Went thru a 5" tailstock chuck that came with my Niles lathe. I think It is original equipment for the machine, which makes it at least 124 years old. interesting construction, and the tolerances are very impressive, even by today's standards. The only markings I could find othe than the jaw, body, and gear location numbers was a stamped 326. Probably weighs twice what my Chinese 5" weighs. Will need to regrind the jaw ends, as someone looks like the took an angle grinder to them. Other than that it's in nice condition. Also made a quick and dirty chuck wrench, as I laid down the one I had, and the shop gremlins carried it off somewhere. Mike