An angled instrument assembly includes an angled sleeve, a driver shaft, and a tool bit. The angled sleeve includes a straight passage segment that meets an angled passage segment at a junction. The junction includes an inner elbow and an outer elbow. Material is removed from the inner surface of the inner elbow in order to improve the ease with which the driver shaft can be moved in and out of the angled sleeve. The assembly can also include drafted female or male engagement bodies for facilitating the engagement and disengagement of the tool bit with a tool bit engagement assembly located at the distal end of the driver shaft.