Why is it called that? Is a hammer used to strike it?
Are both ends a welded-on socket?
I think the sockets were pressed on and possibly welded down in the center of the socket. Not sure if they were meant to be hammered with or named for the shape. Honestly I didn’t know hammer head was the actual name Snap On called them but it certainly is.
After some research in the Collecting Snap On catalogs, I think they were first marketed in 1927.
-1927, part of the Ferret 3/8 socket set, which included just two wrenches 7/16x 1/2 and 9/16x 5/8.
-1928-1931, now three wrenches listed. 7/16x1/2, 9/16x5/8, 11/16x3/4.
- 1932-1938, only one wrench available. 9/16 x 5/8.
That’s what I found with the catalogs available on the site. What a great resource as always.