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I’ll keep my comments in the realm of Japanese Honyaki...I don’t know the science or much about making knives but privately vendors of Japanese Honyakis have explained to me that often time Honyakis are heavier as is their nature. Can’t explain it, maybe harder steel just feels denser.
 

Michi

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and michi! white 2 rusts i think the fastest of any steel, and also discolors fast. and if you were to take a kitchen sponge to it to clean it up every week that "temper line" will definitely disappear sooner or later.

unless you polish it with a jnat uchigumori every week or so i'd guess. all honyakis are showpieces. sure you can use them but if you want that look youi will have to maintain it too.

personally i would just use it and wipe it. and then after like 6 months i would restore it to "new". if you know how to that is. and have the stones.
Yes, figures. I'm afraid that my enthusiasm for high-performance knives doesn't quite go that far. Still, each to his own. And they do look awesome. If someone manages to make a stainless steel Honyaki, I'll be the first one to buy it :)
 

lemeneid

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I have no doubt you are more versed in the matter than me! So I am going to challenge you at my own peril :D



this is what I am talking about when I say:



It is the master and not the material...



Perhaps. As I understand it, raw tamahagane is a good quality steel with high slag content. Folding was necessary to work the slag out of the bloom material. I believe this is the main contributing factor to hada (what choices were made during folding). Would the aesthetic affects be similar in bloom steels from other cultures? Probably. Could this be emulated with modern steels (even though folding them to work out slag is not necessary).... Probably!


Since this is a thread about unicorn hype being transient and katanas being irrelevant :p... Perhaps this is an appropriate location to say, that I wouldnt be surprised if the elusive Shigefusa clouds were hada due to folding wrought iron stock ;)
Every piece of tamahagane that comes out from the furnace is different. So it is up to the blacksmith to pick out the best pieces for what he is creating. Just chosing the pieces with high or low carbon, lots of jeweling or less jeweling, its a skill they learn over many years.
And also like I mentioned, the best smiths get to chose their pieces first. So if you aren't the best smith, you get the lower quality ones, and no matter the skill, there is only so much you can do with B or C grade tamahagane.
 

panda

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i think the best steel is iwasaki and that is said to be modern version of tamahagane which is the only reason i want to try the original stuff out of curiosity, none of this artisenal mumbo jumbo crap reasoning..
 

Luftmensch

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Can unicorns/hype/mystique last since for a long time? Sure! How about since the end of the iron age?

Every piece of tamahagane that comes out from the furnace is different. So it is up to the blacksmith to pick out the best pieces for what he is creating. Just chosing the pieces with high or low carbon, lots of jeweling or less jeweling, its a skill they learn over many years.
And also like I mentioned, the best smiths get to chose their pieces first. So if you aren't the best smith, you get the lower quality ones, and no matter the skill, there is only so much you can do with B or C grade tamahagane.
Perhaps we are speaking cross purposes a little? I am 100% down with what you are saying. I recognise the skill/craft/art that goes into all the steps (smelting the steel, forging the sword, polishing the sword - there are probably more). And these are not the same artisans: "many hands make light work"! I think this craft is valuable and is worthy of respect!


The subtlety I am trying to introduce is that the aesthetic beauty of a sword is a function of the artesans and not necessarily the material (tamahagane).

Tamahagane is decent steel that comes with baggage... The bloomeries didnt get hot enough to liquefy the iron. If you can melt the iron/steel, you can make it homogeneous and scoop the slag off the top of the liquid. Not so with blooms... Folding was used to compensate for the heterogeneous nature of the blooms and the large presence of 'impurities'. By folding many times the steel becomes more homogeneous and some of the 'impurities' are removed. Why do I use the scare quotes? Well.... what are impurities?

they also forge and and fold these pieces several times to get rid of contaminants in the steel. such as phosphorus and sulfur that makes steel brittle since these are non metallic inclusions.
@inferno is probably right. Im not sure - I don't know enough about blacksmithing... Those furnaces were a mess of iron, sand, steel and charcoal. As I understand it... 'impurities' in this context are the more macroscopic things (a.k.a slag, sand, charcoal). I don't know if you can reduce the phosphorus content (using these methods) if it is present in the ore?

