Allen was a brand of hand tools, most widely recognized for its hexagon-shaped wrenches, known generically as "Allen wrenches". As a brand, it was last owned by Apex Tool Group.[1][2]
History
Allen created the Allen key in 1913 and created the Allen Manufacturing Company Inc advertisement for the Allen Safety Set Screw, a brand of set screw, in the Automobile Trade Directory, January 1913. Originally named Allen Manufacturing Company, the business produced hexagonal set screws and wrenches to fasten them. The terms "Allen wrench" (American English, though "Allen key" is also common in the US) and "Allen key" (British English)[3] are derived from the Allen brand name and refer to the generic product category "hex keys".
W.G. Allen[4]