QUESTION:

I’ve read that the cutting edge of a plane blade should be slightly cambered. Why? And should I do it to all of my plane blades?

Kevin Lavois, Holyoke, MA

ANSWER:

No, you shouldn’t camber all of your blades. Some need to be straight to perform their jobs.

The blade of a shoulder plane or rabbet plane should definitely be left square, because you can’t trim a tenon shoulder square or cut a square rabbet with a rounded blade.

And I keep the blades square on all of my bench planes, except for my smoother. But I do round their corners slightly so that they don’t cut tiny steps into the surface. A straight edge is also easier to maintain, which is an important consideration if you use your bench planes a lot.

But there’s good logic in slightly cambering the blade of a smoothing plane. A cambered blade leaves no marks, and so a cleaner finish, on the surface. The blade only needs a slight camber, just a couple thousandths of an inch. It can be achieved by alternately applying a bit more pressure at each corner when honing.

 

Fine Woodworking Recommended Products

Norton Water Stones

This kit includes everything you need to sharpen all of your blades, with water stones in four grits and a separate stone to keep them flat.

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Honing Compound

This honing compound is great for loading into a buffing wheel and polishing an assortment of metals.

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