View Full Version : What Material for Lathe Collet chuck?

12-25-2009, 01:47 PM
I know this has been discussed, but I couldn't find anything when I searched. I am going to make an ER 40 collet chuck that will be a direct mount on my lathes L00 spindle nose. This will be for occasional use in the home shop. The material will need to start out as a 3.75-4" diameter about four inches long. I don't have the facilities or the money to have it heat treated. My thought was that 4140 annealed would probably be the best from a wear, machinability, and avialability perspective. 4140HT seems the best from a toughness aspect, but how is it to machine? Cast iron would be cheaper, but doesn't seem hard enough. What say you?

Gary Gill
12-25-2009, 02:27 PM
I made my ER40 collet chuck using 12L14 for the ease of machining on my 7 x 12 lathe. I am careful when handling the chuck.

j king
12-25-2009, 02:54 PM
I would recommend 4140 ht. It machines fine.

12-25-2009, 04:28 PM
We use 4140HT at work a lot it is tuff but machines good. I think it would be a good choice and it's a lower cost tool steel compared to A-2 S-7 etc.

12-25-2009, 04:35 PM
I've made a bunch of collet adapters from CRS and 12L14 for a variety of collets. The one I use in my own shop shows no discernable wear after several years, and if it did I can always take a skim cut. I think for non-production shop use the 4140 will serve just fine.