This propeller was manufactured by the Japanese Sumitomo Metals organization from a design of the German manufacturer VDM. From the markings, it was apparently for the World War II Aichi B7A Ryusei torpedo-dive bomber aircraft, Allied code name “Grace.”
The Propeller Division of Sumitomo Metal Industries was a primary manufacturer of World War II propellers for the Japanese military, the other being musical instrument manufacturer Nippon Gakki Company (the modern day Yamaha Corporation). Sumitomo began manufacturing propellers in 1925, and acquired a license for both the Hamilton Standard constant-speed counterweight propeller and VDM products in the late 1930s as Japan continued its military expansion into China.
Vereinigte Deutsche Metallwerke, or United German Metalworks, was a society of medium-sized firms formed in 1930. VDM’s member company, the Heddernheimer Metal Company, initiated the development of German metal propellers with a ground-adjustable propeller in the late 1920s.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.