Alloy Artifacts
Williams
Round-Shank Box-End Wrenches
Williams introduced 12-point box-end wrenches some years after the first "Superrench" wrenches were offered. Although the exact date is not known, box-end wrenches were definitely available by 1931, based on an A-373 catalog update from that time. These first generation box wrenches featured round shanks and were marked "Duohex-Box", with "Duohex" signifying the double-hex (12-point) broaching.
The early 12-point wrenches were also marked with a notation for patent #1,424,069, issued in 1922 to F. Blackmar. This patent describes the design of a 12-point box wrench with an offset handle, and appears to have a bit of a curious history. There's no patent assignment listed with the initial patent document, but Snap-On seems to have acquired it at a later date, possibly around 1930. In the early 1930s Snap-On marked some 12-point wrenches with the patent number, and a few other companies did so as well. (Snap-On also marked some 12-point sockets with the patent.)
The Williams catalogs for 1931 and 1933 acknowledge licensing the Blackmar patent, but by 1937 were no longer mentioning it in the catalogs. Thus the presence of the patent marking on a wrench indicates a likely production date in the early 1930s.