RE: Ballscrew machining, FAQ

Yes you should buy a 39/64 collet, because one should never pass the opportunity to justify buying a new tool

For now you can wrap the screw with some .008 or .009 shim stock and get by with the 5/8 collet.
A single full wrap with a narrow seam gap will be a pain to load, but will do the job.


5C collets will spring quite a way, but the holding power and accuracy fall off fast past a couple of thousandths.

Charles Hopkins




Problem is the screw is .508" in diameter, too small for a 5/8"
collet. Given that it's a screw, I don't see any easy way to indicate
it in in a four jaw chuck, and my three jaw is ready for the scrap
heap. Looks like it's time to place an order for a 39/64" collet,
which would be .609375". What is the gripping range of a 5c collet
anyway? I'd try tape and the 5/8", but not sure how accurate the
results would be.