New stainless king of the hill?

Yeah, pretty much. The Kohetsu HAP40 has surpassed (IMHO) the Ikeda (SRS-15) as far as edge retention is concerned. Both get equally sharp but the Koehtsu holds it's edge longer (significantly, but not mind-blowingly so). Seeing as they are around the same price (I think the Kohetsu is a little cheaper actually) I have to now recommend the Kohetsu over the Ikeda. If anyone knows of another knife out these that can hang with the HAP40, I'm all ears... cause I haven't found one... and that includes R2, SRS-15, ZDP-189, COWRY-X, AEB-L, etc.... I'd like to try a kitchen knife in M4 though...or REX 121. Alas, the HAP40 will have to do for now.

I should say... stain resistant...

Cosay knives are made of hap40, cleancut.se selling them.

The steel is only part of the equation. The heat treat plays a large role in the outcome. I'll take Devin's AEB-L

I can't see why you need more edge holding than you get with R2 ala Mr Itou or Ryusen.

malexthekid said:

I can't see why you need more edge holding than you get with R2 ala Mr Itou or Ryusen.

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I have had many Itou knives... they are great, the HAP40 is a better steel for edge holding

But how/when are you meant to sharpen 😉

How does the Kohetsu cut compared to the Ikeda or other knives that you enjoy using?

what I find particularly interesting is that this line is available in wa- and ho-style. I prefer wa nowadays but like the look of the yo-handles of these knives...

The Hap40 is stain resistant. Cutting all kinds of food core steel edge takes on a golden hue. It is nice steel and like the other powders that I have used SRS-15, SKD, HSPS it is easy to sharpen as is AEB-L. Never used, sharpened or even seen ZPD-189 or Cowry-X. I wish I could so maybe put the powder steel hard to sharpen myth in the dustbin. I have had knives that are hard to sharpen mostly cheap stainless. My experience M390 is a little tough to sharpen.

Cuz of you have become a big fan of powder steels.:biggrin:

I think some people will always find certain steels to be "hard to sharpen" whether they are or not... Maybe best to judge for yourself

I would think it also depends what kind of stones you have?

Not really. It just depends upon the skills or experience of the sharpener.

I remember 4 or 5 years ago M390 was the buzz. I bought a spyderco to try it out. I really beat the crap out of it doing yard work. It had good edge retention, but found it took extra pressure behind the edge when sharpening. Later Mark from CKTG had some made. I remember thinking maybe not the best steel for chef knives. I do not see any made out of M390 these days. I have even had a few Japanese stainless that did not sharpen that well.

I am amazed how good some of the stainless knives are these days it is cool that the foundries are willing to make limited quantities for the high end kitchen knife market. I always felt that ease of sharpening is important as is edge retention eg. quick ups at work. Yoshikane SKD, Akifusa SRS-15, Hap40, custom treated AEB-L, have been around for a while & are proven. I think that Tojiro to their credit improved their powder steel knives over the years. I may be off but isn't the Gesshin Ginga steel the Japanese version of AEB-L? Anyway these steels are user friendly and work well for chef knives.

I think it would be nice to see SRS-15 & Hap40 used by other makers. I know some are with the Hap40.

Of coarse carbon steel can always be sharpened up unless to much rust along the cutting edge.:sad0:

ThEoRy said:

Not really. It just depends upon the skills or experience of the sharpener.

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This. +1

Remember were essentially rubbing metal onto rocks here. A good carpenter does not his tools blame

I like ginsanko a lot. (Hitachi silver 3). I have had a few knives made with this steel and I enjoy how easy it is to sharpen and the retention is quite good (all round 60-61 hrc). Had a few really bad instances of the knife falling on the floor (one where the edge made quite forceful contact the the ss leg of a workbench- not a single chip)

There are limits to this idea that the only variable is the skills of the sharpener. Try sharpening s110v on your bester and come back and talk about how your skill prevailed. We will know you're lying.

Or I suppose just have a different standard as to the meaning of sharp.

laxdad said:

How does the Kohetsu cut compared to the Ikeda or other knives that you enjoy using?

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Well.. the Ikeda I have has been thinned.... thinned to an extreme degree... so its geometry dictates that Ikeda in particular is a better cutter... but stock, the HAP40 is just as good if not better

keithsaltydog said:

The Hap40 is stain resistant. Cutting all kinds of food core steel edge takes on a golden hue. It is nice steel and like the other powders that I have used SRS-15, SKD, HSPS it is easy to sharpen as is AEB-L. Never used, sharpened or even seen ZPD-189 or Cowry-X. I wish I could so maybe put the powder steel hard to sharpen myth in the dustbin. I have had knives that are hard to sharpen mostly cheap stainless. My experience M390 is a little tough to sharpen.

Cuz of you have become a big fan of powder steels.:biggrin:

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M390 is a pain... have it on a few Benchmade folders...

