My observation is, coarse stones bite far more easily into tomato skin and other smooth surfaces. I'm not sure if it's the size of the cells compared to the size of the microscopic teeth of the steel or something. Same with me cutting myself by accident. A fine edge will flay me without me feeling it. But with a coarser edge (
Very interesting - I loooooove me these knife nerdy sharpening videos with Naoto!! I will have to try this for sure next time I get to sharpen my knives!
It looks like the coarse grit sharpening should be on the left side for right handed chefs. I've got a Bunks to give that a try. Good experiment. Thanks
That is what I am thinking. Especially on asymmetrical knives. The right side would have its larger bevel nicely polished, while the left side’s smaller bevel is left coarse. I am going to test this on my Misono.
I thought it should be the other way around. So that it's like a serrated blade and the smoother cutting edge would be closer to your hand holding the food. This test might work better for single bevel edge. My thoughts on this comes from what i see from mainly on one sided serrated edges, tape dispenser blades,and hand planes that have serrated edges for bulk removal. For right handed people the smooth side should be on the left/inner side I think. So that the cutting edge would be beveled more towards to the left. Making it more flush with the down cut, and the rougher/coarse side should be the one pushing the food away. the lower the grit the more bite the blade will be. But I think making one side smoother almost makes the knife angle narrower in a sense. I think that might be the benefit of single bevel knives, or the benefits of having asymmetric blades. I'm assuming for right handed people the right side pushing food away is grounded down more.
If i need a toothy edge, i sharpen my sujihiki with a shapton 320 on both sides, do a few edge leading strokes after that, then i jump up to the shapton 5k, polish only the right side, to finish off i do some edge leading strokes on both sides and a few pulls on the chrome oxide leather strop. Gets me a super aggressive edge for meat, sausages, tomatoes, peppers etc. Edge retention is great with this technique. Works great on sg2/r2, aogami 1,2 and super, not so good on finer purer steels like shirogami 1,2,3 and ginsan or sandvik steels (i guess the grain structures are to fine on these type of steels) it works but not as good than on the other mentioned ones....
I normally do an edge on shapton pro 2000 and I then do low pressure edge leading strokes on both sides on a natural ( aiiwatani koppa lv3), finally stropped on newspaper and linen and I get a healthy amount of bite while passing hht test, this having still good push cutting abilities. I will try next switching strokes angles on the other side and maybe do dual sides like shibata does, curious about the results. In any case thanks for sharing this !
I never tried differential grit sharpening but it's clear to me vegetables respond well to an agressive toothy edge. An 800 grit edge will not slip on tomato skin, not a bit. Polished edge makes sense for vegetables if you want glossy cut for high cousine but otherwise a low grit stone finish that is able to shave hair and cut paper towel will perform better. Low grit will have better performance on vegetables, barbecue crunchy fat and rope. High polish will perform better on raw meat, paper, hair and impact knives. Japanese tradition to separate vegetable knife from the raw meat knife makes a lot of sense to me.
There is a comparison to an 8k finish both sides, but no comparison to a 1k both sides. I'd like to see 4k compared as well. This only shows that a coarse edge works better than fine on a tomato, which is widely accepted. Who cuts a carrot like that? And there was no push cutting test, which is the main reason I would consider doing extra work to do a hybrid edge - to balance slicing aggression with push cutting smoothness.
It should be the same effect whichever side you do it on! Differential sharpening is more about the contrast between grit sizes rather than where they are, if that makes sense. Good question!
Always interesting to me how in this day and age, something as primitive as sharpening still seems to have some controversy as to exactly how it works and what is the optimal approach.
I think that as steels get more complex along with sharpening tools. The more complex simple sharpening gets. Some steels take well too certain grits and even approaches while others you need to be much more careful with during their process. True master sharpener’s know what works for them based on the steels given to them. I have been sharpening for years and only recently have I discovered that no steel and even blade is alike. With anything it’s feel and practice as well as trying our new ways and approaches.
Gabriel L Yeah, that does make sense to me. I guess that at least partly explains it. And there are a lot of things that are understood to some degree to be fair. It's just that when sharpening has been examined to the level of detail capable with a scanning electron microscope and still some of the basic mechanics involved seem elusive and half understood it is interesting, but I guess there are a lot of things like that. Perhaps part of what makes it fun to follow and learn about though.
