Stephen has brought this to us :
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 bigger the better then, if you intend to do many. 8" as a minimum.

The SDS is a different beast. Probably a 6" would do for that, but it
will need a special wheel called a green grit wheel. The normal
blue/grey will not even mark the carbide edge.

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?

Yes, certainly for this size of grinder.


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?

The 6" is better suited for drill bits and HSS lathe bits. The 8" does
the courser and heavier work and is twice the power.


Thanks.

No problem.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk