Knife Edge Geometry
Knife Edge Geometry
Having thus far only owned/used/sharpened German knives, I'm curious about the edge geometry on Japanese knives. It looks as though some Japanese knives have a relatively large "edge" as compared to those on Western knives, which I'd guesstimate at 1/32" or less. I've spent substantially more time sharpening woodworking tools which relatively huge edges (and almost exclusively single bevels) which makes sharpening much, much easier.
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ianbiringer
- Posts: 5
- Joined: Mon Dec 25, 2017 9:59 pm
Re: Knife Edge Geometry
Edge `width' is related to the angles at which the blade is sharpened, and to the thickness of the blade at the other end of the bevel. The sharpening angle is usually smaller with Japanese knives, e.g. 10-15 degrees on both sides, since the steel is usually harder and they can support such an edge without it rolling over. In comparison, Western knives are often sharpened at 20 degrees on each side. I wouldn't necessarily say that the edge bevel is usually wider on Japanese knives, though. Often, Japanese knives are thinned enough behind the edge bevel that even with the sharper angle, the width of the bevel is pretty moderate.
Sometimes, you will see "wide bevel" Japanese knives, though, where it looks like the edge bevel is 1cm wide or so. However, depending on how it's sharpened you might have another small bevel right at the edge. (It might even be an extremely small `microbevel' that's not easily visible unless you really look for it.) You can certainly forget about all that and just sharpen these kind of knives like they're (double sided, if applicable) chisels, but that may not be the best for edge retention (a small additional bevel will often prolong the life of the edge) or food release (some wide bevel knives have a sort of convex geometry in the wide bevel that helps prevent food from sticking to the knife).
Sometimes, you will see "wide bevel" Japanese knives, though, where it looks like the edge bevel is 1cm wide or so. However, depending on how it's sharpened you might have another small bevel right at the edge. (It might even be an extremely small `microbevel' that's not easily visible unless you really look for it.) You can certainly forget about all that and just sharpen these kind of knives like they're (double sided, if applicable) chisels, but that may not be the best for edge retention (a small additional bevel will often prolong the life of the edge) or food release (some wide bevel knives have a sort of convex geometry in the wide bevel that helps prevent food from sticking to the knife).