Cutting a 3/16 keyway in 3/4" CR shaft steel using an end mill. I keep breaking end mills.
It was recommended in - Machine Shop Trade Secrets to make a hexagonal single flute end mill for this.
McMaster has M2 HHS 3/16 drill rod. Could I cut a piece and grind a 1/2 way through flat and use that instead of the whole hexagonal shape.