1 EXHIBIT 21 WORTHINGTON INDUSTRIES, INC. A DELAWARE CORPORATION JURISDICTION OF SUBSIDIARY (1) INCORPORATION - ------------------------------------------------------------------------------------------- Dietrich Industries, Inc. Pennsylvania The Gerstenslager Company Michigan I. H. Schlezinger, Inc. Ohio Worthington Industries of Michigan, Inc. Michigan SUBSIDIARIES OF WORTHINGTON INDUSTRIES OF MICHIGAN, INC. The Worthington Steel Company Indiana The Worthington Steel Company Kentucky The Worthington Steel Company Maryland The Worthington Steel Company North Carolina The Worthington Steel Company Delaware .......NRM Trucking Co. (2) Delaware Worthington Steel of Michigan, Inc. Michigan d/b/a The Worthington Steel Company Worthington Cylinder Corporation Ohio Worthington Acetylene Cylinders, Inc. (3) Alabama (d/b/a North American Cylinders, Inc.) Worthington Cylinders of Canada, Inc. (3) Ontario, Canada Steel Cylinder Manufacturing, Inc. (4) Ontario, Canada Buckeye Steel Castings Company Ohio Buckeye Energy Company, Inc. (5) Ohio B-I Sales, Inc. (5) Michigan GSI Engineering, Inc. (5) Delaware Buckeye International Development, Inc.(5) Ohio Worthington Custom Plastics, Inc. (5) Ohio Worthington Precision Metals, Inc. (6) Tennessee Industrias Worthington Do Brasil Ltda Laws / Federative Republic of Brazil Worthington Industries of Mexico, S.A. de C.V. Mexico (1) All subsidiaries are 100% owned by the listed parent unless otherwise noted Some minor or non-functioning corporations are not listed (2) Wholly-owned subsidiary of Worthington Steel Company(DE) (3) Wholly-owned subsidiary of Worthington Cylinder Corporation (4) Wholly-owned subsidiary of Worthington Cylinders of Canada, Inc. (5) Wholly-owned subsidiary of Buckeye Steel Castings Company (6) Wholly-owned subsidiary of Worthington Custom Plastics, Inc. 2 JOINT VENTURES Worthington Specialty Processing (7) Michigan London Industries, Inc. (8) Ohio TWB Company, L.L.C. (9) Michigan Worthington Armstrong Venture (10) Delaware Acerex, S.A. de C.V. (11) Mexico Worthington S.A. (12) Brazil * * * * * (7) 50% Joint Venture w/USX Corporation - owned by Worthington Steel of Michigan, Inc. (8) 60% owned Joint Venture with Nissen, Sumitomo & Sumitomo Corp. of America -owned by Worthington Custom Plastics, Inc. (9) 33% Joint Venture - Owned by Worthington Steel of Michigan, Inc. (10) 50% Joint Venture w/Armstrong Ventures, Inc. - Owned by The Worthington Steel Company (DE) (11) 50% Joint Venture with Hylsa S.A. de C.V. Owned by Worthington Industries Mexico, S.A. de C.V. (12) 52% Joint Venture - Owned by Worthington, S.A. 2