I am a machine tool instructor and recieved some donated stainless that I am unsure what type it is. I am trying to cut a segmented thread. I tested my program in brass and it ran great. I switched the material to the stainless and I am having trouble with the threading insert holding up. It is a 3/8-16 thread. I started at 1000 RPM with a .002/side depth of cut. I slowed it down to 500 and it got worse. Do I need to go faster? What do you think?