Description:

The screws that move the jaws are 20 threads per inch (T.P.I.). A complete revolution is .050". If you keep this number in mind when indicating a part in, it can speed up the process.

First, use the lines machined on the face of the chuck to roughly align the part concentric with the chuck. With an indicator, read the run-out. Move the jaw closest to the high or low point 30% of the total indicator reading in the proper direction.
NOTE: We recommend the 30% figure because the high point of a part will very seldom line up with a jaw. Moving a jaw too much can cause "chasing your tail", or simply moving the high point around the chuck.