Jacobs 6289C 33BA Medium Duty Plain Bearing Keyed Chuck 2.0 to 13.0 Millimeter Capacity with 5/8-Inch 16 Threaded Mount High accuracy T.I.R. 0.004-Inch maximum at half capacity Jaws center-ground for absolute straightness and alignment One-piece sleeve eliminates crack between driving teeth often found in other designs Through-hardened sleeve teeth, plus hardened nose and keyholes provide outstanding wear resistance Each chuck 100-Percent inspected for performance and precision