I never see CRAFTSMAN C- series tools. I think this - C-20 1/2-inch square drive socket with a 5/8" service opening - is only the second piece I have ever found. Consequently, I haven't studied it. Alloy Artifacts attributes it to Snap-on. AA and Lauvin GJ/GG timeline seem to agree on 1932 to 1936. I can't find an attribution on the Tool Archives, but I remember Todd was diving into it pretty heavy last summer. I can't remember if he had an alternate OEM conclusion or the same. My other socket is chrome-plated as I recall. Oddly, this one looks cadmium-plated to me. See how gray and thin it is with the steel showing through on edges and elsewhere? I may be mistaken, but I don't recall CRAFTSMAN C- series being discussed here before.