I suspect that in your test 1000/1000 or 500/500 would have had superior cut speed. However the rougher grit edges would probably have had less longevity
This is a tricky one- depends a lot on the steel and how you're sharpening, but even then we hear a lot of contesting opinions about which grit dulls faster! Maybe a good topic for a future video.
I kinda hate the results in this video, my ocd for sure wants 8k x 8k to work the best. Great video and content as always, Naoto is a beast. Thx to everyone at Knifewear🔪
I enjoyed this video. I wonder if changing the sharpening process slightly would make any difference in the results. In this video I believe you sharpened both sides with the lower grit then proceeded to polish one side up to a higher grit. I think this might have the effect of polishing out the toothiness on the cutting edge. What if you were to sharpen both sides, polish one side on a high grit then go back and make some stropping passes on the low grit side of the blade to re-establish the toothy edge?
The idea is to create large teeth on one side, and smaller ones in between on the other side, and it's the contrast that tends to make for a better cutting experience and lasting edge- I suspect stropping on that lower grit stone again would be a bit self-defeating. Try it out and let us know how it goes!
I stopped going above 5k on any knife when I heard a 1st mate on a charter fisher who cut chum to the tune of about 200 fish a day say the finer the grit used the more polished the edge became and the more it rode on top of the fish and didn't bite in. Usually I actually stop at the naniwa green "brick of joy" 2k for 99% of my knives. Maybe you could try doing the winner differential grit sharpening on the tomato with the grit sides reversed to see if that makes a difference. Test a left side low grit right side polish vs a right side low grit and left side polish.
@@thiago.assumpcao I agree but those are sushi or sashimi knives specifically for raw fish meat and not scales. My general purpose knives like my Santoku, Dojo Blue fruit knife and even my Deba do much better with a 2k finish.
@@82delta My general purpose knives I like to keep around 1K but if it's dedicated to meat I prefer high polish. I don't cut fish much, I wonder if there's a difference.
Great video Naoto. Does the type of steel make a difference? Would a steel like W2 versus something with carbides and more natural bite need different grits to achieve the same effects?
Great question! Each would likely start identical with the same grits, but steels like SLD or W1 age very differently from something like VG10 or R2. More testing and research required... stay tuned!
@@KnifewearKnives Can you try to reverse the coarse and smooth side in the video? I think it should be the other way around so the pointy sides bites into the food more. From this video I think the coarse grit is beveling the serrations away from the food.
Cutting is really tearing at the microscopic level. Put it under the microscope and you will see the 1000/8000 has micro-serrations of the correct size to "pierce and grab" the tomato skin while the 500/10,000 has teeth that grab the coarser carrot. The 8k/8k just doesn't have teeth large enough to pierce/grab either.
Exactly! This is just making an irregular serrated edge. My expectation is that, if you push cut paper, the uneven grit knives would be rougher in feel corresponding to the lowest grit. Polishing the other side makes sharp spots at the high points on the edge but might not remove enough metal to get the gullies unless you really get after it. Serrations are great for grabbing into, and tearing out, smooth surfaces. I still prefer a perfect high grit edge on most kitchen tasks but it does require more maintenance as it is subject to deformation and wear, where a serrated blade dulls mostly from wear and less from apex deformation.
I absolutely hate how my Masakage was sharpened out of the box. The concave in the bevel that is present from the wheel used drives me absolutely up the wall.
I sharpen this way too!!! I usually with 250 grit on one side and 6000 the other. Thanks for sharing this! This is my original method, I did not know there were others doing it. I call it “dual grit” but “differential grit” is a good name too: ua-cam.com/video/FruwVRSmhWA/v-deo.html
And this is a video where Pete from Cedric& Ada tests a knife with this edge in CPM M4, and it beats his previous record by about 50%: ua-cam.com/video/jPIJkXfUg5E/v-deo.html
@@KnifewearKnives yeah, your method and testing is so cool too! I would love to see more experiments! I am testing now to see if it works better on some steels/certain grits/particular abrasives.
