Collet Identification Help

[Dale Lusby]

I picked up a bunch of collets today and there are two that I'm not sure what kind they are. They are 3.5" long and .8125 wide (approximate as I don't have my calipers with me). One is a Porst Bros of Chicago and the other is a Rivett and says 4 NS on it. Is the 4 NS the kind of collet? I haven't heard of this one and didn't see anything when I searched. Can anyone help me identify what type of collet as well as an idea of which machines have the same?
Thanks,
Dale

[reggie_obe]

4NS is the designation. Rivett 608 is one machine that uses these, probably are others. See: http://shopswarf.orconhosting.net.nz/colletap.html

[squirrel]

The old Gorton drill grinder uses these, how ever most of them are in your new car body or neighbors steel siding.

[lane]

the NS means new style .As said Gorton cutter grinders used then and some old lathes.