SHARS 6 4 Jaw Independent Lathe Chuck with TIR Certification NEW. Each high quality chuck comes with a. Accuracy is maintained for the entire clamping range. Semi-steel chuck body made from high quality cast iron. Three pinion design with each pinion ground and hardened to HRC 43. Two piece jaw design with a master jaw and a top reversible jaw in American Standard tongue and groove specification. Both side of jaw teeth and guides are ground and hardened to HRC 58-62. Each set of jaws are serialized in their own set. A serialized set of jaws are then finished, ground, and lapped on their designated chuck body which will be the same chuck body on the final assembly to achieve a greater accuracy. Before assembling the jaw to its designated chuck body, the jaw’s finish machining are performed on a closed tolerance state of the art CNC machine from Japan. Scroll plate’s thread flank are ground on both side to achieve a tighter contact with the master jaw. Each chuck has gone through rigorous accuracy and repeatability inspection with clamping and jamming multiple random testing rods or rings. Included 1 set of reversible solid hard jaws. 1 lathe chuck key. Inspection report on runout on both inside and outside jaws.