If my knives are hair whittling sharp using the regular method everyone uses, why would I change to using different grits on different sides? It's just wanking with steel. I'd like to have seen how a 1000/1000 cuts on that tomato.
Originally posted from 'Sharpe like Shibata-San KW video: Here's the deal...sharpen both edges to your highest grit (mine is #6000), for traditional Japanese steels (AS,A1, A2, S1, S2). Then, make 10 stropping passes on your outside edge (right side for right handlers), with your 'sharpening stone' grit, (I use #1000), with 3 passes back and forth out of the 10 - (I use pass 6-8). That will give you nearly the sharpest edge currently possible from hand sharpening. Note: I am am also using an asymmetrical bevel for my blades @ an approx. ratio of 80:20@20'=16':4'' (right handed-bias). Also note: Shibata-San does this currently with: #8000\#800, which I have not yet tried as I do not own those #'s.
My observation is, coarse stones bite far more easily into tomato skin and other smooth surfaces. I'm not sure if it's the size of the cells compared to the size of the microscopic teeth of the steel or something.
Same with me cutting myself by accident. A fine edge will flay me without me feeling it. But with a coarser edge (
Very interesting - I loooooove me these knife nerdy sharpening videos with Naoto!! I will have to try this for sure next time I get to sharpen my knives!
Happy to hear it!
This is an Excellent test......I have been considering a single bevel blade purchase for the last 3yrs and had concerns about how to keep it sharp
It looks like the coarse grit sharpening should be on the left side for right handed chefs.
I've got a Bunks to give that a try.
Good experiment. Thanks
That is what I am thinking. Especially on asymmetrical knives. The right side would have its larger bevel nicely polished, while the left side’s smaller bevel is left coarse. I am going to test this on my Misono.
That was a question I was going to ask. Which side of blade get's the coarser grit for right handed users?
I thought it should be the other way around. So that it's like a serrated blade and the smoother cutting edge would be closer to your hand holding the food. This test might work better for single bevel edge. My thoughts on this comes from what i see from mainly on one sided serrated edges, tape dispenser blades,and hand planes that have serrated edges for bulk removal. For right handed people the smooth side should be on the left/inner side I think. So that the cutting edge would be beveled more towards to the left. Making it more flush with the down cut, and the rougher/coarse side should be the one pushing the food away. the lower the grit the more bite the blade will be. But I think making one side smoother almost makes the knife angle narrower in a sense. I think that might be the benefit of single bevel knives, or the benefits of having asymmetric blades. I'm assuming for right handed people the right side pushing food away is grounded down more.
Might want to do a long term test with those grits.
If i need a toothy edge, i sharpen my sujihiki with a shapton 320 on both sides, do a few edge leading strokes after that, then i jump up to the shapton 5k, polish only the right side, to finish off i do some edge leading strokes on both sides and a few pulls on the chrome oxide leather strop. Gets me a super aggressive edge for meat, sausages, tomatoes, peppers etc. Edge retention is great with this technique. Works great on sg2/r2, aogami 1,2 and super, not so good on finer purer steels like shirogami 1,2,3 and ginsan or sandvik steels (i guess the grain structures are to fine on these type of steels) it works but not as good than on the other mentioned ones....
I normally do an edge on shapton pro 2000 and I then do low pressure edge leading strokes on both sides on a natural ( aiiwatani koppa lv3), finally stropped on newspaper and linen and I get a healthy amount of bite while passing hht test, this having still good push cutting abilities. I will try next switching strokes angles on the other side and maybe do dual sides like shibata does, curious about the results. In any case thanks for sharing this !
CROSS EDGE... !!!! Damn..!! Why didnt i think of that logical before..! Thank you so much Naoto.. arigato gozaimasu.. 🙏🏼🙏🏼🙏🏼
I never tried differential grit sharpening but it's clear to me vegetables respond well to an agressive toothy edge. An 800 grit edge will not slip on tomato skin, not a bit.
Polished edge makes sense for vegetables if you want glossy cut for high cousine but otherwise a low grit stone finish that is able to shave hair and cut paper towel will perform better.
Low grit will have better performance on vegetables, barbecue crunchy fat and rope.
High polish will perform better on raw meat, paper, hair and impact knives.
