On Feb 18, 11:15 pm, Jim Wilkins wrote:

The difference is between holding the hot bit versus the grinder.

Jim Wilkins.

I just hold the bit in my fingers. The only time you really hog the
metal is when you are starting with a new piece that has never been
ground. And a new bit is fairly long. So you hold it in your
fingers, and when it get too hot, you drop it in the water container
right in front of the grinder. Sure you may get some surface cracks,
but you are going to do some finish grinding on the fine wheel. So it
makes no difference. Tool steel does not conduct heat as well as
plain steel, so you can get the end being ground pretty hot without
burning your fingers.

Well at least that is what I do. I ground a lot of bits before I ever
owned an angle grinder, so that is what I got used to. The bench
grinder I first used was a belt driven 8 inch grinder that W.W.
Grainger used to sell. So the wheels were bigger than the common 6
inch grinders, and the wheel rpm was between 3400 and 1750. Which made
the surface feet per minute about right for an 8 inch wheel.

Dan