Abstract: A honing assembly comprising a hollow head or shell provided with a plurality of circumferentially spaced slots, honing elements projecting from said slots, and an adjusting member longitudinally adjustably supported within the head. The adjusting member has longitudinally tapered surfaces provided with elongated undercut grooves. The honing elements have studs shaped to fit the grooves so that longitudinal movement of the adjusting member will cause radially inward or outward movement of the honing elements depending on the direction of movement of the adjusting member.