Abstract: Adzer bit assemblies (18) are of noncircular outer surface configuration and have a noncircular surface seated against a face (15) of similar noncircular shape to hold the assembly against rotation. When becoming worn, the adzing bit assembly can be loosened from the adzing head (99), and rotated to present a fresh cutting surface.

Abstract: The adzing bit assembly includes a circular cutting bit with a circular edge formed by the merging of its flat face and its peripheral surface at an acute angle. A cutting bit shield abuts and covers the face of the cutting bit and extends to a diameter substantially equal to the diameter of the cutting edge, so as to shield the face and the cutting edge of the cutting bit. The cutting bit is fabricated from harder material than the cutting bit shield, so that the cutting bit shield wears away during use and the circular cutting edge of the cutting bit is progressively exposed.