On Thu, 02 Mar 2006 00:40:46 GMT, Jerry Martes wrote:

"Ned Simmons" wrote in message
...

I think it has to do with the fact that the ring with the teeth is not a
perfect fit on the chuck body. Tightening the chuck tends to cock the
ring a bit so it doesn't turn as freely. Moving the key to a different
hole pushes on a different point on the ring and frees it up.

I'd bet you have the right idea. That even makes sense.

Yeah, that does have a "ring" to it. We tend to forget that metal does
distort when we're using it. Got a great lesson in that last night with
a 1/8" endmill.