Originally Posted by
warrenb
You sure about those dimensions? a 1.25" deep slot in a 1.25" diameter rod? Or are you coming in from the end?
If coming in from the end you're going to have a problem of the shank being slightly larger than the cutting edges. If it were me....
I would rough and finish with a 3/16" carbide. Working within the tolerances cut you max depth at .001 extra. Then next deepest .000 on part line. Then final depths brought in ,001 per step. If you try cutting with a 1/4 endmill you're going to have a really bad surface and once you're past the cutting edge you'll rub on the shank.