I recently purchased a 4500 Sherline lathe with a bunch of accessories including the threading attachment. I already owned an American Watchtool Co. lathe with many collets. I was often pushing this lathe to its limits (sometimes even beyond) so I decided to upgrade my 12” watchmakers lathe to a 15” Sherline. I had planned on using my current collets with the Sherline but found out that it will only accept 8mm collets. Mine are 10mm. I was a bit disappointed. The 3 jaw chuck is fine but as we know, as with all 3 jaw scroll chucks, not very accurate. At least not for what we do. I didn’t want to dish out the money to purchase Sherline collets, I already dished out a lot for the lathe. I had to find a solution, and this is what I came up with. I turned this with a taper inside matching my collets and threaded it with my threading attachment. I can slip my 10mm collets in it then screw in the nut. I also made the nut and a tool bit to thread the inside. Once tightened, it holds the part very well. I know some of you will say: “But these collets are supposed to be pulled in by the threaded tail”. Yes, I agree, that’s how they’re supposed to work but here, I don’t think I had a choice. They are indeed pushed by the nut into the taper. It works. To assure repeatability, I marked the adapter to always remount it the same way. A little notch marked “A” to line up with jaw A. It spins within 1/2 a thousandth of an inch. And as for the colour, well, I tried to heat blue it, but I failed miserably. It was uneven and spotty. I did it in brass shavings but I don’t think it was very clean. It smoked pretty bad upon heating and a lot of it stuck to the parts. Something I’ll try again later. This time I’m going to get brass shavings from a Locksmith’s key cutting machine. It’ll be clean and even in chip size. M.