Where's all the Blue 1?

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Barry's Knives

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I've noticed that of the Hitachi steels, blue 2 and white 2 seem to dominate and blue 1 is especially hard to come by and geberally far more expensive. Does anyone know why this is and are there any blacksmiths who are particularly good with it?
 

madelinez

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I'm not sure why, but around 6-8 years ago a lot of Japanese smiths switched from Blue #1 to Blue #2 or super aogami.
 

madelinez

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There are a fair few western makers that use 1.2442 which is similar to Blue #1 in terms of tungsten but half the chromium. It's not as pure as the Hitachi steels but still a good steel.
 

childermass

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Will Catcheside is one of these western makers.
I don’t own mine for a long time so no in depth thoughts yet. But as I wasn’t too fond of the ootb edge I touched it up on a Suita and it responded really well to this stone making a huge jump in sharpness.
 

madelinez

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Carbon steels alloyed with tungsten offer a really nice toothy edge when sharpened in the 3-6k range in my experience. It's probably dependent on the heat treatment of the knife but they really do well on overripe tomatoes.
 

lemeneid

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What I’ve read, blue1 is really brittle at the same HRC compared to blue2. And blue 2 can achieve really high hardness anyway.
And if you are aiming for edge retention, you’re better off with AS.
 

Paraffin

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Yoshikazu Ikeda uses Blue #1 in his Damascus (suminagashi) line of knives. I have three of those -- a 115mm petty, 119mm petty, and a 165mm nakiri. Very good edge retention on these knives, and they're easy to sharpen. I've never had any issues with brittleness/chipping, but I'm pretty careful with my knives.

I have a couple of other knives in aogami super that I like (a Takumi Ikeda gyuto and a Kohetsu honesuki), but the blue #1 is a little easier to sharpen than AS, at least with these particular knives. Better feedback on the stones. I wouldn't hesitate to buy another knife in Blue #1 from another maker who was good at working it.
 

Eloh

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Probably availability of prelaminated steel.
 

CiderBear

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Don't know if he's particularly good at it, but Yoshikazu Tanaka has been churning out lots of Blue#1 knives lately
 

ian

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The Mizuno KS I have is Blue #1, and is awesome. I’ve had it for a couple months (home use) and it hasn’t microchipped yet.
 

M1k3

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What I’ve read, blue1 is really brittle at the same HRC compared to blue2. And blue 2 can achieve really high hardness anyway.
And if you are aiming for edge retention, you’re better off with AS.
I would think AS would be chippier than Blue 1? It has more carbon, tungsten and vanadium.
 

Barmoley

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The Mizuno KS I have is Blue #1, and is awesome. I’ve had it for a couple months (home use) and it hasn’t microchipped yet.
Mine is promising too, but I haven't had it long enough to really know. No chipping so far which is more than I can say about some hard treated blue 2.
 

inferno

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What I’ve read, blue1 is really brittle at the same HRC compared to blue2. And blue 2 can achieve really high hardness anyway.
And if you are aiming for edge retention, you’re better off with AS.
Blue 2 can achieve 65 hrc or so so i agree, i simply dont see the point of using blue1, yeah sure it a bit higher W and higher C and that makes it more brittle and more abrasion resistant.
I think the blue 2 is the best overall compromise of all blue steels including O1 (blue 3,5 :) )

blue super has added V for grain refinement that increases toughness/strength, but its higher C and higher W so its probably less tough than blue2 and 1 anyway. maybe not much though.

i think they should rename them so that blue2 is called blue super because this the real supersteel imo. compared to other carbons at least.

-----------

Does anyone know who forges the kagekiyo line?
Kagekiyo is a premium line made by Baba Hamono. Every craftsman that works on this line is a certified master craftsman and it shows in the beauty and finesse of these knives.
https://carbonknifeco.com/collections/kagekiyo-knives
 

inferno

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I would think AS would be chippier than Blue 1? It has more carbon, tungsten and vanadium.
it might be a draw since the the added V content of AS increase toughness. blue 1 and 2 dont have V at all. but they still have w that is another grain refiner (or so i've read). V and Nb is more efficient though.

