If you're asking about the ring on a P2-P3 shaft, I cut them at .060/.070".
PS - Predator spec may be a bit thinner, closer to .040/.050".
I tend to leave a little more meat where it matters, IMO.
You'll find that it's not just a simple ring.
It's what remains on the surface after the plug that it's attached to
is cut down to size. The cap of the plug starts-0ut 1/2" thick.
The stem is 1-1/4"long x 5/8" dia. It's threaded at the base of it's installed end.
I wouldn't install a single .060" thk ring on the end of a shaft and expect it to stay.