Hardness vs sharpness and Honyaki question.

[Kerneldrop]

UPDATE: back to square one.

What is your overall goal? Are you a sharpener looking to get into the hyper-sharp niche?
Are you saying Ginsan can't get sharp, or are you saying Ginsan can get as sharp as Shirogami #1?

[Jeff B]

...why Ginsen is listed again and again as less sharp? Is it heat treatment which doesn’t bring this steel to higher hardness or some other parameter? One way or another am bit hesitant to trust other sellers which doesn’t have similar tables will be offering particular hardness G3 which, yes, will be possible to make as sharp as say white1.

You really seem to have a problem not understanding that hardness DOES NOT increase sharpness! The table you posted shows the White steel rated the same hardness as the G3. Making a steel harder does not make it sharper, the steels metallurgy will determine how sharp it can get. Blue steels are generally heat treated to a higher hardness than White steel yet the White steel will still get sharper because of the purity of the steel and smaller carbides.
Just because G3 may not get quite as sharp as White does not mean that it will not be sharp enough for your needs. Sharpness is also not the only or most important factor in how a knife performs. It's geometry has more influence over it's overall performance than it's peak sharpness.

[taz575]

Hardness effects edge retention and how well it will support a thin edge, but not really sharpness. I prefer the AEB-L and G3 at higher hardnesses because the thin, fine edge won't be as prone to roll over with board contact and the edge holding is better. For your useage, there isn't a lot of heavy board contact and you are slicing soft flesh, so the edge rolling isn't really an issue.

G3 will get plenty sharp for your purposes! White steels and other pure/low alloy carbons have the most potential for a slightly finer edge, but it's really splitting hairs. The grain structure in G3 is slightly larger (due to the alloys and chromium) than carbon steels, but still much finer than most stainless steels and other alloyed steels. G3 is supposed to be very similar to AEB-L and the grain structure of AEB-L and it's edge taking is close to O-1 and 52100 carbon steels.

[jmcnelly85]

Welcome to theoretical sharpness… on a sub micron and molecular level, white steel is sharper than ginsan. Sharpen for years and years and you might be able to spot the difference.

[Kowalski_Boston]

UPDATE: back to square one.

What is your overall goal? Are you a sharpener looking to get into the hyper-sharp niche?

I am a home chef (relatively as for home intensive), but going to sharpen my knives, and yes, vicinity of 50 and below on edge on tester I guess You could call hyper sharp (razors on edge on tester supposedly are at 50). I don’t know, I guess You could say that.

UPDATE: back to square one.

Are you saying Ginsan can't get sharp, or are you saying Ginsan can get as sharp as Shirogami #1?

I saying that ACCORDING TO TWO JAPANESE SELLER’s WEBSITES (links I provided) THEY SAY, Ginsen steel THEY USE, cannot be made as sharp as Carbon steel THEY USE - obviously, right?
Why is that? Not a clue (speculating of possible reasons but really don’t know). I was rather hoping of getting some answers or clues here.

Besides what said, they coin some terms as “Hakuichi” steel, which information about I cannot even find. It supposed to be sharpest steel, which can develop Patina yet it is not same as white or blue. What is it then??? Not a clue.

I know of Nenohi Ginsen Fuguhiki which I do believe is as sharp or better as Carbon.

https://www.toshoknifearts.com/en-us/co ... d204-ia240

That’s what Nenohi claims in his video (Wall Street Journal production):

https://youtu.be/UotpApc8hDg?si=CNvwcmDWTptxrmTK

He says that belief among Japanese chefs is - carbon steel is sharper than stainless, belief he tries to change. He also says that making knife unless it matches or exceeds in performance makes no sense. Hence assumption is, HIS stainless Ginsen IS as sharp or better than carbon (website also mentions sharpening it is more difficult - which is consistent with what I absorbed from this thread - which is: yes, Ginsen CAN be as sharp as carbon, but to get there it might be harder to sharpen it, requiring things as successive progression on diamond plates). That’s what my expectation of getting “G3 in 62-ish” range on Rockwell is.

Problem with Nenohi is price. I’m not sure I want to pay $650 plus shipping.

...why Ginsen is listed again and again as less sharp? Is it heat treatment which doesn’t bring this steel to higher hardness or some other parameter? One way or another am bit hesitant to trust other sellers which doesn’t have similar tables will be offering particular hardness G3 which, yes, will be possible to make as sharp as say white1.

Just because G3 may not get quite as sharp as White does not mean that it will not be sharp enough for your needs. Sharpness is also not the only or most important factor in how a knife performs. It's geometry has more influence over it's overall performance than it's peak sharpness.

Don’t understand this statement at all. Isn’t “geometry” by which I assume you mean “angle of apex” THE biggest factor which determines “sharpness”. I understand arguments about micro abrasions and “other factors” which in general terms affect performance, …BUT on edge polished on ultra high grids, with 8k possibly 16, 32, 64 (not sure how high I decide to go. High mirror on entire knife if possible, but on edge it definitely will be as high mirror as I can get), Carbon or G3, in my particular case will those “other factors” mater at all? I’m going to make edge ultra polished and as acute as I dare to go. Hence for me factors which are important is possibly smallest grain (would love to get AEL - can’t find it), material which can hold possibly most acute edge (AND still be practical to use on soft textures), and thinnest possible apex (again which will not crumble or chip in soft textures).

