On 13/07/2015 10:28, Tim Lamb wrote:
In message , Cursitor Doom
writes
Hi all,

I bought some iffy lathe tool of Ebay; the seller claims it to be
tungsten carbide, but I'm sceptical about that. Looks more like HSS or
chrome/moly to me. I need to ascertain if it's genuine TC or not. So...
how about trying to grind it on an ordinary grey stone grinding wheel? It
should be invincible against grey wheels, should it not? So if I end up
with a bit of the tool ground off, then it can't be TC, can it? Will that
be definitive proof or has anyone got a better suggestion?

For some reason my newsreader has put Chris Hogg in the kill file
(although not found there).

Tungsten carbide tipped tools can be sharpened on a conventional
grinding albeit ...slowly:-)

I was never a grinding engineer but, don't green wheels simply have more
sulphur lubricant than conventional?

It was explained to me that soft wheels, where the grinding material was
"renewed" during usage, were used for Tungsten Carbide, and harder
grinding material used for steels that were softer.