Abstract: Powder metal first pressed into a green briquette having an inner cavity is then sintered to form a rigid part. The inner cavity of the part is next sized in a lap-like operation by a spherical-shaped tool. The tool is rotated in an orbital pattern comprising a series of elliptically-shaped cycles. As the tool rotates, small successive portions of a surface of the cavity are contacted by the tool. This lap-like interaction between the tool and cavity surface not only sizes the cavity to an exact dimension but improves the wear quality of the cavity surface by increasing the density of a wall of the cavity as well as providing an improved surface finish.