These heavy duty work supports are ideal for preventing the workpiece from chattering and deflecting. The support plunger can be raised or lowered by turning the cap screw. The ball screw that holds the piston supporting the workpiece is available with an optional anti-rotation feature which prevents accidental reversal of the hemispherical tip. Body made from 1045 steel with a black oxide finish. Piston made from quenched and tempered SK95 steel with a black oxide finish.