rich wrote,on my timestamp of 27/12/2009 9:10 PM:

I have two sets, one from Lee Valley that I have at 25 degrees. I
have another set that I'm thinking of grinding at 30-35 degrees for
removing mortices and other heavier work. Then keeping the Lee Valley
ones for "paring work"? Is this the way to go??? Or do I need to go
looking for a specific "paring chisel"???

Any help will be appreciated.....

Paring chisels usually have a low angle - 25 degrees qualifies - and beveled
sides in an almost flat triangular section. They are traditionally used with
hand force only.

Firmer chisels are similar in size and proportions but have square sides with a
rectangular cross section. You can use them with a low bevel angle like paring
chisels or with a 35 degree angle for general trim work, hand powered or with
the aid of a rawhide or wooden hammer/mallet.

Mortise chisels are traditionally of square section and built very strong to
handle not only the whacking needed to sink the mortise but also to lever out
the chipped bits without losing the edge. As such, they usually have a higher
sharpening angle - 40 degrees or higher - and a very strong build and reinforced
handle to sustain heavy hits with mallets.

Having said all that, there are no absolutes: with very small mortises or
dovetails, it is perfectly possible to use small firmer chisels with small
mallets, or even in some cases paring chisels, sharpened at a higher angle. In
fact with dovetails it is almost mandatory to use a paring chisel! By the same
token you can use a firmer as a paring after sharpening the bevel at the
required angle.

So, pick your choice and what you're comfortable with. Just keep in mind the
bevel angle: 25 degrees for paring, 35 for firmer, 40 for mortising. Then
again: if you miss by a few degrees, your heritage won't be spoiled!
Remember - no absolutes!