Thanks all - yes the blanket statement of stainless being "hard" is plain wrong, if you want a quick description of some of the more commonly available alloys - their strengths, machineabillity etc look at speedy metals (they sell in small quantities). Hit a brake pad backing or a brake pin with a file and you will score both of them.

I asked because I have the equipment to make my own and was wondering if there was an actual reason that I may not be aware of. I figure I'll make some to try out. Now to get a new one so I can get an accurate measurement (99% that the OD is a even metric size) 303 stainless machines really easily (no work hardening problems and is resistant to galling).

Paul