Lathe Chuck Adapter Back Plates; Nominal Chuck Size: 6 in; Mount Type: Threaded Mount: 2-1/4 - 8; Spindle Nose Type: Threaded; Chuck Compatibility: 1-101-0600,1-103-0600,1-151-0600,1-153-0600,; Through-hole Diameter: 2.25 in; Chuck Diameter Compatibility