Abstract: An adjustable workpiece-holding chuck including a chuck body with at least one jaw recess formed therein, which receive an operating jaw. A master jaw may be connected to the operating jaw via an adjustable cartridge assembly that includes a cartridge insert mounted to a recess formed in the master jaw. The cartridge insert includes a cartridge opening formed therein for receiving an adjustable screw. The adjustable screw is mounted to a yoke formed in the operating jaw, thereby releasably connecting the master jaw to the master jaw. The cartridge opening and the adjustable screw preferably have corresponding threads that form a full-diameter circumferential connection with each other. More preferably, the cartridge opening and the adjustable screw have complementary Acme threads.

Abstract: A rotatable chuck or work holder is provided with a pair of opposed jaws operated for simultaneous movement toward and away from each other and the centerline of rotation of the chuck to effect self-centering action of a workplace held between the chuck jaws. One of the chuck jaws has a rotatable and indexable work holding insert and the other having a rotatable work holding insert which cooperate to permit controlled rotation of a work piece held therebetween without releasing the grip on the work piece.