View Full Version : Need help identifying material in collet closer

08-17-2009, 12:00 PM
Hi all,

The other day I scored an old Hardinge collet closer. I need to make a 9" extension to the tube in order for it to work on my lathe. I cut the tube last night, measured it and found that it was 1.4030" OD, 1.0910" ID. The wall thickness is .1560"

I faced and chamfered the ends for welding then realizing that I did not know what the material was. About all I know is it machines well. I looked on the Hardinge web sight, couldn't find this closer (it's pretty old) and couldn't find any specs on the materials they use.

Since I want to weld in an extension, I would like to match materials if possible.

Does anybody know what steel these were made of? I am thinking it is DOM tubing.

Thanks for your help,


08-17-2009, 12:31 PM
How about just cutting some overlaps on both pieces, then silver brazing the two together.
That would eliminate the issue of what steel it is, and certainly in my case, make for a more aesthetically appealing seam too.
Just a thought.

p.s. ...would also eliminate or minimize the welding flash on the inside.

08-17-2009, 12:35 PM
Being thin wall, probably a 1026 DOM. But being old like it is, it probably has very high Sufur and Phorphurs content, may not weld very good. I would just make it a box x pin extension and loctite it to the existing collet closure to get the correct length needed. This would assure absolute concentricity with near zero runout.