime Serra Puche, Alberto Valsecchi, Amadeo Vázquez y Vázquez and Guillermo Vogel, each to hold office until the meeting that will be convened to decide on the 2016 accounts. The board of directors subsequently confirmed and re-appointed Amadeo Vázquez y Vázquez, Jaime Serra Puche and Roberto Monti as members of Tenaris s audit committee, with Mr. Vázquez y Vázquez to continue as chairman. All three members of the audit committee qualify as independent directors under the articles and applicable law. 11

Tenaris S.A. Half-year report 2016-Interim management report The meeting appointed PricewaterhouseCoopers Société coopérative, Cabinet de révision agréé (member firm of PwC International Limited) as Tenaris s independent auditors for the fiscal year ending December 31, 2016. Usiminas' Capital Increase Usinas Siderúrgicas de Minas Gerais S.A., or Usiminas is a Brazilian producer of high quality flat steel products used in the energy, automotive and other industries and it is Tenaris s principal supplier of flat steel in Brazil for its pipes and industrial equipment businesses. On April 20, 2016, Tenaris s subsidiary Confab Industrial S.A., or Confab, subscribed, in the aggregate, to 1.3 million preferred shares for a total amount of BRL1.6 million (approximately $0.5 million). These preferred shares were issued on June 3, 2016. On April 18, 2016, Usiminas extraordinary general shareholders meeting approved an issuance of 200 million ordinary shares for an aggregate amount of BRL1 billion and Usiminas launched a multi-round subscription process for which, as of June 30, 2016, Tenaris had paid an aggregate amount of BRL57.5 million (approximately $16.6 million) into Usiminas. Accordingly, at June 30, 2016, Tenaris held 25.0 million ordinary shares and 1.3 million preferred shares of Usiminas and had paid the subscription price for shares not yet issued for a total amount of BRL57.5 million. On July 19, 2016, following the completion of the subscription process, Usiminas extraordinary general shareholders meeting homologated the capital increase, and Tenaris was issued, in the aggregate, 11.5 million ordinary shares for a total subscription price of BRL57.5 million (approximately $16.6 million). Following the issuance of these ordinary shares, Tenaris owns a total of 36.5 million ordinary shares and 1.3 million preferred shares, representing 3% of Usiminas capital, and the Ternium/Tenaris Group (comprising Ternium Investments, Siderar, Prosid and Confab), owns 39.6% of Usiminas ordinary shares and 1.8% of Usiminas preferred shares. For more information, see note 12 Investments in non-consolidated companies in our unaudited consolidated condensed interim financial statements as of June 30, 2016 included in this half-year report. RELATED PARTY TRANSACTIONS Tenaris is a party to several related party transactions, which include, among others, purchases and sales of goods (including steel pipes, flat steel products, steel bars, raw materials, gas and electricity) and services (including engineering services and related services) from or to entities controlled by San Faustin or in which San Faustin holds significant interests. Material related party transactions are subject to the review of the audit committee of the Company s board of directors and the requirements of the Company s articles of association and Luxembourg law. For further detail on Tenaris s related party transactions, see Note 13 Related party transactions to our unaudited consolidated condensed interim financial statements included in this half-year report. 12

Tenaris S.A. Half-year report 2016-Management certification MANAGEMENT CERTIFICATION We confirm, to the best of our knowledge, that: 1. the unaudited consolidated condensed interim financial statements prepared in conformity with International Financial Reporting Standards included in this half year report, give a true and fair view of the assets, liabilities, financial position and profit or loss of Tenaris S.A. and its consolidated subsidiaries, taken as a whole; and 2. the interim management report included in this half year report, includes a fair review of the important events that have occurred during the six-month period ended June 30, 2016, and their impact on the unaudited consolidated condensed interim financial statements for such period, material related party transactions and a description of the principal risks and uncertainties they face. /s/ Paolo Rocca Chief Executive Officer Paolo Rocca August 3, 2016 /s/ Edgardo Carlos Chief Financial Officer Edgardo Carlos August 3, 2016 13