With brittle edges concern not only is board contact, but also twisting edge when cutting through meat. Problem is, cutting particularly for Nigiri with single bevel DOES REQUIRE twisting. While for sashimi cut is straight, Nigiri requires going at a curve. For this reason I expecting finding exact most acute possible and practical angle challenging to determine. And for this reason, again, relying on expertise of experts to do Honbazuke, rather than own try and error would be definitely preferable. As easy to guess, going back and forth between different edge angles, convex and zero bevels, might result in grinding knife to nothing before I know it, on top, likely on hard material which might be labor intensive.

Changing bevel angle, where bevel is not a flat surface (it usually have convex out of the store plus looking from another perspective, angle of bevel changes throughout length of the blade, as spine thins towards the end) WHILE not screwing Shinogi line (holding it parallel to edge) is quite challenging task.

I heard in YouTube video argumentation: if you say pay $200-300 for a knife, do you really want to spend $400 for stones to sharpen it? In my case answer is: YES! I get best possible knife I can afford. But to hold it peak sharp, I definitely will invest in tools to do it (otherwise getting good knife makes no sense at all). Not talking natural stones, but definitely quality diamond/wet stones. Which? Will decide once I get the knife and know what is its hardness and what I need.

Fuguhiki was specifically designed for cutting puffer fish, which is cut ultra thin (such cut is called Usuzukuri in Japanese), where need for precise very sharp tool was recognized. It’s not only about edge, but also considerably thinner spine (geometry) for this particular reason. It is tool which is more nimble than Yanagiba and intended to be very sharp. Firm textures are easier to cut. Soft harder (IF you talk ultra thin AND clean), and puffer fish IS NOT the softest. Fuguhiki are made not only for puffer fish BUT ALSO specifically for Usuzukuri. Atlantic Sea Scallops is softer, while some Jelly fish are even softer. Try cutting very soft Jelly fish to say 0.1 - 0.25mm thickness. I can guarantee you unless you use razor (literally not figuratively), you will not be able to make any cut at all (unless tearing and deforming you call cutting), not to mention “clean cut” to sushi/sashimi standard. Semi frozen/cold soft textures are easier to cut BUT they heave tendency to tear BECAUSE they are semi frozen/cold. Which gives optimal slightly cold, which, unfortunately, are still very soft.

I would prefer stainless over carbon (if it will be ultra sharp) because of aesthetics (no Patina) and pain in keeping rust free, where some visually unpleasant Patina on possibly high mirror AND possibly hard material sounds just as nightmare scenario.

Stainless is pretty, stays pretty, is worry free and requires way less maintenance, with exception of eventually restoring mirror (where any steel, and hard in particular task will be hard/gargantuan).

...why Ginsen is listed again and again as less sharp? Is it heat treatment which doesn’t bring this steel to higher hardness or some other parameter? One way or another am bit hesitant to trust other sellers which doesn’t have similar tables will be offering particular hardness G3 which, yes, will be possible to make as sharp as say white1.

You really seem to have a problem not understanding that hardness DOES NOT increase sharpness!

My language is over generalizing, as pointed, lacking nuance and subtlety. Im not talking general metallurgy science but my particular case. I still not fully grasp all what is said, but guessing you are probably right in general terms. In my particular case: harder steel can hold more acute edge angle while remaining practical to use. Right? More acute angle on other hands (beside fine grain structure) is THE biggest factor determining sharpness. That what is hidden beneath knife’s“geometry” term. Right? I’m buying Fuguhiki. All Fuguhikis have same blade geometry (eventually varying in length, and style as Kagata, Kieitzuke etc) no matter which steel.

For your useage, there isn't a lot of heavy board contact and you are slicing soft flesh, so the edge rolling isn't really an issue.

G3 will get plenty sharp for your purposes! White steels and other pure/low alloy carbons have the most potential for a slightly finer edge, but it's really splitting hairs. The grain structure in G3 is slightly larger (due to the alloys and chromium) than carbon steels, but still much finer than most stainless steels and other alloyed steels.

I sort of replied to many aspect of this reply earlier in this reply so won’t repeat myself.
Just to make couple points. I definitely won’t get carbon mono-steel (way too much pain), hence other option would be Kasumitogi, probably Shirogami 2 Hagane, WHICH, according to some other sources (unfortunately) is slightly less sharp supposedly due to carbon lost in Hagane due to cladding process. Which I guess brings this “hair splitting” difference even closer to G3. Problem is, as you can see from previous post, options are: G3 seems to have more than hair splitting difference from carbon from reputable sellers (three stars versus five), unknown on most, and minimal if you willing (and I’m not ready) to pay for top craftsman (Nenohi).
I don’t know are those Japanese sellers post incorrect information? They seem to be high in experience and their craft. That would be definitely against their interest. I exchanged e-mails with Makato Tadokoro wife about their return policies on defective knife. She replied, if it get damaged in shipment they cover replacement and shipping costs, and as to sending knife with some defects (which I know do happen from other sellers, as loose or slightly incorrectly installed handle, bent, warp, even not straight Shinogi line - from some Sakai Takayuki), she replied flatly: we very carefully inspect all our knives. Rest assured we do not send any defective knives.

