"Harold and Susan Vordos" wrote:

Also. I've just bought a new slower speed grinder (1425 rpm - 4-pole
on 50Hz) with a gray GP wheel and a white alumina wheel. Which would
be the best for touching up carbide-tipped lathe tools?

Neither one.

While I don't recommend them, aside from diamond or CBN, only a silicon
carbide wheel will perform with any degree of satisfaction on carbide.
Aluminum oxide (both of your wheels are aluminum oxide) is far too soft to
be effective.

If you want really good results, buy a diamond wheel, and run it wet.
Otherwise, a green silicon carbide wheel will work.


I tried a green wheel once and took Harolds advice and bought a diamond
wheel. Like night and day. The carbide isn't chipped with the diamond
unlike it was with green wheel.

Wes