ZDP189 has increased in price... I remember having a nice little Sanetu ZDP-189 Santoku that got blazing sharp.... was like $150... now it is impossible to find a ZDP-189 knife under $300

My experience with Cowry-x was from the KD line.... that is now the stuff of legend.... as is the price.

lucabrasi said:

There are limits to this idea that the only variable is the skills of the sharpener. Try sharpening s110v on your bester and come back and talk about how your skill prevailed. We will know you're lying.

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Yes there is actually truth to some steels being beyond the reach of some stones (although I wouldn't hazard to suggest either stones or steels). See this link for example: http://www.toolsfromjapan.com/wordpress/?p=713

Take in mind that while usually a HRC of the specific blade is given, depending on heat treat and contents some of the carbides within it can be far harder.
For example both vanadium and tungsten carbides are supposedly harder than aluminium oxide.

Ah yeah those s110v kitchen knives we all see so much of nowadays.... How could I forget! :razz: I agree there are limits and and perhaps would concede the abrasive used would impact the perception of how easy ie. How much work the knife takes to sharpen.

Fair enough that it's not in kitchen knives. Suppose I was thinking just sharpening generally, but you're right that the commonly available kitchen knife steels should be doable with regular stones. Including zdp.

lucabrasi said:

Fair enough that it's not in kitchen knives. Suppose I was thinking just sharpening generally, but you're right that the commonly available kitchen knife steels should be doable with regular stones. Including zdp.

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...because with ZPD they left out the vanadium, so there aren't any vanadium carbides that are harder than your stone...

I think by all means the 'hard to grind' pivots around the alloys / carbides, not the general HRC of the matrix.

Jovidah said:

Yes there is actually truth to some steels being beyond the reach of some stones (although I wouldn't hazard to suggest either stones or steels). See this link for example: http://www.toolsfromjapan.com/wordpress/?p=713

Take in mind that while usually a HRC of the specific blade is given, depending on heat treat and contents some of the carbides within it can be far harder.
For example both vanadium and tungsten carbides are supposedly harder than aluminium oxide.

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Not the first time have heard great reviews of the Sigma Power Select 2.

as ever there is always a trade off, if you are looking for something with super edge retention it is logical to assume it must be quite a tough abrasion resistant knife.

keithsaltydog said:

Not the first time have heard great reviews of the Sigma Power Select 2.

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I have had the power select 2's for a few years now and they do an excellent job on the harder steels for which they are designed. (For me they are for woodworking tools not knives). I use different stones for softer tool steels and the beginnings of my knife collection.

lucabrasi said:

There are limits to this idea that the only variable is the skills of the sharpener. Try sharpening s110v on your bester and come back and talk about how your skill prevailed. We will know you're lying.

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Got it. So Dave, Jon or even Murray Carter can't sharpen s110v on a Bester or a King. Unless of course they are lying.

I haven't read all of the posts, so may be missing part of the discussion, but Murray Carter did say in an interview that some steels are nearly impossible to sharpen by hand (he uses king stones afaik):

10. Are there some knives that you don’t like to sharpen?

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Any knife that is sold under the pretense of extreme wear resistance, such as the ZDP189 or VascoWear blades, are nearly impossible to sharpen by hand. I sometimes joke that the owners of these knives would be better served with a ceramic blade or diamond coated blade. It is not commonly known or understood that the primary requisite for a high performance knife is ease of maintenance, even before edge hardness and keenness. The Holy Grail in cutlery is a blade that only takes a few minutes to regrind and finish the secondary and primary edge and yet cuts flawlessly for hours on end. This is a great economy of effort. This is why I prefer to use the Hitachi White Steel, because it sharpens easily yet maintains an incredible edge. My last advice for those thinking about learning to sharpen by hand is save yourself a lot of time and effort and get my easy to watch and easy to understand instructional video for $25 as a digital download or $35 for a DVD.

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ThEoRy said:

Got it. So Dave, Jon or even Murray Carter can't sharpen s110v on a Bester or a King. Unless of course they are lying.

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Well there are certainly limitations... the vanadium carbides will be harder than the stone, so you'll be sharpening the matrix but the vanadium isn't going anywhere until it pops out. Maybe that's why Jon also uses diamond stones? Those would have no problem shaping the vanadium carbides.
As I said above, that's probably also why there's no vanadium in ZPD-189. Grinding down the molybdenum and chromium carbides is no problem but the vanadium carbides are simply harder than the aluminium oxide abrasive found in water stones. So you will be encountering at least some difficulty there.

ThEoRy said:

Got it. So Dave, Jon or even Murray Carter can't sharpen s110v on a Bester or a King. Unless of course they are lying.

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You can sharpen s110v by stone, it will take forever and you aren't going to get the best edge possible. Shapton Glass would probably be the best stone for S110V. Also it's the addition of Niobium (Nb) that creates carbides that are even harder than Vanadium.