[Kowalski_Boston]

I think possibly theoretical/scientific understanding of “sharpness” might differ from practical. “Sharp” in sushi/sashimi world does not mean same “sharp” used anywhere else. I have collection of cheap stainless steels which I can made “very sharp” with my stones. Couple of them will cut your finger if you try test their sharpness by putting gently finger on their edge, … yet,.. when trying to cut say scallops ultra thin, I cannot do it all. Using Home Depot razors which as you would expect doesn’t do it either. Too short blade, not stiff enough.
Don’t really know just making guesses.

[taz575]

So you want high end stainless steel with ultra sharpness, but want to pay mid level carbon prices ($200-300) for it? Then invest $400 in stones to sharpen it?

And then spend hours refining the blade on the stones?

Instead of the Nenohi for $650?

[Kowalski_Boston]

So you want high end stainless steel with ultra sharpness, but want to pay mid level carbon prices ($200-300) for it? Then invest $400 in stones to sharpen it?

And then spend hours refining the blade on the stones?

Instead of the Nenohi for $650?

Whether I buy Nenohi or anything else, I still will need good stones. It’s not like if you buy great knife it’s going to sharpen itself. So going to buy stones, then spend $200-450 for knife. $200-300 was only example.

[Kerneldrop]

I'm getting mixed signals....do you sharpen yet or do you want to learn sharpening?

I'm not going to change your mind...but i like to keep things simple. Shibata and Myojin, two of the best sharpeners in Japan, both have G3 lines with their names on them. That should tell you all you need to know about G3 and it's sharpness ability.

A hyper-sharpener on FB sharpened a Japanese knife to a high single digit BESS using cheap King stones.
Another hyper-sharpener I talk with takes $1 dollar store Santokus and by the time he's done sharpening he's horizontally slicing carrots without the carrots moving on the board. He sends me videos...it's real. Those knives probably don't even have a heat treat.

Everyone that posted on this thread has extensive high-level sharpening... it's all about the skill, and really it's about crafting an edge.

Eventually you'll need to quit researching and get an action plan: get a Hado or Isamitsu in shirogami #1 and get after it. Either option is produced by master smiths and master sharpeners that specialize in that steel. You'll theoretically have the sharpest knives on the planet. Nakagawa does Shirogami #1, too.

[polytope]

Besides what said, they coin some terms as “Hakuichi” steel, which information about I cannot even find. It supposed to be sharpest steel, which can develop Patina yet it is not same as white or blue. What is it then??? Not a clue.

"Shiro" and "haku" are both white. "ichi" is 1. Your (and I guess their) automated translator seems to randomly prefer one vs the other in your image.

From top to bottom the image is "shiro ni ko" white 2 steel, "gin san ko" gold 3 steel, "V Gold 10 something" obviously VG10, "shiro ichi ko" white 1 steel, "ao ni ko" blue 2 steel, "ao ichi ko" blue 1 steel.

Edit: also, nobody's saying this seller's picture is wrong (at least, not that I've seen, I'm just skimming the thread). They're saying you're interpreting the information in it incorrectly. Steels are tradeoffs and the image communicates roughly what they are, but there isn't a scale on it saying precisely what "one star's worth of sharpness" means.

[jmcnelly85]

What stones do you have? I don’t believe ginsan needs special “top of the line “ stones as long as they are quality you should be fine with any reputable stones.

[Jeff B]

...harder steel can hold more acute edge angle while remaining practical to use. Right?

Wrong. A very hard carbon will be more likely to chip at a very acute angle than softer G3. Higher hardness tends to make carbon steels more brittle, that is the trade off. Again, how acute you can take an angle at a specific hardness varies by steel and depends again on metallurgy. Ginsan 3 is a very tough steel, almost as tough as AEB-L, both are tougher than carbons.

[salemj]

This is a very confusing thread for me.

I wrote a long post, but I erased it because I think bottom line is that I think the FEEL of different steel edges is usually pretty obvious. Some definitely feel like they can take more refined edges than others that could work better on some foods, but these feelings are WELL below their theoretical limits. I think you should consider this. To be as honest and earnest as possible, if I had to cut items at under 1mm thickness and had issues about stainless versus carbon, I would be far more concerned about comparing different heat treatments of Ginsan to R2 to ZDP-189 to SKD to SLD than I would worry about the theoretical differences between Ginsan and White 1. To me, all of those stainless options feel quite different. It is less about their ultimately sharpness, and far more about how they feel and perform at different levels of refinement that they are all very capable of and that I also think are high enough to achieve the types of cuts you are after.

