HHIP 3900-4702 5C Mount 4" 3-Jaw Lathe Chuck Outside Diameter Clamp Range is 0.079-3.150" Inside Diameter Jam Range is 1.181-3.543" Hole Through 5C Adapter is 0.75" Hole Through Chuck is 0.866" Quick set up in fixtures and 5C spindles. Chuck jaws are self centering, scroll type 5C adapter with standard internal and external threads 2 Sets of solid steel jaws, both internal and external. T.I.R. is 0.001"