When I stripped, cleaned and oiled my 4 jaw lathe chuck today, (it is a Buernard chuck as fitted to a Myford ML7,) I noticed that the jaws and their slots were all numbered, presumably to ensure they are fitted together in the correct pairings. My question is why? I understand the reason for doing it on a self-centering 3 jaw chuck, but since the 4 jaws all operate independently it seems to me that as long as the threads are identical it should not matter which jaw goes in which slot. Can anybody explain?
The other thing that occured to me was how difficult it was to clean the tiny bits of swarf from the female thread in the backplate. Even gouging with a fine 1.0 mm screwdriver still left muck behind. Would a tap be a good idea or would it enlarge the thread?
Cliff Coggin.