Also: ignore the hype and websites. The WSJ video you cite is mostly ridiculous marketing (which is not to say the knives are bad, but it is to say that the idea of a 20,000 knife - the cost of which is mostly related to an exotic handle and finishing and not some upgrade from their typical products - is not an accurate representation of their product, nor is any suggestion that their knives are somehow preferred in any absolute sense to the dozens of other options for high-end chefs in Japan), and any Japanese cite that is talking about the "sharpness" of steel is not geared toward the theoretical questions you are posing. Trust me when I say that real, professional claims about the capabilities of metal are always context-dependent, both in terms of the specifics of the steel treatment and in terms of the testing of the edge. A blanket claim that one steel is capable of a sharper edge than another is about as reliable as any folding knife website that says its steel is the "best" steel for the magic combination of sharpness, edge retention, and practicality in the field.

I hate to write stuff like that, but I think my point is simple. It sounds like you know some chefs and how they use their knives. Why don't you talk to them? My guess is that their actual priorities are a bit different than your current ones.

[Kowalski_Boston]

I'm getting mixed signals....do you sharpen yet or do you want to learn sharpening?

Im sharpening already. Close to zip of practical experience (just started maybe month ago), tons and tons of theory though. I think I spend well over 100+ hours on YouTube, watching 20+ YouTubers. It’s all cheap stainless double bevel steels for now, good for practice and experimenting (with higher angles, fixing chips and broken tips and everything really in general) but also using them for cutting so just need to sharpen them. Bought myself 30x 60x 90x magnification loupe (really helpful) to be able to see what happen with apax, burr and edge. Don’t owe single bevel or any respectable knife so far.

I’m replying quickly, as once my day off ends it will be difficult to do it. Your post contains lots of unfamiliar words I will have to Google and translate to understand, then chew through what You said. If you trying to persuade me there are great G3s out there, no need, I’m sold already. Problem is finding good Fuguhiki. There are significantly less of them than Yanagi. In any case thanks for reply.

Besides what said, they coin some terms as “Hakuichi” steel, which information about I cannot even find. It supposed to be sharpest steel, which can develop Patina yet it is not same as white or blue. What is it then??? Not a clue.

"Shiro" and "haku" are both white. "ichi" is 1. Your (and I guess their) automated translator seems to randomly prefer one vs the other in your image.

From top to bottom the image is "shiro ni ko" white 2 steel, "gin san ko" gold 3 steel, "V Gold 10 something" obviously VG10, "shiro ichi ko" white 1 steel, "ao ni ko" blue 2 steel, "ao ichi ko" blue 1 steel.

Edit: also, nobody's saying this seller's picture is wrong (at least, not that I've seen, I'm just skimming the thread). They're saying you're interpreting the information in it incorrectly. Steels are tradeoffs and the image communicates roughly what they are, but there isn't a scale on it saying precisely what "one star's worth of sharpness" means.

Thanks for help with translation. To be honest vibes I sense from replies is, as if I was trying to say all everyone is saying is not true and Ginsen cannot be made sharper than carbon - which is just NOT what I say at all. I DO believe, especially after awesome taz575 pictured reply, G3 CAN BE as sharp.

What stones do you have? I don’t believe ginsan needs special “top of the line “ stones as long as they are quality you should be fine with any reputable stones.

I listed all stones, strops and emulsion I have so far on previous page of this tread.

...harder steel can hold more acute edge angle while remaining practical to use. Right?

A very hard carbon will be more likely to chip at a very acute angle than softer G3. Higher hardness tends to make carbon steels more brittle, that is the trade off.

That is well understood. Still that would be more of a trade off (not to mention simplification as yes I do understand property, grains of steels may matter even more) rather than completely incorrect understanding. Right?

This is a very confusing thread for me.
(…)
Also: ignore the hype and websites. The WSJ video you cite is mostly ridiculous marketing
(…)
It sounds like you know some chefs and how they use their knives. Why don't you talk to them? My guess is that their actual priorities are a bit different than your current ones.

Well thanks for WSJ warning. Noobs like me lacking solid knowledge are easy to fool.

I don’t know any chefs in real life, even I watched tens if not hundred of them on YouTube. Would I know one I would murder him to let me cut something with his Yanagi. Either he would let me cut or I would end up with restraining order.

Problem, when buying Japanese knife is, when you live in Boston, everything about those knife is theoretical. You can watch pictures on Internet, read about them, watch them on YouTube, but even holding one in hand is problematic, not to mention what you really need is “test drive”, cutting something with it, getting good sense of different steels, styles and so forth.

In entire Boston I was able to find but one store which has three Yanagibas. They were all Masamoto Sohonten (stamped ones) Kasumitogi Shirogami-2 Hagane, with Kasumi finish, 62 HRC, three different lengths. Had to picture and translate paper inside the box to figure what exactly they were. Store description said nothing besides Masamoto.
It was the only time I was able to hold sushi slicer in my hand, get some sense of it, touch the blade, look it under phone microscope. I knew since beginning I want Fuguhiki not Yanagi, so knew I will not buy it, even so was happy I had a chance feel it in my hand. Get any sense of it at all.

Also, taking occasion correction. Previously posted Nenohi is Yanagiba not Fuguhiki. The only similar existing Nenohi Fuguhiki is in Australia and out of stocks. Three other Nenohi Fuguhiki in Japanese location not selling to US are Honyakis in $2,000+ range.

