There should be two sets of numbers on quality chuck jaws. A/ 1,2,3,(4) denoting which slot, and B / a serial number that should correspond to the chuck's serial number.
The later number is usually stamped in the recess forming the T section that they slide on. If they don't correspond you have the wrong jaws, if they are not marked it's probably a rubbish chuck
The later number is usually stamped in the recess forming the T section that they slide on. If they don't correspond you have the wrong jaws, if they are not marked it's probably a rubbish chuck