On Tue, 22 Sep 2009 18:36:03 +0100, Harry Bloomfield
wrote:

Wood chisels, or some other type of chisel?

Diameter, rather than wide?

Sorry, I was not very clear in my OP. I was talking about cold
chisels, bolster chisels and sds chisel bits, and you and the other
poster are quite right, I meant diameter.

the larger and heavier the wheels, the more power will be needed
to make them turn and grind.

Are they all induction motors, and if not, is induction preferable?

I have one of these, a 6" and an 8" grinder.

Why do you need both a 6" and an 8"? Is one more suited to one task
than another?

Thanks.