Grind a face trepanning tool for the lathe

We hand grind and demonstrate a high speed steel face trepanning tool for the lathe. This particular geometry tool leaves a center core of material that can be used for another part. Trepanning is an energy efficient type of hole cutting that removes an annulus (ring shaped) of material without converting the entire center into chips like a drill. This geometry can also be used for face groove oring seals.