I got a box of collets and this came  in it.

what is it?  and does it have to do with collets?

DSCF6549 by Skip Albright, on Flickr

DSCF6547 by Skip Albright, on Flickr

Maybe a tool for grinding high speed steel tool bits on a surface grinder?  It almost looks like it should fit a collet if the piece with the clamping bolts is removed but hard to tell. I have ran across a few different collet indexers lately but nothing quite the same.

I think that might have originally been used on a tool cutter grinder such as those used in machine shops for sharpening cutters, bits etc...

UB has it correct for the first picture.  I'm wanting to say belongs to a very early K O Lee T & C grinder.  There were many early T & C grinders made in the 30's-40's, and could be for another brand.

The second picture is a 5C square collet block with a assortment of 5C collets.  This collet block can be used on a surface grinder or T & C grinder or in the mill.  I use mine in the mill.  I have a hex one that I use to hold small things in the lathe, too.

Ken