Northfield Precision Instrument Corporation, a designer and manufacturer of precision workholding chucks, recently introduced their Model 470 chuck, which was retooled for Caterpillar. The part is a "Wheel Poppet Adapter." This chuck has special serrated insert pads to securely grip the part during the drilling operation. The chuck is mounted on an indexing head to expose both sides of the part for drilling. The plates attached to the sides of the jaws are used as a datum for drilling; one plate flexes to push the part such that it maintains positive contact against the solid plate for location. The chuck also has an axial locator mounted in the center with line contact so as not to influence the grip of the part, but acts as a secondary datum.