Probably a dumb question about sharpening, but here it goes anyway

[Augusto Orosco]

So, thinking about sharpening theory, this thought crossed my mind: We have heard again and again sharpening is the intersection of two flat surfaces. In order to accomplish this, when first preparing a blade (chisel/plane) we make sure the back gets flat -at least the edge of it- and then we forget about it. The next of our days will be spent working on the bevel and then simply chasing away the burr on the back. The bevel can be sharpened using any number of techniques, of course; from guides to different ways of doing it free-hand, and much effort goes into perfecting ones technique to achieve a good edge.

But going back to the idea of the two intersecting flat surfaces, I wonder why does it matter which side we work on restoring the edge? Can't we reverse the equation and "flatten" the bevel the very first time we get a chisel/plane and never worry about it ever again (say, using a guide of free hand if we know how to); and from then on simply 're-sharpen' the back every time and only chase the burr away on the bevel? If this procedure is equivalent in terms of sharpening, then we would have the advantage of not having to worry about getting the angle right if we want to free hand it: We simply put the back flat on the stone (just the very end of it, or perhaps using the ruler trick, so we are only working a little bit of metal) and go at it.

Anyway, probably a dumb idea and there's something I am missing here; perhaps regarding the physics of the cutting action, or something obvious that my amateur mind cant grasp. So, what do you think? I really appreciate the expertise of the folks in this forum, so please don't hold back when explaining why this won't work and/or is less practical than sharpening the other way.

[David Weaver]

When there is significant wear on an edge, and especially if there's chipping, it's far easier to remove it from the bevel side than it is from the flat side. You just wouldn't be able to keep up with the wear if you attempted to only remove metal from the flat side, even if you chased the burr on the bevel side with a finish stone. you could do it for a little bit, though, but not very long.

[Chris Griggs]

1) When you grind/hone the bevel you are grinding "back" the edge...removing material inward to get past the wear. If you tried to do this only on the back you would only be grinding up into the blade and you would need to make the blade thinner vs shorter each time.

2) Even though the bulk of the material removal occurs on the bevel. You really should do more than just "remove the burr" when you rehone a blade. The back does wear so taking a handful or strokes are your finest stone keeps that surface refined, and give you a better edge.

[Augusto Orosco]

When there is significant wear on an edge, and especially if there's chipping, it's far easier to remove it from the bevel side than it is from the flat side. You just wouldn't be able to keep up with the wear if you attempted to only remove metal from the flat side, even if you chased the burr on the bevel side with a finish stone. you could do it for a little bit, though, but not very long.


1) When you grind/hone the bevel you are grinding "back" the edge...removing material inward to get past the wear. If you tried to do this only on the back you would only be grinding up into the blade and you would need to make the blade thinner vs shorter each time.

2) Even though the bulk of the material removal occurs on the bevel. You really should do more than just "remove the burr" when you rehone a blade. The back does wear so taking a handful or strokes are your finest stone keeps that surface refined, and give you a better edge.

Got it. Thanks to both!

[Roy Lindberry]

My two cents:

In short, working the back would require one of three things:

1) honing the entire back, which requires that you remove a lot more steel with each sharpening and increases time spent tremendously;

2) honing only a specified amount on the edge (1/4", 1/2" etc. ) which would eventually result in a "stair step" on the edge of the blade. When the blade got too thin, this would have to be removed, and a new bevel ground on the edge. The other problem is that it would become impossible to register your chisel against anything longer than the specified distance;

3) honing the back at a bevel, which would defeat the entire purpose and gradually increase the surface area, giving you the same problem as #1.

All of these would result in a thinner chisel over time. Hope this makes sense.