Abstract: A bit includes a body, a cutting edge, and a shim. The body has a shank end and a cutting end, and the shank end is arranged to be held by a drill or router. The cutting edge is positioned at the cutting end of the body. The shim is between the cutting end of the body and the cutting edge, and the shim is arranged to absorb forces so as to protect the cutting edge.

Abstract: A tool has a shaft and a tip on the shaft. The tip supports rougher and chipbreaker finisher wings which, for example, may be polycrystalline diamond wings. Also, the rougher and chipbreaker finisher wings may be arranged, for example, to provide either upshear or downshear forces. As another example, both upshear and downshear rougher and chipbreaker finisher wings may be arranged to produce corresponding upshear and downshear forces.