Abstract: A generally horizontal wood comminuter has a crosswise rotor with comminuting knives moving in a path of rotation and a crosswise coacting anvil. A feed works provides a material support surface and a power-driven feed member above it for feeding material toward the rotor. The rotor is driven in an uphill path of rotation relative to the feed works. Lift arms pivotally carry the feed member for swinging vertical movement toward and away from the material support surface. A crosswise deflector plate is carried independently of the lift arms and extends toward the anvil and a crosswise lift arm plate coacts with the deflector plate to contain fragmented material. The anvil and a grate retainer preferably are pivotal to move together from an operative to an inoperative position. A torque limiting device controls the drive of the rotor.