CELESA BLUE-MASTER self-tightening (keyless) industrial chucks for column or CNC drilling machines. Do not require a key for tightening or loosening. They incorporate a self-tightening feature that causes them to grip tighter as more torque is applied. Product line includes high precision (DC1), industrial (DC2) and industrial light-weight (DC3) chucks of different min/max openings of jaws, arbors (A), arbor diameters (D2) and chuck lengths (L1) in mm. Please refer to the illustrated models.