Well, again, thank You everybody for replies. It will again take me some time to chew through all information.

[Kowalski_Boston]

You guys are on so much different level than me. I sensing some academic metallurgy background. It really takes me long time to sometimes fully understand what you even trying to say. Some of those posts I read like 3-4 times and still fully not grasping everything in them.

[Kowalski_Boston]

Hardness effects edge retention and how well it will support a thin edge, but not really sharpness. I prefer the AEB-L and G3 at higher hardnesses because the thin, fine edge won't be as prone to roll over with board contact and the edge holding is better. For your useage, there isn't a lot of heavy board contact and you are slicing soft flesh, so the edge rolling isn't really an issue.

Thanks for the reply. Reading again through replies and realizing I missing some points. First even I mentioned not touching board at all, it was more in terms of willingness to make sacrifices in order to get ultra sharpness I need rather than preferred course of action. Little contact will do one way or another, no contact if it gives me sharper edge (by putting more acute edge and making it more brittle). In context of understanding this are you still judging “edge rolling isn’t the issue”?

Second question is hardness vs sharpness vs edge retention. You are the second person that states this, yet from previous replies I drawn different understanding - just clear my misunderstanding.
My understanding is: higher hardness will allow finer edge which it will be able to hold. Finer edge translates directly to higher sharpness. Why then higher hardness affects edge retention but not sharpness? I remember some YouTube video, Burrfection if I remember correctly. Don’t remember exact subject (edge retention- measures of sharpness with edge-on-tester for different knives after cutting through some medium - ??? Best guess) by bit pseudo scientific methods (by his own admission) which home set up allows. Anyway from watching video it became clear, the parameter which is the most important for sharpness in general, in all knives was angle of the edge. Seems “geometry” everybody refers to. So why ability of achieving this finer geometry doesn’t translate directly to sharpness but to retention. What am I missing?

G3 will get plenty sharp for your purposes! White steels and other pure/low alloy carbons have the most potential for a slightly finer edge, but it's really splitting hairs. The grain structure in G3 is slightly larger (due to the alloys and chromium) than carbon steels, but still much finer than most stainless steels and other alloyed steels. G3 is supposed to be very similar to AEB-L and the grain structure of AEB-L and it's edge taking is close to O-1 and 52100 carbon steels.

It seems as you guys (perhaps trying to be polite) instead of telling things directly - trying to hint me?
Am I misreading stars results? Should just ignore them, go for it and buy it?
Must say, for Honbazuke service alone they offer, mirror option (at not terribly high price ¥6.820), I would definitely happily go for them if I wasn’t concerned knife will not be possible to get ultra sharp.

Things which I weight in my mind is, reading all this, just from Home Depot razor experience, razor (which I assume is 50 on edge on tester) is about sharpness I need. Won’t split hairs if it is say 70, anyway that’s very, very sharp. When watching YouTube sharpeners I know people getting those numbers: 60, 40, 28 on not Honyaki knives, where indeed older fellow which recently bought himself microscope (not a bad idea btw) to watch his apax claims he recently achieved “awesome result” of,.. 140…. (I’d say he probably has room to improve with stropping). Now when you say “hair splitting” I wonder is “hair splitting” extra 10, 20 or perhaps 70, which yeah, might not be much, possibly even detectable when cutting Tuna for sashimi, BUT, might matter if you try something really, really soft, and you want ultra thin and very cleanly made cut.

Things I’m sensing from replies from this thread, Kasumitogi with Shirogami core is something nobody in this thread recommends (which by the way, by lower price alone I suspecting is really not up to sharpness and value in general).

Guessing correctly?

[taz575]

With a chef knife, like a gyuto, it is usually contacting and gliding across the board with every stroke and sometimes with a good bit of force. Chefs are using them hard and fast often, rocking and gliding on the board. Too hard, it can lead to chipping, too soft (mid to high 50's usually), the edge will eventually roll over so the apex isn't lined up with the rest of the blade. Typical western type knives (henckels, wustoff, victorinox, etc) often use honing steels to re align the edge since it rolls over often. When it rolls, the apex is still somewhat sharp, but mis aligned. 59-60 HRC is typically where the rolling issues usually tend to stop, so if the G3 is that hardness or above, it should be fine!

With the cutting you are doing, the edge retention is less of an issue. Board contact will wear the edge a bit, but with slicing, there is less hard board contact, so the edge retention will usually be better in a Fuguhiki than a gyuto/chefs knife because the useage is different. Some low alloy steels, like Carbon steels, G3, AEB-L, etc, use a higher hardness to get better wear resistance and edge retention to make up for the lack of carbides/alloys in the steel, which increase grain size. Mowing down onions, cabbage, cutting lots of proteins quickly and having a lot of hard board contact is a different useage than a precise, controlled more gently slicing technique you would use in your situation. Your useage would put less wear and tear on the edge, so a higher hardness for better edge retention may not be needed.

