Insert, TCMT-21.52 Carbide

Finally getting consistent surface finishes on 303 stainless steel after switching to these inserts. The 0.25" IC fits my tool holder perfectly and the chip breaker clears chips without clogging.

I was a bit skeptical about the 7° relief angle, but it really helps with chip clearance on my aluminum parts. The single-sided chip breaker is working better than I expected for finish passes.

The 60° triangle geometry seats nicely in my tool holder, and that single-sided chip breaker clears swarf without clogging. I’ve run a few passes and the edge is holding up well, so this one’s earned its spot in the drawer.