I think these steels were actually made to be run at different hardnesses. and you give up toughness they higher you go. its the price to pay kinda. and then the decrease in toughness is acceptable anyway.

i like w steels they feel the best of all on the stones.

here is some info on W steels.

https://www.ispatguru.com/tungsten-in-steels/
https://knifesteelnerds.com/2018/03...uper-the-facts-about-tungsten-alloyed-steels/
 

M1k3

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Maybe a wash between Blue 1 and AS. But don't say Blue 1 is chippier and then recommend AS, it has even more carbon.
 

Michi

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I enjoy my blue #2 blades. Very, very sharp, and they stay sharp a long time. The steel gets a patina, but doesn't rust easily, so I don't have to obsessively wipe them all the time. I've had no problems with chipping at all, and they are easy to sharpen (easier than SG-2). Of the carbon steels, blue #2 is the one I enjoy most. For stainless, it's a toss-up between SG-2 and SLD for me.
 

M1k3

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I enjoy my blue #2 blades. Very, very sharp, and they stay sharp a long time. The steel gets a patina, but doesn't rust easily, so I don't have to obsessively wipe them all the time. I've had no problems with chipping at all, and they are easy to sharpen (easier than SG-2). Of the carbon steels, blue #2 is the one I enjoy most. For stainless, it's a toss-up between SG-2 and SLD for me.
Whatever is used in the Takamura Chromax is really nice to sharpen also. I think, not sure, v-gin3b?
 

inferno

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Maybe a wash between Blue 1 and AS. But don't say Blue 1 is chippier and then recommend AS, it has even more carbon.
i would guess AS is chippier due to higher C content and W (carbide content). but AS might be close to blue1 at any given high hardness like 62-65 or so.

the biggest chemical factor with toughness is the c content and actual hardness.
and then carbide content.

and in stainless its the c and Cr that makes stuff more brittle in general.

there is some kind of thought behind the blue series anyway. otherwise they would just have one of them and run it from 55-65. and they dont.
 

inferno

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I think the idea/aim was something like this.

blue 2 - 61-62 hrc or so with fairly good toughness and fairly good abrasion resistance.
blue 1 - 63-64 or so hrc with a lower toughness but slightly higher abrasion resistance.
AS - 64 or so too but with higher abrasion resistance at the cost, if any, on toughness. slightly.

it might be academic though since all these would be classifies as ultra brittle steels.
 

Paraffin

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it might be academic though since all these would be classifies as ultra brittle steels.
What does "ultra brittle steels" mean in practice though? At least for the home chef, who isn't blasting through product in a commercial environment on a plastic cutting board?

I use hinoki wood boards for veg, and Hi-Soft rubber for soft raw protein. I don't scrape the board at 90 degrees with my knives and I don't rock chop. I have never had an "ultra brittleness" problem with my everyday home kitchen use of Blue #1 and AS knives. And that's all I use right now in my main knife rotation.

Your experience with this steel may well be different from mine, but it seems like hyperbole to call these steels "ultra brittle" as if that's a problem.
 

inferno

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What does "ultra brittle steels" mean in practice though?
it means its the most brittle type of steel you can get on this planet (except untempered full hard steels than can shatter like glass almost).

in practice it might mean a lot or almost nothing depending on how you use it.

I chopped up a few beer cans with my kurosaki AS santoku. and it chipped majorly (5x5mm) at maybe the 10th of them, sure aluminum is a soft metal.
I'd say it was above my expectations in toughness. it was one of the black hammered stainless clad ones in AS.

