Original hardware trade vintage catalog for SHAKEPROOF LOCK WASHER COMPANY, was located at 2503 North Keeler Avenue, Chicago, IL. Distributors of shakeproof products. Lock Washers, Locking terminals, type 11 external tooth, 15 countersunk. Manufactured by Illinois Tool Works. Disbound from a large 1936 industrial hardware catalog, this unique old one page technical specifications brochure would display wonderfully matted and framed. A marvelous addition to your retro hardware library.