Northfield Precision Instrument Corp., a designer and manufacturer of precision workholding chucks, introduces their Model 1000 10 in. diameter Pitch Line chuck. This chuck grips the O.D. of 9" diameter helical gears. The pins are mounted in a loose fitting housing so they can float. They pick up the pitch diameter and the jaws grip the O.D. of the pins. The pitch is measured over pins, so it is gripping the same way it measures. The Model 1000 has two "pin cages," one for a left hand helix and one for a right hand helix. The pin cages are changed out by removing three mounting screws. Northfield Precision designs and manufactures air chucks for any lathe, boring machine, grinder or VMC. Models include through-hole, high-speed and quick-change and are available in SAE or metric, in sizes from 3" (76 mm) to 18" (457 mm). Accuracies of 0.001" to 0.00001" (0.254m) guaranteed. Custom workholding chucks and jaws are available and free engineering assistance is offered.