How To Sharpen Asymmetric Grinds

Eli Chaps

Eli Chaps

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Apr 20, 2018
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I recently acquired an 8.5" chef's knife in BD1N that has what I'd call a 70/30 grind on it.

The only "asymmetric" grinds I've ever messed with were ones that weren't meant to be that way and I was trying to undo what had been done. :)

So, do you folks approach asymmetric grinds basically the same as a 50/50 grind (adjusting for the angles of course)? Meaning, you basically complete the same number of strokes on both sides and what not?

Or, do you approach them more like a single bevel and just knock the burr off the "back" side?

Thanks as always.
 
I don't count strokes. Not every stroke removes the same amount of material, especially when different surface areas are involved between bevels. I watch my scratch pattern to see when I've hit the apex, and do that on both sides.
 
Keep in mind that with Japanese knives, "asymmetrical grind" is not the same thing as an edge bevel that is off-centered.

Usually the entire blade is ground asymmetrically, on purpose, and done differently for right vs. left handed users.

The edge bevel is then also done asymmetrically, to avoid steering and to move the edge to in-line with the center of the asymmetrically ground blade.

Here's a good overview: https://www.kitchenknifeforums.com/threads/a-basic-explanation-of-asymmetry.33951/

The reasons have to do with food release and the ability to make precise, thin cuts in certain types of product.

I would suggest following the factory grind rather than trying to reset the edge bevel to 50/50. That will not affect the primary grind, and may cause steering - tendency of the blade to go to the right (or left) when trying to cut straight through something.
 
jc57 said:
Keep in mind that with Japanese knives, "asymmetrical grind" is not the same thing as an edge bevel that is off-centered.

Usually the entire blade is ground asymmetrically, on purpose, and done differently for right vs. left handed users.

The edge bevel is then also done asymmetrically, to avoid steering and to move the edge to in-line with the center of the asymmetrically ground blade.

Here's a good overview: https://www.kitchenknifeforums.com/threads/a-basic-explanation-of-asymmetry.33951/

The reasons have to do with food release and the ability to make precise, thin cuts in certain types of product.

I would suggest following the factory grind rather than trying to reset the edge bevel to 50/50. That will not affect the primary grind, and may cause steering - tendency of the blade to go to the right (or left) when trying to cut straight through something.
Click to expand...

Understood and all of my research indicates this is indeed intentional. It's a Yaxell Dragon Fire Asian-style (gyuto) knife, not their standard offering.

It is indeed quite slicey and if nothing else, I'm intrigued to experiment with and learn to sharpen this kind of grind.
 
Sometimes it really is just a more acute angle with a wider bevel on the blade face and a more obtuse but narrow bevel on the back of the blade, but otherwise just a normal symmetrical primary grind.

Korin has a description of that type of edge in this little PDF, last page:
http://www.korin.com/site/PDFs/knifesharpeningbasics.pdf

There are several ways to achieve an intentional asymmetrical grind. For example, you can use the same angle on both sides, but spend more time on one side than the other. That results in a off-center edge, but with still equal angles (say 15 degrees per side, relative to the vertical).

Or you could have a perfectly centered edge, but ground at 10 degrees on one side, resulting in a wider edge bevel, and 20 degrees on the other side, resulting in a narrower edge bevel.

Both would be at 30 degrees inclusive, both would be asymmetrical, and both might produce different results in cutting. You can also combine those to have both an off-centered edge which also has different angles.

My understanding is that you are trying to eliminate steering, reduce wedging, and improve food release, and this will vary depending on what you are cutting and your technique.

For me personally, just getting an edge sharp is an achievement, and I am happy with a 50:50 symmetrical grind, which is what my knives came with from the factory.
 
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