99/1 Edges

[Alex M.S.]

For highly asymmetric grinds like 99/1 why do we deburr on the “flat” side instead of actually sharpening and trying to form a small burr on the opposite side? At what ratio do we start actually sharpening both sides, about 80/20?

Just curious as to what the rationale is behind this. These 99/1 edged knives aren’t treated like a true double edged grind but they aren’t treated like a single edged grind with a hollow ground ura either. They are unique in their own classification in a sense, am I wrong?

Any input or opinions appreciated.

 

[panda]

Those are junk, why bother.

 

[BloodrootLS]

Those are junk, why bother.

This, or something quite similar is what many honesukis are from what I’ve seen. Seems to have its purpose, no? I also know some very talented pros who use this approach on their slicers. Different strokes for different folks?

 

[Pensacola Tiger]

For highly asymmetric grinds like 99/1 why do we deburr on the “flat” side instead of actually sharpening and trying to form a small burr on the opposite side? At what ratio do we start actually sharpening both sides, about 80/20?

Just curious as to what the rationale is behind this. These 99/1 edged knives aren’t treated like a true double edged grind but they aren’t treated like a single edged grind with a hollow ground ura either. They are unique in their own classification in a sense, am I wrong?

Any input or opinions appreciated.

Because deburring the "1" side of a 99/1 is all that is needed. If you raised a burr, you would have, at best, a 95/5 edge.

From a practical standpoint though, putting a small bevel on the flat side improves edge stability. I have a couple of 99/1 knives (a honesuki and a pettysuki) and I raise the spine just a bit when sharpening the flat side.

 

[Alex M.S.]

Many hankotsu and honesuki have factory 99/1 edges. I suppose this eases getting as close to the bone as possible (IE boning out chicken thighs) without actually gliding along on the bone like a western boning knife.

 

[ThEoRy]

For highly asymmetric grinds like 99/1 why do we deburr on the “flat” side instead of actually sharpening and trying to form a small burr on the opposite side? At what ratio do we start actually sharpening both sides, about 80/20?

Just curious as to what the rationale is behind this. These 99/1 edged knives aren’t treated like a true double edged grind but they aren’t treated like a single edged grind with a hollow ground ura either. They are unique in their own classification in a sense, am I wrong?

Any input or opinions appreciated.

They aren't treated like a traditional double bevel knife because they are different.

They aren't treated like traditional single bevel knife because again they are different.

A few simple edge trailing strokes with the spine clicked up a notch is all that is needed. And in my experience it does generate a burr.

This is what I do.

Those are junk, why bother.

Wrong.