EX-8.1 4 exh_81.htm EXHIBIT 8.1

Exhibit 8.1

Tenaris – List of subsidiaries of Tenaris S.A.

Significant operating subsidiaries

We conduct all our operations through subsidiaries. The following table shows the significant operating subsidiaries of the Company and its direct and indirect ownership in each subsidiary as of December 31, 2017, 2016 and 2015.

|  | Country of |  |  | Percentage of ownership
Company |  | Organization |  | Main activity | 2017 | 2016 | 2015
ALGOMA TUBES INC. |  | Canada |  | Manufacturing of seamless steel pipes | 100% | 100% | 100%
CONFAB INDUSTRIAL S.A. |  | Brazil |  | Manufacturing of welded steel pipes and capital goods | 100% | 100% | 100%
DALMINE S.p.A. |  | Italy |  | Manufacturing of seamless steel pipes | 100% | 100% | 99%
EXIROS B.V. |  | Netherlands |  | Procurement of raw materials and other products or services | 50% | 50% | 50%
HYDRIL COMPANY |  | USA |  | Manufacture and marketing of premium connections | 100% | 100% | 100%
MAVERICK TUBE CORPORATION |  | USA |  | Manufacturing of welded steel pipes | 100% | 100% | 100%
METALMECANICA S.A. |  | Argentina |  | Manufacturing of sucker rods | 100% | 100% | 100%
NKKTUBES |  | Japan |  | Manufacturing of seamless steel pipes | 51% | 51% | 51%
P.T. SEAMLESS PIPE INDONESIA JAYA |  | Indonesia |  | Manufacturing of seamless steel products | 89% | 77% | 77%
PRUDENTIAL STEEL LTD. |  | Canada |  | Manufacturing of welded steel pipes | 100% | 100% | 100%
S.C. SILCOTUB S.A. |  | Romania |  | Manufacturing of seamless steel pipes | 100% | 100% | 100%
SIAT SOCIEDAD ANONIMA |  | Argentina |  | Manufacturing of welded and seamless steel pipes | 100% | 100% | 100%
SIDERCA S.A.I.C. |  | Argentina |  | Manufacturing of seamless steel pipes | 100% | 100% | 100%
TENARIS BAY CITY, INC. |  | USA |  | Manufacturing of seamless steel pipes | 100% | 100% | 100%
TENARIS COILED TUBES LLC |  | USA |  | Manufacturing of coiled tubing | 100% | 100% | 100%
TENARIS CONNECTIONS B.V. |  | Netherlands |  | Development, management and licensing of intellectual property | 100% | 100% | 100%
TENARIS FINANCIAL SERVICES S.A. |  | Uruguay |  | Financial company | 100% | 100% | 100%
TENARIS GLOBAL SERVICES S.A. |  | Uruguay |  | Holding company and marketing of steel products | 100% | 100% | 100%
TENARIS TUBOCARIBE LTDA. |  | Colombia |  | Manufacturing of welded and seamless steel pipes | 100% | 100% | 100%
TUBOS DE ACERO DE MEXICO S.A. |  | Mexico |  | Manufacturing of seamless steel pipes | 100% | 100% | 100%