vintage american industrial square-shaped c. 1930's-1940's american vintage industrial stamped aluminum specification plaque originally mounted against a thick cylindrical-shaped "lectromelt" steel refining or remelting tank housed at the a. finkl & sons foundry complex, located in chicago, il. the nicely aged and/pr patinated plaque was fabricated by or for the allis-chalmers mfg. co., pittsburgh, pa., and pittsburgh electromelt, mfg. co., pittsburgh, pa. the performance and other operation parameters were hand-punched with number dies. the industrial plaque features a unique lightning bolt graphic surrounding the "electromelt" trade name. only one available. three matching allis-chambers diamond-shaped plaques mounted above the specification plaques are available for purchase. measures 6 3/4 x 8 1/4 inches.