Finishing each side of the edge at different grits or "differential grit sharpening"

[Wagnum]

I'm not %100 sure the title is clear. Let's say you've finished sharpening on a 4000 grit stone, you have a nice edge. Now you take out a 500-800ish grit stone and do a few stropping strokes on the back side of your edge. Is there any benefit to this? I heard about it while watching a video Knifewear posted, no specific grits or methods were mentioned but it seems interesting. I sharpened one of my knives like this but have yet to be able to test it on anything but paper. The think idea is you get good bite while still having decent refinement. It sounds a little dubious to me but definitely worth trying out.

What are your thoughts on this? Have you tried it? Heard about it? Apparently, according to Naoto from Knifewear who has direct contact with him so I have no reason not to believe it, Takayuki Shibata does this

 

[Wagnum]

Here's the livestream they did on it. It's long winded (it's a livestream after all) and doesn't actually show the differential grit sharpening, just a regular sharpening

I should mention, I couldn't be bothered to watch the entire video. There's only so many times you can watch someone do/explain a regular sharpening session and that seems to be a large portion of the video. He mentions it in the beginning but when he started to describe a regular sharpening session my ADD wouldn't allow me to pay attention anymore so I skimmed

 

[Pie]

There’s at least one other sharpener that does that out of takefu.. I can’t interpret his stamp so I’m not sure who it is.

Science of sharp also did an article on this - tldr is that it likely doesn’t make a big (if any) difference. There’s SEM photos there tho if it interests you.

I can’t imagine a world where this would be a life changing technique. I’m sure there’s a reason why masashi does it but I personally don’t see much benefit at my stage in the game.

 

[Wagnum]

I can’t imagine a world where this would be a life changing technique.

This is exactly what I was thinking. If it was truly something special it's unlikely that I would have gone this long without at least hearing about it. I get the feeling that it's just more sharpening mysticism

 

[M1k3]

I've tried this. Many different combinations. 120 and 500/4k/12k, 500 and 4k/12k, lastly 4k/12k. No real difference in edge retention that I noticed.

Now, sharpening on SP 120 and then a few strokes on SP 12k worked pretty good.

 

[Wagnum]

Upon further review of the video I noticed he does go over his technique for differential sharpening. Instead of going back down in grit like I did he just steps the grit up on one side, leaving the other side at 1000. I'm definitely curious enough that I'm going to mess around with it a bit

 

[Cliff]

Bernal has a short-ish video, which I can't find again, talking about this on a very asymetrical honesuki. I've tried it but didn't see any benefit.

 

[MowgFace]

Like others, tried with no real noticeable benefits.

Two ways:
Finished regular progression, then dropped back down to a selected grit. (.5K, .8K, 1K, 2K)

Never changed the left face stone after which ever grit I chose (.5K, .8K, 1K, 2K)

I’ve since gotten more stones, but never tried again. If I remember correctly it almost always just felt like the lower grit edge.

 

[Cliff]

For mine, I finished the right hand side, the edge of a >90/10 honesuki at 500 or 1K and the back side with a Belgian Blue. Didn't really make a difference.

 

[Greasylake]

Seems sort of like what I do with uraoshi sharpening when sharpening yanagiba. After sharpening on whatever stone I'm using I'll debur the ura on my finishing stone. I find it just leaves a higher grit edge than whatever the previous stone would have normally been. Not sure there's really any advantage to doing this with your normal sharpening though

 

[Cliff]

That's the idea, and with a honesuki, it's pretty close to a single bevel.

 

[pavhav]

I’m sure there’s a reason why masashi does it

Where did you see/read about that? I have a 180mm SLD nakiri of his from A-Frames and it probably has one of the best OOTB edges I've experienced. Have yet to sharpen it honestly - it just keeps giving.

Now, sharpening on SP 120 and then a few strokes on SP 12k worked pretty good.

Just edge leading with the 12K? I don't have a SP120, but may try with a SG500 instead.

 

[M1k3]

Where did you see/read about that? I have a 180mm SLD nakiri of his from A-Frames and it probably has one of the best OOTB edges I've experienced. Have yet to sharpen it honestly - it just keeps giving.

Just edge leading with the 12K? I don't have a SP120, but may try with a SG500 instead.

Yes, edge leading on simpler steel, a little scrubbing action on on Z-wear. SG 500 will work also. End of the day though, I just maintain the edge with a SG 4k or Venev 800.

 

[jedy617]

Check this out, great video talking about this principle:

 

[Matt Jacobs]

I tried sharpening this way for a while. I went with a chosera 800, fully sharpening and burr removal. I then did a decent amount of edge leading passes on a Rikka 5k on one side only. At first I thought I hit the holy grail. After a bit of usage though I realized there wasnt really a big difference. I think I just really focused with good technique and had really good edges. I could maybe see if for a specific purpose but for general use I cant see the benefit vs good technique on your favorite stones.

 

[inferno]

I'm not %100 sure the title is clear. Let's say you've finished sharpening on a 4000 grit stone, you have a nice edge. Now you take out a 500-800ish grit stone and do a few stropping strokes on the back side of your edge. Is there any benefit to this? I heard about it while watching a video Knifewear posted, no specific grits or methods were mentioned but it seems interesting. I sharpened one of my knives like this but have yet to be able to test it on anything but paper. The think idea is you get good bite while still having decent refinement. It sounds a little dubious to me but definitely worth trying out.

What are your thoughts on this? Have you tried it? Heard about it? Apparently, according to Naoto from Knifewear who has direct contact with him so I have no reason not to believe it, Takayuki Shibata does this

the only thing it does is create a quite sh1tty edge. as proved by science.

READ and understand
https://scienceofsharp.com/2021/06/15/dual-grit-sharpening/

 

[Wagnum]

the only thing it does is create a quite sh1tty edge

This is what I noticed today at work. Not sure I'm going to experiment with it anymore

 

[Greenbriel]

Shibata-san sharpens Masakage Koishis (or at least he used to) with 800 on one side and 8000 on the other (I chatted with Ellie at Knifewear about it). Those knives are (unsurprisingly) screaming sharp OOTB but I wouldn't say any more so than other well-sharpened new knives.

 

[Wagnum]

Shibata-san sharpens Masakage Koishis (or at least he used to) with 800 on one side and 8000 on the other (I chatted with Ellie at Knifewear about it). Those knives are (unsurprisingly) screaming sharp OOTB but I wouldn't say any more so than other well-sharpened new knives.

Does that day more about the sharpener or the technique? Hard to say

 

[MowgFace]

Shibata-san sharpens Masakage Koishis (or at least he used to) with 800 on one side and 8000 on the other (I chatted with Ellie at Knifewear about it). Those knives are (unsurprisingly) screaming sharp OOTB but I wouldn't say any more so than other well-sharpened new knives.

Not questioning Masahi/Shibata-san's integrity or technique whatsoever, but as a function of costs if I sold knives and found a way to not have to sharpen one side of a knife with multiple stones and still produce high quality edges, id do it in an instant.

Saving your consumables (stones), and reducing your run time. Sounds like as long as the customer doesnt hate the edge, its a sound business move lol.

 

[Greenbriel]

Does that day more about the sharpener or the technique? Hard to say

Very true. That's why I said "unsurprisingly" You could probably give Takayuki Shibata a brick and a Ginsu knife and get back a razor.

 

[Rideon66]

So this one seems a bit different from what I have seen and read on the differential grit sharpening. He states it has been witnessed that Shibata would take a sujihiki up to 8K and then do the 3 strop motion on an 800 on one side.
What are the thoughts on this. Stropping one side on a low grit after polishing the knife to say 8K?