These chucks work on the principle of master jaw collets. Their interchangeable collets exert both radial force and axial pull, thus drawing the job against the face of the chuck. They are designed to be stable and maintain accuracy for a very long time. The jaw guides are cylindrical in shape with perfect lapping fit. All these features permit the chucks to operate at very high speeds without any appreciable loss in grip due to centrifugal forces.
The large jaw stroke and easy insertion and removal of jaw inserts make these chucks very versatile. However, like the collet chucks, these chucks are useful only for external gripping. These chucks are excellent for gear blank turning, bearing race turning, where floor to floor time are measured in seconds.