If the steel is too hard, it can chip easier with hard contact, but that hardness depends on the steel itself and it's toughness. So something like Magnacut, it has good toughness at 64 HRC, but another steel, like S90V, will be very brittle at that hardness. Thinner kitchen knife edges make this different more obvious than a thicker outdoors type knife and there is less steel behind the edge to support it. No kitchen knife should chip when cutting through cooked or uncooked proteins and the soft tissue shouldn't be taxing on an edge like cutting through harder root veggies skins and stuff.

Geometry refers to the main blade grind itself as well as the edge; it is inclusive. With the CATRA testing you are looking at, lower edge angles means higher wear resistance and easier cutting, but it may not be practical in real world scenarios. A thicker edge will feel duller and have more resistance when cutting through items than a thinner edge, even though they are the same apex grit/sharpness. A thinner blade will let you gain better performance with the same edge and better product penetration. Geometry is about how the blade is ground and how the steel supports the thin edge and if the steel has sufficient toughness/grain structure to support the edge.

You can sharpen/polish mild or soft steel to get wickedly sharp, but in use, it won't last at all. That is why most don't polish the softer kitchen knife edges; it will roll quickly and need to be redone and the softer steel does better with a toothier, low grit edge and cuts longer to help offset the lower hardness to get better edge retention/performance from the softer steel. People who do a lot of butchery actually prefer a coarser/toothier edge since it "bites" the proteins better. When I used to butcher deer, I would often use a 1000-2000 grit stone for sharpening and strop on bare rough side leather since it bit into the fat and protein better instead of possibly sliding off from the more polished edge if the edge wasn't fully as sharp. I wanted something I could touch up quickly and not spend a lot of time super polishing the edge. With the softer proteins, I don't know if a toothier edge would be beneficial or not; I would think it wouldn't have the same texture as a polished edge/surface that you are trying to create! So in your case, you probably want a very polished edge!

You can get super hard steel and get a wickedly sharp edge, but it will often take longer, which means there is more time for user error to come into play, so most struggle with getting the same sharpness. With Super Hard Steels, the steel itself may be too brittle in real world use. If the steel has large carbides present in the steel, unless your sharpening stones can abrade that carbide, sharpening may "rip" out the carbides in the steel, leaving a toothier/jagged feeling edge. Something like S90V has large vanadium carbides that are difficult to abrade due to their crazy high hardness well above the rest of the knife steel, so diamonds work well, but regular stones may not be able to sharpen the actual carbides, making the edge feel dull. With G3, AEB-L and simple carbon steels, the carbides are not an issue because they are smaller and can sharpen with traditional stones easily. Vanadium carbides are a royal PITA to sharpen compared to Chromium carbides!!!!

So in short; get some stones, get a decent Japanese kitchen knife (gyuto, kiritsuke, something basic) and learn to sharpen it. Learn to deburr and make sure you are reaching the apex. Get some strops and compounds and use those to refine your edge. Strops are a bit easier than the super high grit (16K+) stones in my experience and you can get sub micron compounds easily. Watching youtube videos and doing research is all well and good, but you need to separate the theoretical and practical and see how things perform in your situation. Watching straight razor shavers talk about stuff is a bit different than what you are doing and is a whole different ball of wax since the edges flex and are stupidly thin that most likely won't work in your situation! Watching people sharpening chef knives is different than your application.

If you have a BESS tester, great, but I wouldn't get hung up on other peoples numbers unless it is someone who specializes in that you do that is looking at BESS numbers. I also wouldn't assume that a Home Depot razor blade is a 50 BESS blade, either!

For stones, you don't need anything fancy for G3. The sharpal is good for initial bevel setting and starting the bevel, but I would go to the 1K you have, then get something in the 3-5K range, then see if you want to go to strops or finer stones from there. 1K stone, then strops and compounds doesn't really show how the edge can be since it will take a TON of 1 micron stropping from a 1K stone! I have a Rika 5K stone, others like one of the 6K that CKTG sells (can't remember the name currently, it may be the arayshima 6K??). I used my Bester 1200 and Rika 5K for many years on all different steels and only went to diamonds after using S90V and CPM20CV a lot in my custom knives that have lots of Vanadium carbides. The other stones still worked, but were slow and had more opportunity for messing up the angle and rounding the edge.

I wouldn't have an issue with the Marushin Fugubiki's since they know what is needed from those blades. I would see if they tell you the hardness, or if they can make it slightly harder (ie from 60 to 61 or 62) if it really concerns you since they do them one at a time according to their website. I wouldn't have an issue going with their G3 (Silver 3) blade at all! VG-10 is often run at 60-61, but many find it harder to sharpen because of the carbides and it tends to hold onto a burr more than G3 and simple carbon steels, so I wonder if the translation of "harder" should be "more difficult"?

[Kowalski_Boston]

With a chef knife, like a gyuto, it is usually contacting and gliding across the board with every stroke and sometimes with a good bit of force. Chefs are using them hard and fast often, rocking and gliding on the board. Too hard, it can lead to chipping, too soft (mid to high 50's usually), the edge will eventually roll over so the apex isn't lined up with the rest of the blade. Typical western type knives (henckels, wustoff, victorinox, etc) often use honing steels to re align the edge since it rolls over often. When it rolls, the apex is still somewhat sharp, but mis aligned. 59-60 HRC is typically where the rolling issues usually tend to stop, so if the G3 is that hardness or above, it should be fine!

