Jacobs 14442 34-02 1/2-Inch Heavy Duty Plain Bearing Keyed Chuck with No.02 Jacobs Taper Mount Heavy duty models for taper mounting; 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