The Hollow-ground Bevel — What's the Big Deal?

The phrase “hollow-ground bevel” has been widely misused, and I’d like to set the record straight as to what it is, what it’s good for, and when to avoid it. A hollow-ground bevel is simply a concave bevel. It’s a natural result of using a grinding wheel. The wheel is convex, of course, so it always creates a bevel that’s concave.

A tool with a hollow-ground bevel is easier to sharpen by hand, without the use of a jig. The biggest problem with honing by hand is holding the tool at the correct angle with every stroke. A hollowground bevel helps you find and maintain that angle, so there’s no wasted effort.

With a hollow grind, you simply rock the tool up and down until it locks in place, resting on the bevel’s heel and toe. Two points of support make the difference—it is much harder to feel the correct angle if the bevel were flat, rather than concave. That is why we have arches in our feet—they make balancing easier. I often sharpen chisels by hand, without a jig, simply because it’s so easy. Ditto for plow plane and rabbeting plane irons that are awkward or impossible to hold in a jig. I do use a jig for honing standard-thickness bench plan irons, though. Even with a hollow-grind, their bevels are too narrow for me to maintain that correct angle with every pass on the stone.

OK, so when is a hollow-ground bevel not appropriate? Japanese tools and Western mortising chisels are exceptions. Ideally, Japanese tools should be ground with a flat bevel, to maximize support of the tip. The steel of Japanese tools can be brittle, and without adequate support, a tip could fracture. Mortising chisels should be flat ground too, or made slightly convex, for the same reason. To withstand heavy blows, their tips need to be as strong as possible.