On Jun 10, 9:00*am, Randy wrote:
On Wed, 9 Jun 2010 09:17:05 -0700 (PDT), Jim Wilkins
...
It may not actually be undersized. See if the slits warped shut in
hardening. You can jam screwdrivers in to open them when you load or
remove the stock.
jsw

Been there, *was doing that, it's a PITA.
Randy

It is, but more acceptable on the rarely used collets than the common
sizes. I'd buy good ones for 1/2" and 1" at least, probably also for
1/4", 5/16", 3/8", 5/8" and 3/4", and cheaper or used ones for the
other sizes. Those are the sizes of drill rod I keep on hand. A screw
thread held by a collet isn't going to run perfectly true anyway,
though that's a good way to clamp them without damage.

jsw