Precision with Ball Bearing Integrated Shank 100% of these drill chucks is individually controlled to ensure a maximum total indicator run-out of .0016". The self-tightening mechanism automatically increases the clamping forces in proportion to the increase in torque during the drilling operation. This prevents tool slippage in a clockwise rotation. Engineered with milled flats for additional gripping torque with a spanner wrench. Light tightening with a wrench increases gripping torque up to 3 times higher than hand tightening. All chucks come with a wrench.
