EX-21 4 0004.txt 2 Subsidiaries The following is a list of the subsidiaries of Gibraltar Steel Corporation. The names of indirectly owned subsidiaries are indented under the names of their respective parent corporations: Gibraltar Steel Corporation of New York New York Wm. R. Hubbell Steel Corporation Illinois Carolina Commercial Heat Treating, Inc. Nevada Southeastern Metals Manufacturing Company, Inc. Florida Solar Group, Inc. Delaware Appleton Supply Co., Inc. Delaware United Steel Products Company Minnesota Harbor Metal Treating Co. Michigan Harbor Metal Treating of Indiana, Inc. Michigan K & W Metal Fabricators, Inc. Colorado Hi-Temp Heat Treating, Inc. Delaware Brazing Concepts Company Michigan Milcor, Inc. Delaware Gibraltar Steel Corporation Flight Services Corp. New York Gibraltar Strip Steel, Inc. Delaware Integrated Technologies International, Ltd. Delaware Cleveland Pickling, Inc. Delaware GIT Limited New York 55