Northfield Precision Instrument Corp., a leader in the design and manufacture of precision workholding chucks, introduces their Model 1000 10"-dia. "Pitch Line" chuck. This chuck grips the O.D. of 9"-dia. helical gears. The pins are mounted in a loose fitting housing so they can float. The pins pick up the pitch diameter and the jaws grip the OD of the pins. The pitch is measured over pins, so it is gripping the same way it measures. The Model 1000 shown 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 (3) 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. Available in SAE or metric, in sizes from 3" (76mm) to 18" (457mm). Accuracies of 0.001" to 0.00001" guaranteed. Custom workholding chucks and jaws are available and free engineering assistance is offered.