Japanese tradition to separate vegetable knife from the raw meat knife makes a lot of sense to me.
In your right-handed usage, is the coarser grit edge facing your body or facing away/outward?
Either works!
There is a comparison to an 8k finish both sides, but no comparison to a 1k both sides. I'd like to see 4k compared as well. This only shows that a coarse edge works better than fine on a tomato, which is widely accepted. Who cuts a carrot like that? And there was no push cutting test, which is the main reason I would consider doing extra work to do a hybrid edge - to balance slicing aggression with push cutting smoothness.
Well have the do another video to compare more grit combos and do more tests!
If you’re a right handed person does the high grit side go on the left or right?
I was thinking the same
I think it should be the left side, but I think the video does the opposite of my logic.
It should be the same effect whichever side you do it on! Differential sharpening is more about the contrast between grit sizes rather than where they are, if that makes sense. Good question!
Always interesting to me how in this day and age, something as primitive as sharpening still seems to have some controversy as to exactly how it works and what is the optimal approach.
Amen, brother.
I think that as steels get more complex along with sharpening tools. The more complex simple sharpening gets. Some steels take well too certain grits and even approaches while others you need to be much more careful with during their process. True master sharpener’s know what works for them based on the steels given to them. I have been sharpening for years and only recently have I discovered that no steel and even blade is alike. With anything it’s feel and practice as well as trying our new ways and approaches.
Gabriel L Yeah, that does make sense to me. I guess that at least partly explains it. And there are a lot of things that are understood to some degree to be fair. It's just that when sharpening has been examined to the level of detail capable with a scanning electron microscope and still some of the basic mechanics involved seem elusive and half understood it is interesting, but I guess there are a lot of things like that. Perhaps part of what makes it fun to follow and learn about though.
I suspect that in your test 1000/1000 or 500/500 would have had superior cut speed. However the rougher grit edges would probably have had less longevity
This is a tricky one- depends a lot on the steel and how you're sharpening, but even then we hear a lot of contesting opinions about which grit dulls faster! Maybe a good topic for a future video.
for me i would be 400grit for both side first to create a solid base, them 1000 for one side and 5000 on the other side for general use.😁
I kinda hate the results in this video, my ocd for sure wants 8k x 8k to work the best.
Great video and content as always, Naoto is a beast. Thx to everyone at Knifewear🔪
I enjoyed this video. I wonder if changing the sharpening process slightly would make any difference in the results.
In this video I believe you sharpened both sides with the lower grit then proceeded to polish one side up to a higher grit.
I think this might have the effect of polishing out the toothiness on the cutting edge.
What if you were to sharpen both sides, polish one side on a high grit then go back and make some stropping passes on the low grit side of the blade to re-establish the toothy edge?
The idea is to create large teeth on one side, and smaller ones in between on the other side, and it's the contrast that tends to make for a better cutting experience and lasting edge- I suspect stropping on that lower grit stone again would be a bit self-defeating. Try it out and let us know how it goes!
@@KnifewearKnives Cool, some day I'll have to get a microscope and see what this might actually look like using different techniques
I stopped going above 5k on any knife when I heard a 1st mate on a charter fisher who cut chum to the tune of about 200 fish a day say the finer the grit used the more polished the edge became and the more it rode on top of the fish and didn't bite in. Usually I actually stop at the naniwa green "brick of joy" 2k for 99% of my knives. Maybe you could try doing the winner differential grit sharpening on the tomato with the grit sides reversed to see if that makes a difference. Test a left side low grit right side polish vs a right side low grit and left side polish.
Thanks for your input, that's super.interesting! Well definitely do more comparison in the future!
I'm guessing polished edge is probably slipping on fish scales.
For raw meat I noticed better performance on high polish.
@@thiago.assumpcao I agree but those are sushi or sashimi knives specifically for raw fish meat and not scales. My general purpose knives like my Santoku, Dojo Blue fruit knife and even my Deba do much better with a 2k finish.
@@82delta My general purpose knives I like to keep around 1K but if it's dedicated to meat I prefer high polish.
I don't cut fish much, I wonder if there's a difference.
FREAKEN INSANE TECHNIQUE THANK YOU SENSEI
Happy to hear it!
