‎•Jaws Center-Ground for Absolute Straightness and Alignment. •One-Piece Sleeve Eliminates Crack Between Driving Teeth Often Found in Other Designs. •Through-Hardened Sleeve Teeth, Plus Hardened Nose and Keyholes Provide Outstanding Wear Resistance. •Each Chuck 100% Inspected for Performance and Precision. •T.I.R. .004″ Maximum at Half Capacity. •Kd Models Have Keyed Drive Feature •Pd Models Have Pin Drive Feature •34-33C Has Smooth Sleeve with Locking Collar.