A tool assembly for attachment to a cutter wheel for use in tree stump removal is described. The assembly includes a tooth and a pocket. The tooth includes a cutting head and a shank depending from the head. The shank includes a first flat opposite a second flat. The pocket defines opposing wheel and exterior faces. A tooth receiving slot is formed in the wheel face and includes a base. In this regard, the tooth shank defines one of a projection and a recess and the pocket defines the other of the projection and the recess. Upon coupling the tooth shank to the tooth receiving slot, substantially an entirety of a peripheral edge of the projection contacts a wall of the recess to resist a torque applied to the cutting head.