Not sure where you measure the 8MM the shank is about 8MM it looks to be 40
TPI
"Andrew Mawson" wrote in message
...

"wayne mak" wrote in message
...
I found a few of these collets/arbors in a box they are very small
and have
no markings.
http://www.motherearthrecycling.net/...let/collet.htm



The Quorn Tool & Cutter grinder uses watchmakers 8mm collets in some
varients, and I suspect that is one used for mounting a wheel onto the
main spindle.

AWEM