"Ignoramus32707" wrote in message
...
http://igor.chudov.com/misc/ebay/tmp/tmp-8848.jpg

This is a very strange collet. It looks a lot like 5C and the same
approximate size, but it is left hand threaded and the thread is very
coarse.

It was in that chuck.

Would anyone have any idea what are those called???

Stumped in Illinois

Looks like maybe a screw machine collet of some sort--you might want to
check the southwick & meister site.