Now that I think about it, I have one of those chucks too, in a lathe. I
don't know where I got it but it was used and always had run-out. I Just
thought it was worn, maybe accuracy is not it's inherent strength. I only
use it when I really, really don't want a bit to spin in it 'cuz I can
tighten the shi* out of it.

"Tidrix" wrote in message
...
In article om, Tom
Gardner wrote:

Does a "Super Chuck" have a key? I tighten my keyed chucks progressivly
in
all three holes twic around. This seems to help me.


It is a Jacobs ball bearing Super Chuck and it has a key. When
tightening with the key I have tried using a single hole as well as all
three holes with similar results.