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want to expand on a few things though. in takefu village where they make the kurosakis for instance i have heard that there is only one heat treater and he does all the blades in some type of precise inudustrial oven, i'm guessing some kind of vacuum/inert gas system or so. and then you can get repeatable results. when doing lots of them. you know what you get, and you get the same every time.

thats a lot different to some guy hardening in charcoal. and then simply waving the blade over the charcoal for 30 seconds as tempering. like some fukking magic wand or something.

both types can be the exact same quality, hardness and grain size, but one of them has a very large potential of being out of spec quite a lot. guess which one.

there is also a lot of fantasy hrc figures thrown around that does not correlate to actual lab measured hardnesses. so i'd take everything with a grain of salt...

sorry for derailing the tread. but just because one maker says he does blue 1 at 64 hrc and another blue 2 a t 61. and another AS at 65 doesn't really mean that is the case. they can all be 62. or 60.
and then comparing stuff gets kinda hard to do.

i'd say its better to "buy the maker, not the steel". dont stare yourselves blind at the steels.
 

inferno

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What does "ultra brittle steels" mean in practice though?
i'd like to expand on this a little. a did some testing a few years ago. kurosak1 r2 at 62-63hrc or so. and mac cryoed asu8 at about 60hrc or so.
I cut cardboard since i needed to get rid of some big boxes.

I cut cardboard for maube 15-20 minutes or so with each knife. both had glass 4k edges on them.

the result was that the kurosaki had maybe 50-100 (or more) microchips in the edge when done. the blunting mechanism was through microchipping
the mac aus8 has 0 microchips. but instead it was just dull. rounded off.

and i'd say after 3-5 minutes or so they had both lost their really sharp edges, then it was simply a race to the bottom.

thats the difference between ultra brittle and not so much brittle. aus 8 is one of the toughest stainless steels you can find. very low carbide content too, and low carbon/Cr as opposed to the r2.

and when getting these sharp again i think it took me 3-4 minutes for the mac and and maybe 30 for the r2. so is it really worth it??
you be the judge. i'd say "sometimes". its all a compromise. all steels are.
 

Barry's Knives

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Would all this talk of brittleness impact on material selection for debas? For instance, the hide line uses b1, whereas nenohi use the presumably less brittle white steels. Am I therefore right in thinking the blue may hold its edge longer, but is more likely to chip and will be more difficult to sharpen than the white 2 steel knife?
 

Barry's Knives

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Would all this talk of brittleness impact on material selection for debas? For instance, the hide line uses b1, whereas nenohi use the presumably less brittle white steels. Am I therefore right in thinking the blue may hold its edge longer, but is more likely to chip and will be more difficult to sharpen than the white 2 steel knife?
And I'm specifically talking deba here as they tend to see more abuse than other knives
 

madelinez

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I always thought white was more brittle than blue. Most blue debas I've seen are 1-2 hrc lower than chef knives from the same maker.
 

inferno

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Would all this talk of brittleness impact on material selection for debas? For instance, the hide line uses b1, whereas nenohi use the presumably less brittle white steels. Am I therefore right in thinking the blue may hold its edge longer, but is more likely to chip and will be more difficult to sharpen than the white 2 steel knife?
debas are usually made with quite sturdy (high) edge angles, and they are usually sharpened with an extra high angle right at the edge to not chip out too fast. (you are also assumed to adjust this yourself if it chips out too fast for you and your use)

there is no guarantee that white steels are more tough than blue. i'd guess its the opposite. 1095 for instance 0,95-1% C pure carbon, is one of the most brittle steels you can find. and its almost never used in high impact applications above 58-60 hrc because of this (high impact for knives that, for real high impact stuff you use stuff like s5, s7, L6, 5160, and cpm3v and so on) . and even then you can find a lot of better toughness steels cheap. like L6, 5160 and so on. 1095 is mostly used because its cheap to buy and cheap to work. not because its particulary good. and whites are just higher carbon versions of this. imo that is.
 

inferno

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if you want a durable deba get aus-8 imo. it just works, just like linux.



 
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