Thread: Complex grinds?

Even on a Western style knife like a gyuto, you can have sections of the blade that are ground flat and parallel, "trapezoid" flat like a wedge or standard flat knife grind, hollow and convex all in a space no more than 2 inches wide.

I do all my cutting with a cheapo cleaver from WallyWorld. Everything from busting up an onion to chopping veggies to cutting through chicken bones. You don't need a range of knives, the cleaver does it all, from finesse work to heavy muscle work.

The same could be said for a cheap disposable plastic razor yet here we are.

Originally Posted by Wayne1963

I do all my cutting with a cheapo cleaver from WallyWorld. Everything from busting up an onion to chopping veggies to cutting through chicken bones. You don't need a range of knives, the cleaver does it all, from finesse work to heavy muscle work.

With the single bevel knives, a lot of them have a tiny secondary bevel on the "flat' side. Also, the convex "transition" can sometimes be the entire blade rode, albeit a VERY shallow convex. Likewise, some double bevel "western" style knives like gyutos, sujihikis and petty can have varying asymmetrical grinds right down at the edge.

Originally Posted by mainaman

The grind looks like this:



pretty interesting to sharpen on stones as well.

That type of grind is used on traditional knives, gyoto and standard double bevel knives use standard symmetric grind.

Originally Posted by JDM61

With the single bevel knives, a lot of them have a tiny secondary bevel on the "flat' side. Also, the convex "transition" can sometimes be the entire blade rode, albeit a VERY shallow convex. Likewise, some double bevel "western" style knives like gyutos, sujihikis and petty can have varying asymmetrical grinds right down at the edge.

Which side is the "flat" side?
From your post I take it you have sharpened knives with that geometry, and have experience with a lot of Japanese kitchen knives?


You must then know that there is no flat side on a traditional knife. Western style knives are symmetrical with exception of Aritsugo gyutos which are intentionally ground asymmetric (back side almost flat). The asymmetry is done post purchase by people that think thin knife cuts better and having no clue how food release works and that a lot of smiths do not know how to grind a proper cutting knife.

Sorry, The "urasuki" side on those knives that actually have the hollow ground into them. As for the "asymmetry" I was talking about stuff like a 60/40. etc primary bevel. The "complex grinds" that I have done are what some would call an "S" grind.

Originally Posted by mainaman

Which side is the "flat" side?
From your post I take it you have sharpened knives with that geometry, and have experience with a lot of Japanese kitchen knives?


You must then know that there is no flat side on a traditional knife. Western style knives are symmetrical with exception of Aritsugo gyutos which are intentionally ground asymmetric (back side almost flat). The asymmetry is done post purchase by people that think thin knife cuts better and having no clue how food release works and that a lot of smiths do not know how to grind a proper cutting knife.

Originally Posted by JDM61

Sorry, The "urasuki" side on those knives that actually have the hollow ground into them.

There should not be micro bevel on the ura side, that defeats the purpose of the grind, same reason we do not put micro bevels on the ura side of Kamisori. The Omote side should have no microbevel as well, but many put one to increase the edge longevity, however the edge fails fast because of lack of cutting technique.

As for the "asymmetry" I was talking about stuff like a 60/40. etc primary bevel.

The knifes usually come 50/50 and most of the time not even sharpened to potential, the smiths in Japan believe that one should put their own edge on their knives to tune them up to one's preferences. As for the asymmetry, I think it is a fad people like to think that that improves cutting, just like people used to think thinned blades are bestter cutters. Ever since Kato was introduced in America, it became apparent that geometry and grind matter a lot more than how thin a blade is. All those are related to food release, and that plays into the cutting action. So IMHO 50/50 is just fine if the knife is made correctly.

True. I am going by what the hardcore looneys do over oaths side of the pond. My understanding is that Shigefusas are not exactly know for being thin whippy "lasers". You say USED to think that thinning behind the edgewas the ticket? When did they stop doing that over here? LOL As for the "factory" edge, in many cases is that an issue of economy in that a maker can't really afford to spend a couple hours putting a highly polished final edge on knives if he expects to make enough to sell? I know that you can pay extra for retailers like JCK to put a "proper" edge on your knife before shipping.

Originally Posted by mainaman

There should be micro bevel on the ura side, that defeats the purpose of the grind, same reason we do not put micro bevels on the ura side of Kamisori. The Omote side should have no microbevel as well, but many put one to increase the edge longevity, however the edge fails fast because of lack of cutting technique.

The knifes usually come 50/50 and most of the time not even sharpened to potential, the smiths in Japan believe that one should put their own edge on their knives to tune them up to one's preferences. As for the asymmetry, I think it is a fad people like to think that that improves cutting, just like people used to think thinned blades are bestter cutters. Ever since Kato was introduced in America, it became apparent that geometry and grind matter a lot more than how thin a blade is. All those are related to food release, and that plays into the cutting action. So IMHO 50/50 is just fine if the knife is made correctly.

Originally Posted by JDM61

True. I am going by what the hardcore looneys do over oaths side of the pond.

what do they do, got any sources to educate us?

My understanding is that Shigefusas are not exactly know for being thin whippy "lasers".

no they are not but they are also not that great cutters without some tinkering.

You say USED to think that thinning behind the edge was the ticket?

yes that was the be all end all trend 3-5 years ago. All of a sudden thin knives such as Suisin INOX Honyaki and Ikkanshi Tadatsuna became very popular because they were "very good" cutters. Then people started realizing that thinness is not the key to better handling, it is grind/geometry. Quite a few people were very surprised how a Kato can out outperform almost anything out there for such thick knife.

LOL As for the "factory" edge, in many cases is that an issue of economy in that a maker can't really afford to spend a couple hours putting a highly polished final edge on knives if he expects to make enough to sell?

No it is just accepted that each chef/cook can put the edge they like on their knife very simple.

I know that you can pay extra for retailers like JCK to put a "proper" edge on your knife before shipping.

Those that do not can't or do not to learn how to sharpen pay for sharpening services it is their choice/right to do w/e they want with their money.

You did not answer my question by the way, what Japanese knives have you personally handled and used, because reading on the forums is not quite the same as actually cutting something and definitely not quite like sharpening a blade, especially a traditional.

My handling of Japanese knives has been quite limited. I currently own two reasonably priced ones, the Hattori form knife suji and one of JCK's "house brand" semi stainless gytuos that were primarily bought to use as patterns. As for picking up stuff on the forums, I have made a number of wa handled western style knives out of W2, 115W8 and my own 1084/15N20 damascus that were sold. Good feedback on all and the one where I got some particularly funny comments was a 270-mm suji using the basic profile of the Hattori but with the S grind that I previously mentioned. It was declared by its food industry pro/ knife nut owner to be a "roast slaying machine" Better lucky than good, right?. So I am a neophyte but not a COMPLETE neophyte.

Originally Posted by mainaman

what do they do, got any sources to educate us?
no they are not but they are also not that great cutters without some tinkering.

yes that was the be all end all trend 3-5 years ago. All of a sudden thin knives such as Suisin INOX Honyaki and Ikkanshi Tadatsuna became very popular because they were "very good" cutters. Then people started realizing that thinness is not the key to better handling, it is grind/geometry. Quite a few people were very surprised how a Kato can out outperform almost anything out there for such thick knife.
No it is just accepted that each chef/cook can put the edge they like on their knife very simple.

Those that do not can't or do not to learn how to sharpen pay for sharpening services it is their choice/right to do w/e they want with their money.

You did not answer my question by the way, what Japanese knives have you personally handled and used, because reading on the forums is not quite the same as actually cutting something and definitely not quite like sharpening a blade, especially a traditional.