@@KnifewearKnives I did alternating grinds every other centimeter with 500 // 8000
@@KnifewearKnives alternating 150// 10,000 is super tomato slicer
Great video Naoto. Does the type of steel make a difference? Would a steel like W2 versus something with carbides and more natural bite need different grits to achieve the same effects?
Great question! Each would likely start identical with the same grits, but steels like SLD or W1 age very differently from something like VG10 or R2. More testing and research required... stay tuned!
how is it diffrent from 1k on both sides, thats what i was most intrested in
Looks like we're gonna need to make another video!
@@KnifewearKnives Can you try to reverse the coarse and smooth side in the video? I think it should be the other way around so the pointy sides bites into the food more. From this video I think the coarse grit is beveling the serrations away from the food.
Could you show the deburr in detail? Will it be edge trailing then after the mid grits?
I'll make a note to get some closer shots in the future! And yes, generally the higher we go the more we stick to edge trailing for deburring.
@@KnifewearKnives wouldn't edge trailing create some fold burr, I thought you would use edge leading to cut off the burr completely
What about single right bevel course grit then also mid-grade Grit 🤔
Absolutely!
When this was done did you do this with a 70/30 or 50/50 I feel that would make a large difference
Naoto did 50/50 on each one!
so what's the theory behind differential grit?
Good question! The idea is to combine the smoothness of a finer edge with the bite and longevity of a rougher edge.
@@KnifewearKnives what about chisel grind knives like the deba or yanagiba?
Cutting is really tearing at the microscopic level. Put it under the microscope and you will see the 1000/8000 has micro-serrations of the correct size to "pierce and grab" the tomato skin while the 500/10,000 has teeth that grab the coarser carrot. The 8k/8k just doesn't have teeth large enough to pierce/grab either.
Well said!
Exactly! This is just making an irregular serrated edge. My expectation is that, if you push cut paper, the uneven grit knives would be rougher in feel corresponding to the lowest grit. Polishing the other side makes sharp spots at the high points on the edge but might not remove enough metal to get the gullies unless you really get after it. Serrations are great for grabbing into, and tearing out, smooth surfaces. I still prefer a perfect high grit edge on most kitchen tasks but it does require more maintenance as it is subject to deformation and wear, where a serrated blade dulls mostly from wear and less from apex deformation.
I absolutely hate how my Masakage was sharpened out of the box. The concave in the bevel that is present from the wheel used drives me absolutely up the wall.
Totally understandable, that concave isn't everyone's cup of tea. I find the second time I thinned my Masakage it went away.
@@KnifewearKnives the stainless cladding eats my coarse stone, but really I just need an atoma for thinning.
I sharpen this way too!!! I usually with 250 grit on one side and 6000 the other. Thanks for sharing this!
This is my original method, I did not know there were others doing it. I call it “dual grit” but “differential grit” is a good name too:
ua-cam.com/video/FruwVRSmhWA/v-deo.html
And this is a video where Pete from Cedric& Ada tests a knife with this edge in CPM M4, and it beats his previous record by about 50%:
ua-cam.com/video/jPIJkXfUg5E/v-deo.html
That's awesome! 👏👏
@@KnifewearKnives yeah, your method and testing is so cool too! I would love to see more experiments!
I am testing now to see if it works better on some steels/certain grits/particular abrasives.
#thehomeslice
If my knives are hair whittling sharp using the regular method everyone uses, why would I change to using different grits on different sides? It's just wanking with steel. I'd like to have seen how a 1000/1000 cuts on that tomato.
Originally posted from 'Sharpe like Shibata-San KW video:
Here's the deal...sharpen both edges to your highest grit (mine is #6000), for traditional Japanese steels (AS,A1, A2, S1, S2).
Then, make 10 stropping passes on your outside edge (right side for right handlers), with your 'sharpening stone' grit, (I use #1000), with 3 passes back and forth out of the 10 - (I use pass 6-8). That will give you nearly the sharpest edge currently possible from hand sharpening.
Note: I am am also using an asymmetrical bevel for my blades @ an approx. ratio of 80:20@20'=16':4'' (right handed-bias).
Also note: Shibata-San does this currently with: #8000\#800, which I have not yet tried as I do not own those #'s.