With the cutting you are doing, the edge retention is less of an issue. Board contact will wear the edge a bit, but with slicing, there is less hard board contact, so the edge retention will usually be better in a Fuguhiki than a gyuto/chefs knife because the useage is different. Some low alloy steels, like Carbon steels, G3, AEB-L, etc, use a higher hardness to get better wear resistance and edge retention to make up for the lack of carbides/alloys in the steel, which increase grain size. Mowing down onions, cabbage, cutting lots of proteins quickly and having a lot of hard board contact is a different useage than a precise, controlled more gently slicing technique you would use in your situation. Your useage would put less wear and tear on the edge, so a higher hardness for better edge retention may not be needed.

If the steel is too hard, it can chip easier with hard contact, but that hardness depends on the steel itself and it's toughness. So something like Magnacut, it has good toughness at 64 HRC, but another steel, like S90V, will be very brittle at that hardness. Thinner kitchen knife edges make this different more obvious than a thicker outdoors type knife and there is less steel behind the edge to support it. No kitchen knife should chip when cutting through cooked or uncooked proteins and the soft tissue shouldn't be taxing on an edge like cutting through harder root veggies skins and stuff.

Geometry refers to the main blade grind itself as well as the edge; it is inclusive. With the CATRA testing you are looking at, lower edge angles means higher wear resistance and easier cutting, but it may not be practical in real world scenarios. A thicker edge will feel duller and have more resistance when cutting through items than a thinner edge, even though they are the same apex grit/sharpness. A thinner blade will let you gain better performance with the same edge and better product penetration. Geometry is about how the blade is ground and how the steel supports the thin edge and if the steel has sufficient toughness/grain structure to support the edge.

You can sharpen/polish mild or soft steel to get wickedly sharp, but in use, it won't last at all. That is why most don't polish the softer kitchen knife edges; it will roll quickly and need to be redone and the softer steel does better with a toothier, low grit edge and cuts longer to help offset the lower hardness to get better edge retention/performance from the softer steel. People who do a lot of butchery actually prefer a coarser/toothier edge since it "bites" the proteins better. When I used to butcher deer, I would often use a 1000-2000 grit stone for sharpening and strop on bare rough side leather since it bit into the fat and protein better instead of possibly sliding off from the more polished edge if the edge wasn't fully as sharp. I wanted something I could touch up quickly and not spend a lot of time super polishing the edge. With the softer proteins, I don't know if a toothier edge would be beneficial or not; I would think it wouldn't have the same texture as a polished edge/surface that you are trying to create! So in your case, you probably want a very polished edge!

You can get super hard steel and get a wickedly sharp edge, but it will often take longer, which means there is more time for user error to come into play, so most struggle with getting the same sharpness. With Super Hard Steels, the steel itself may be too brittle in real world use. If the steel has large carbides present in the steel, unless your sharpening stones can abrade that carbide, sharpening may "rip" out the carbides in the steel, leaving a toothier/jagged feeling edge. Something like S90V has large vanadium carbides that are difficult to abrade due to their crazy high hardness well above the rest of the knife steel, so diamonds work well, but regular stones may not be able to sharpen the actual carbides, making the edge feel dull. With G3, AEB-L and simple carbon steels, the carbides are not an issue because they are smaller and can sharpen with traditional stones easily. Vanadium carbides are a royal PITA to sharpen compared to Chromium carbides!!!!

So in short; get some stones, get a decent Japanese kitchen knife (gyuto, kiritsuke, something basic) and learn to sharpen it. Learn to deburr and make sure you are reaching the apex. Get some strops and compounds and use those to refine your edge. Strops are a bit easier than the super high grit (16K+) stones in my experience and you can get sub micron compounds easily. Watching youtube videos and doing research is all well and good, but you need to separate the theoretical and practical and see how things perform in your situation. Watching straight razor shavers talk about stuff is a bit different than what you are doing and is a whole different ball of wax since the edges flex and are stupidly thin that most likely won't work in your situation! Watching people sharpening chef knives is different than your application.

If you have a BESS tester, great, but I wouldn't get hung up on other peoples numbers unless it is someone who specializes in that you do that is looking at BESS numbers. I also wouldn't assume that a Home Depot razor blade is a 50 BESS blade, either!

For stones, you don't need anything fancy for G3. The sharpal is good for initial bevel setting and starting the bevel, but I would go to the 1K you have, then get something in the 3-5K range, then see if you want to go to strops or finer stones from there. 1K stone, then strops and compounds doesn't really show how the edge can be since it will take a TON of 1 micron stropping from a 1K stone! I have a Rika 5K stone, others like one of the 6K that CKTG sells (can't remember the name currently, it may be the arayshima 6K??). I used my Bester 1200 and Rika 5K for many years on all different steels and only went to diamonds after using S90V and CPM20CV a lot in my custom knives that have lots of Vanadium carbides. The other stones still worked, but were slow and had more opportunity for messing up the angle and rounding the edge.