Tenaris S.A. Half-year report 2016-Consolidated Condensed Interim Financial Statements FINANCIAL INFORMATION CONSOLIDATED CONDENSED INTERIM FINANCIAL STATEMENTS JUNE 30, 2016 14

Report of Independent Registered Public Accounting Firm To the Board of Directors of Tenaris S.A. We have reviewed the accompanying consolidated condensed interim statement of financial position of Tenaris S.A. and its subsidiaries as of 30 June 2016, and the related consolidated condensed interim statements of income and of comprehensive income for each of the three-month and six-month periods ended 30 June 2016 and 2015, and the consolidated condensed interim statements of changes in equity and of cash flows for the six-month periods ended 30 June 2016 and 2015. These consolidated condensed interim financial statements are the responsibility of the Company s management. We conducted our review in accordance with the standards of the Public Company Accounting Oversight Board (United States). A review of interim financial information consists principally of applying analytical procedures and making inquiries of persons responsible for financial and accounting matters. It is substantially less in scope than an audit conducted in accordance with the standards of the Public Company Accounting Oversight Board (United States), the objective of which is the expression of an opinion regarding the financial statements taken as a whole. Accordingly, we do not express such an opinion. Based on our review, we are not aware of any material modifications that should be made to the accompanying consolidated condensed interim financial statements for them to be in conformity with International Accounting Standard 34 Interim Financial Reporting as issued by the International Accounting Standards Board and adopted by the European Union. We previously audited in accordance with the standards of the Public Company Accounting Oversight Board (United States), the consolidated statement of financial position as of 31 December 2015, and the related consolidated statements of income, of comprehensive income, of changes in equity and of cash flows for the year then ended (not presented herein), and in our report dated 24 February 2016, we expressed an unqualified opinion on those consolidated financial statements. In our opinion, the information set forth in the accompanying consolidated condensed interim statement of financial position as of 31 December 2015, is fairly stated in all material respects in relation to the consolidated statement of financial position from which it has been derived. PricewaterhouseCoopers, Société coopérative Luxembourg, 3 August 2016 Represented by Fabrice Goffin 15 PricewaterhouseCoopers, Société coopérative, 400 Route d Esch, B.P. 1443, L-1014 Luxembourg T: +352 494848 1, F:+352 494848 2900, www.pwc.lu Cabinet de révision agréé. Expert-comptable (autorisation gouvernementale n 10028256) R.C.S. Luxembourg B 65 477 - TVA LU25482518

