Quote Originally Posted by tonyfoale View Post
That explains a lot. The forum does not allow deletion of posts so I edited it to remove the irrelevant content. My comments about using soft jaws as the basis is still valid. Thanks for pointing out my misunderstanding.
Yes, soft jaws would have been easier for him to make the modifications to. I don't recall ever seeing any for chucks which do not have removable top jaws. Maybe there are jaws available that are only have the scroll teeth hardened.
This brings up another interesting point. After annealing a hardened jaw and machining for the grub screws what guarantee the proper hardness could be returned to scroll teeth