I wouldn't have an issue with the Marushin Fugubiki's since they know what is needed from those blades. I would see if they tell you the hardness, or if they can make it slightly harder (ie from 60 to 61 or 62) if it really concerns you since they do them one at a time according to their website. I wouldn't have an issue going with their G3 (Silver 3) blade at all! VG-10 is often run at 60-61, but many find it harder to sharpen because of the carbides and it tends to hold onto a burr more than G3 and simple carbon steels, so I wonder if the translation of "harder" should be "more difficult"?

Per usual I cannot understand every sentence from your reply (LOL). Anyway thank You very much for very long answer. I have contacted Marushin. G3 is at 60-61 HRC, they said bumping hardness is not possible (despite indeed what they claim about“listening and adjusting to customers needs”).
After much thinking, I think I sleep on decision till maybe Monday, then probably will go for it and buy it.
Once order is made, it cannot be cancelled and they give 3 day window for returning if it’s found defective. Wait time is about 60 days (looks like they have to make a new knife for me from a scratch). Total price including shipping ¥52.120 (~$360 at current currency exchange rate), which considering mirror polish, rosewood handle, buffalo horn and Honbazuke I still considering a steal. I guess Custom fee might add extra, I hoping it to be in $20-30 range - estimate based on reaserch done for knife coming from UK, (which I have not bought - assuming it should be about same).

“Honbazuke” I think normally means just sharpening. From Marushin e-mail description however, even not said specifically, I presuming (perhaps wrongly) it to be increased to more acute angle of the edge - quote:

“By performing Honbazuke, (本刃付)the blade becomes sharper. Since the edge becomes extremely thin, delicate handling is required. 
Japanese chefs understand this very well. 
When Honbazuke (本刃付)is applied, the sharpness increases, but please be careful as the edge may chip when cutting hard ingredients.”

Going to request them not to put micro bevel on the edge (well, I mean unless they insist is strongly recommended or something). Expecting knife might bend on its own (hopefully it won’t warp) within time frame of up to 6 months from material internal stresses left during making.

I don’t owe BESS. I only see what other sharpeners measure sometimes with theirs BESS on their YouTube videos.

For stones, since it’s softer steel than originally thought, I am thinking of getting either Aroshiyama or Niniwa Professional at maybe 5k and 10k (intermediate stone to make things easier, faster). High polish of edge would be strops. To my understanding universally loved from always was Niniwa Pro (formerly known as Chocera). Many of those videos are however 3-6 year old, and in newer (don’t remember which exactly now) I think I’ve heard couple times claim Aroshiyama to be better than Naniwa. I also understand that Naniwa are higher grit than stated, so for 5,10k would probably get correspondingly 3,8k - for Naniwa.

When asking for advice on steel in general terms there are two contradicting recommendations. Sushi/sashimi people tend to recommend carbon, tending to trying to persuade living with patina is no terrible. Sharpeners/knife makers/academic (?) community (which I guess is this forum here), tend recommending small grain stainless (as obvious from this thread). That said, Usuzukuri is not terribly common thing among sushi/sashimi people, hence not terribly lot of understanding in regard to its specific needs. I’m into Usuzukuri because of budget reasons. I tend to use seafood which is quite blant in taste and often gummy in texture (but relatively cheaper: squid, cuttlefish, octopus, jellyfish etc etc). Cutting it ultra thin and adding something on top is one of methods of improving taste, making easier to chew, having good presentation, making it overall way, way better. Not terribly lot of people doing same thing.
I expecting professional sharpeners to have higher expertise on steel potentials, where again I asking myself question, how much understanding I finding in particular for Usuzukuri needs. Only praying, I have explained sufficiently, it was understood, all was taken into account and knife sharpness will be achievable to meet needed level.

For methods of sharpening Yanagiba/Fuguhiki after watching something like 20+ YouTubers I think I liked most Naoto from Knifeware. Absorbed many very useful information from his videos. One thing, if I remember correctly - possibly confusing things (will go over all those videos again before sharpening), he seems to sharpen Ura at the 45° angle on the stone, while many sharpeners insist 90° perpendicular angle is very important (to sharpen corresponding opposite points of Ura oshi at the same length of the blade at the same rate, not to mention angle would probably leave blind spot on spine at the heel). Anyway will watch videos again, go very slowly, try to remember of all possible mistake precautions, examine progress under loupe frequently. Pretty much already trying to learn to feel things on the stone. New steel assuming to be new experience, while single bevel (even theory researched thoroughly) new thing I start doing in practice.

Thank You everybody for your help!!!
As always comments and advices welcomed.

[taz575]

60-61 Rockwell is fine for that steel! It should work very well for you!

[jakasspeech49]

Two identical steels can be treated to an identical Rockwell hardness; however, they may not have the same heat treatment. Two bread loaves with identical ingredients can have identical crust, but it doesn’t mean they’ll taste the same. tu Rockwell hardness is only one small part of the equation. Its importance is overstated because it’s an easy number to point to, but it doesn’t necessarily mean much.

That's a great analogy!