Tenaris S.A. Consolidated Condensed Interim Financial Statements for the six-month period ended June 30, 2016 CONSOLIDATED CONDENSED INTERIM INCOME STATEMENT (all amounts in thousands of U.S. dollars, unless otherwise stated) Three-month period ended June 30, Six-month period ended June 30, Notes 2016 2015 2016 2015 Continuing operations (Unaudited) (Unaudited) Net sales 3 1,120,673 1,868,078 2,377,927 4,121,633 Cost of sales 4 (814,847) (1,324,377) (1,742,240) (2,765,069) Gross profit 305,826 543,701 635,687 1,356,564 Selling, general and administrative expenses 5 (341,996) (437,620) (628,563) (873,727) Other operating income (expense), net (3,644) 5,041 (4,774) 7,658 Operating (loss) income (39,814) 111,122 2,350 490,495 Finance Income 6 24,212 10,978 44,107 23,085 Finance Cost 6 (4,814) (9,363) (9,118) (15,620) Other financial results 6 (9,776) (9,718) (39,934) (16,988) (Loss) income before equity in earnings of nonconsolidated companies and income tax (30,192) 103,019 (2,595) 480,972 Equity in earnings of non-consolidated companies 18,612 4,269 30,339 12,184 (Loss) income before income tax (11,580) 107,288 27,744 493,156 Income tax 2,403 (34,965) (8,971) (166,890) (Loss) income for the period (9,177) 72,323 18,773 326,266 Attributable to: Owners of the parent (13,266) 66,314 4,895 321,396 Non-controlling interests 4,089 6,009 13,878 4,870 (9,177) 72,323 18,773 326,266 Earnings per share attributable to the owners of the parent during the period: Weighted average number of ordinary shares (thousands) 1,180,537 1,180,537 1,180,537 1,180,537 Continuing operations Basic and diluted (loss) earnings per share (U.S. dollars per share) (0.01) 0.06-0.27 Basic and diluted (loss) earnings per ADS (U.S. dollars per ADS) (1) (0.02) 0.11 0.01 0.54 (1) Each ADS equals two shares. CONSOLIDATED CONDENSED INTERIM STATEMENT OF COMPREHENSIVE INCOME (all amounts in thousands of U.S. dollars) Three-month period ended June 30, Six-month period ended June 30, 2016 2015 2016 2015 (Unaudited) (Unaudited) (Loss) income for the period (9,177) 72,323 18,773 326,266 Items that will not be reclassified to profit or loss: Remeasurements of post employment benefit obligations 1,433 (1,373) 1,433 (1,373) Income tax on items that will not be reclassified (763) 292 (763) 292 670 (1,081) 670 (1,081) Items that may be subsequently reclassified to profit or loss: Currency translation adjustment 11,769 49,861 102,463 (131,340) Change in value of available for sale financial instruments and cash flow hedges 450 5,161 (5,734) 5,549 Share of other comprehensive income of non-consolidated companies: - Currency translation adjustment 14,652 879 8,005 (34,888) - Changes in the fair value of derivatives held as cash flow hedges and others (394) (2,943) (796) (3,696) Income tax relating to components of other comprehensive income - 204 - (107) Other comprehensive income (loss) for the period, net of tax 27,147 52,081 104,608 (165,563) Total comprehensive income for the period 17,970 124,404 123,381 160,703 Attributable to: Owners of the parent 14,032 118,258 109,388 155,940 Non-controlling interests 3,938 6,146 13,993 4,763 17,970 124,404 123,381 160,703 The accompanying notes are an integral part of these Consolidated Condensed Interim Financial Statements. These Consolidated Condensed Interim Financial Statements should be read in conjunction with our audited Consolidated Financial Statements and notes for the fiscal year ended December 31, 2015. 16

Tenaris S.A. Consolidated Condensed Interim Financial Statements for the six-month period ended June 30, 2016 CONSOLIDATED CONDENSED INTERIM STATEMENT OF FINANCIAL POSITION (all amounts in thousands of U.S. dollars) At June 30, 2016 At December 31, 2015 Notes (Unaudited) ASSETS Non-current assets Property, plant and equipment, net 8 5,945,317 5,672,258 Intangible assets, net 9 2,032,412 2,143,452 Investments in non-consolidated companies 12 524,625 490,645 Available for sale assets 21,572 21,572 Other investments 10 330,856 394,746 Deferred tax assets 197,906 200,706 Receivables 201,547 9,254,235 220,564 9,143,943 Current assets Inventories 1,533,666 1,843,467 Receivables and prepayments 126,817 148,846 Current tax assets 162,188 188,180 Trade receivables 1,019,342 1,135,129 Other investments 10 1,879,082 2,140,862 Cash and cash equivalents 10 394,351 5,115,446 286,547 5,743,031 Total assets 14,369,681 14,886,974 EQUITY Capital and reserves attributable to owners of the parent 11,468,566 11,713,344 Non-controlling interests 161,922 152,712 Total equity 11,630,488 11,866,056 LIABILITIES Non-current liabilities Borrowings 32,859 223,221 Deferred tax liabilities 661,377 750,325 Other liabilities 228,634 231,176 Provisions 64,291 987,161 61,421 1,266,143 Current liabilities Borrowings 787,187 748,295 Current tax liabilities 124,813 136,018 Other liabilities 250,208 222,842 Provisions 14,296 8,995 Customer advances 68,939 134,780 Trade payables 506,589 1,752,032 503,845 1,754,775 Total liabilities 2,739,193 3,020,918 Total equity and liabilities 14,369,681 14,886,974 The accompanying notes are an integral part of these Consolidated Condensed Interim Financial Statements. These Consolidated Condensed Interim Financial Statements should be read in conjunction with our audited Consolidated Financial Statements and notes for the fiscal year ended December 31, 2015. 17

