This is an example of the heavier weight lunar hammers that were used during the Apollo 14, 15, 16, and 17 lunar missions. The heavy hammer was designed to chip samples off of large rocks and to drive core tubes into the lunar soil. When attached to an extension handle, the hammer was also used to dig surface furrows.
This particular hammer was used for training. It was sent by NASA for display to Japan in 1978. In 1979 ownership was transferred to the Smithsonian Institution.
This object is on display in Destination Moon at the National Air and Space Museum in Washington, DC.