Thomas Hamilton, general manager of the aircraft department of Matthews Brothers Manufacturing Company, of Milwaukee, Wisconsin, primarily a producer of furniture, bought the propeller business from Matthews in 1919 and formed the Hamilton Aero Manufacturing Company, later becoming a secondary source to the United States government for the ground-adjustable propeller pioneered by Standard Steel.
William E. Boeing, one of the founders of the United Aircraft and Transport Corporation, enticed Hamilton to join UATC. With the later acquisition of Standard Steel, the Hamilton Standard Propeller Corp. was formed.
The hydromatic propeller introduced in the 1930s was a significant advance over the counterweight, controllable pitch propeller. The application of oil pressure to both sides of the actuating piston provided increased capacity and the capability of feathering or unfeathering by a single control knob. Reverse pitch permitted shortened landing roll.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.