Tenaris S.A. Consolidated Condensed Interim Financial Statements for the six-month period ended June 30, 2016 CONSOLIDATED CONDENSED INTERIM STATEMENT OF CHANGES IN EQUITY (all amounts in thousands of U.S. dollars) Share Capital (1) Legal Reserves Attributable to owners of the parent Currency Share Translation Other Premium Adjustment Reserves (2) Retained Earnings (3) Noncontrolling interests Total Total (Unaudited) Balance at December 31, 2015 1,180,537 118,054 609,733 (1,006,767) (298,682) 11,110,469 11,713,344 152,712 11,866,056 Income for the period - - - - - 4,895 4,895 13,878 18,773 Currency translation adjustment - - - 102,348 - - 102,348 115 102,463 Remeasurements of post employment benefit obligations, net of taxes - - - - 670-670 - 670 Change in value of available for sale financial instruments and cash flow hedges, net of taxes - - - - (5,734) - (5,734) - (5,734) Share of other comprehensive income of non-consolidated companies - - - 8,005 (796) - 7,209-7,209 Other comprehensive income (loss) for the period - - - 110,353 (5,860) - 104,493 115 104,608 Total comprehensive income (loss) for the period - - - 110,353 (5,860) 4,895 109,388 13,993 123,381 Acquisition of non-controlling interests - - - - (5) - (5) (472) (477) Dividends paid in cash - - - - - (354,161) (354,161) (4,311) (358,472) Balance at June 30, 2016 1,180,537 118,054 609,733 (896,414) (304,547) 10,761,203 11,468,566 161,922 11,630,488 Share Capital (1) Legal Reserves Attributable to owners of the parent Currency Share Translation Other Premium Adjustment Reserves (2) Retained Earnings (3) Noncontrolling interests Total Total (Unaudited) Balance at December 31, 2014 1,180,537 118,054 609,733 (658,284) (317,799) 11,721,873 12,654,114 152,200 12,806,314 Income for the period - - - - - 321,396 321,396 4,870 326,266 Currency translation adjustment - - - (130,816) - - (130,816) (524) (131,340) Remeasurements of post employment benefit obligations, net of taxes - - - - (1,081) - (1,081) - (1,081) Change in value of available for sale financial instruments and cash flow hedges, net of taxes - - - - 5,025-5,025 417 5,442 Share of other comprehensive income of non-consolidated companies - - - (34,888) (3,696) - (38,584) - (38,584) Other comprehensive (loss) income for the period - - - (165,704) 248 - (165,456) (107) (165,563) Total comprehensive (loss) income for the period - - - (165,704) 248 321,396 155,940 4,763 160,703 Acquisition of non-controlling interests - - - - 659-659 (1,513) (854) Dividends paid in cash - - - - - (354,161) (354,161) - (354,161) Balance at June 30, 2015 1,180,537 118,054 609,733 (823,988) (316,892) 11,689,108 12,456,552 155,450 12,612,002 (1) The Company has an authorized share capital of a single class of 2.5 billion shares having a nominal value of USD1.00 per share. As of June 30, 2016 and 2015 there were 1,180,536,830 shares issued. All issued shares are fully paid. (2) Other reserves include mainly the result of transactions with non-controlling interest that do not result in a loss of control, the remeasurement of post-employment benefit obligations and the changes in value of cash flow hedges and in available for sale financial instruments. (3) The Distributable Reserve and Retained Earnings as of June 30, 2016 calculated in accordance with Luxembourg Law are disclosed in Note 11. The accompanying notes are an integral part of these Consolidated Condensed Interim Financial Statements. These Consolidated Condensed Interim Financial Statements should be read in conjunction with our audited Consolidated Financial Statements and notes for the fiscal year ended December 31, 2015. 18