I just bought a craftsman 12 x 48 lathe and strangely it came with two 3 jaw chucks. I had assumed it had a 3 and a 4 jaw, so now I'm looking to get rid of one of the 3 jaws in exchange for a 4 jaw. I just cleaned it up and it seems to be in fine shape. 1 1/2 x 8tpi and I would like the same threads on the 4 jaw.