Northfield Precision Instrument Corporation, a designer and manufacturer of precision workholding chucks, introduces their special Model 6100 3-jaw air chuck. With .0005 T.I.R., this chuck has a 6.42 inch diameter with a 1 inch jaw stroke (.500” per jaw). The chuck was designed with special jaws to grip the customer’s sprocket. This chuck requires special jaw blanks different from the Northfield standard 6 inch series. The adapter plate will also be different than a standard Northfield 6 inch chuck. The air tube, rotary union, operating valve and regulator are the same as all other Northfield chucks.