CNC keyless drill chucks are keyless drill chucks with BT shank, a straight shank, and the Morse taper shank, and the run-out accuracy stable even if the holding diameter is changed, since the keyless drill chucks have a shank and perfect integral type structure. For chucking drill bit, tighten the sleeve by hands and then re-tighten the sleeve with the attached spanner, which will make the gripping torque three times stronger than the tightening by hands only. Also this re-tightening with the spanner prevents loosening of the sleeve at an emergency stoppage of the main spindle and thus no falling-down of the drill bit from the chuck.

The head of a keyless drill chuck and BT shank has solid construction, and it is proud of the run-out accuracy of 0.002 inch or less, and preeminent deflection accuracy. Moreover, since it is full inspecting, high quality is guaranteed.