Anyway... the material informed the process... the process informed the art (and no doubt there was a feedback loop). We have better materials now... But we can choose to retain the process. I don't see why an artesan couldn't start with a better quality steel, fold it several times (adding impurities if they wished) to produce a nice hada.

Maybe I am wrong. But I bet it is theoretically possible to make a sword that is visibly/practically indistinguishable from tamahagane swords using modern materials. Sure... It wouldnt be traditional. But it would look pretty. If so, surely that would rob tamahagane of any special status. If it has any, it is that it is a cantankerous, contaminated steel - like any other bloom steel - that is difficult to work with and does not offer any intrinsic benefits (functionally or otherwise) other than being labour intensive and lower quality than the modern alternatives. That in no way takes away from the artistry or is a slight on Japanese blacksmithing. It is an elegant solution given the technological constraints civilisation faced at the time... But it isnt the iron age anymore. ~1200 years have past! We can do better. And THAT is why it is romantic to me... Not everything has to be perfect or made by a machine.
 
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inferno

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Can unicorns/hype/mystique last since for a long time? Sure! How about since the end of the iron age?



Perhaps we are speaking cross purposes a little? I am 100% down with what you are saying. I recognise the skill/craft/art that goes into all the steps (smelting the steel, forging the sword, polishing the sword - there are probably more). And these are not the same artisans: "many hands make light work"! I think this craft is valuable and is worthy of respect!


The subtlety I am trying to introduce is that the aesthetic beauty of a sword is a function of the artesans and not necessarily the material (tamahagane).

Tamahagane is decent steel that comes with baggage... The bloomeries didnt get hot enough to liquefy the iron. If you can melt the iron/steel, you can make it homogeneous and scoop the slag off the top of the liquid. Not so with blooms... Folding was used to compensate for the heterogeneous nature of the blooms and the large presence of 'impurities'. By folding many times the steel becomes more homogeneous and some of the 'impurities' are removed. Why do I use the scare quotes? Well.... what are impurities?



@inferno is probably right. Im not sure - I don't know enough about blacksmithing... Those furnaces were a mess of iron, sand, steel and charcoal. As I understand it... 'impurities' in this context are the more macroscopic things (a.k.a slag, sand, charcoal). I don't know if you can reduce the phosphorus content (using these methods) if it is present in the ore? 1

Anyway... the material informed the process... the process informed the art (and no doubt there was a feedback loop). We have better materials now... But we can choose to retain the process. I don't see why an artesan couldn't start with a better quality steel, fold it several times (adding impurities if they wished) to produce a nice hada.

Maybe I am wrong. But I bet it is theoretically possible to make a sword that is visibly/practically indistinguishable from tamahagane swords using modern materials 2. Sure... It wouldnt be traditional. But it would look pretty. If so, surely that would rob tamahagane of any special status. If it has any, it is that it is a cantankerous, contaminated steel - like any other bloom steel - that is difficult to work with and does not offer any intrinsic benefits (functionally or otherwise) other than being labour intensive and lower quality than the modern alternatives. That in no way takes away from the artistry or is a slight on Japanese blacksmithing. It is an elegant solution given the technological constraints civilisation faced at the time... But it isnt the iron age anymore. ~1200 years have past! We can do better. And THAT is why it is romantic to me... Not everything has to be perfect or made by a machine.
1 i think its possible. otherwise all steel today would be filled with these impurities. i think they simply burn them off. either way forging and folding definitely purified the steel. because it was unusable without it.
P and S is the worst things you can have in steel pretty much.

2 tamahagane is not any kind of standardized formula. its just the method. it can be from like 0,6C or 1,5%C. its all tamahagane. also the more times you fold it the more carbon it gonna lose in the process. it gets cooked off as carbon dioxide and carbon monoxide.

I think almost all steels today are "better" than tamahagane. what you are paying for is that they make it from sand, it takes a long time and its scarce. and its all manual labor.

from what i have read, in japan they can only make a smallish amount of tamahagane each year. they are forbidden to do more by law.
the swords made out of tamahagane using all traditional methods are not classified as weapons, instead they are art or historical objects or something. if the same smiths were to make these swords out of 1095 they would be weapons = illegal. and they can only make a few per each smith per year. by law.

yeah time has passed since the 12hundreds. and now we have steels like cpm3v. which is tougher, and keep and edge a lot longer than anything from even 30 years ago. a lot. all in one package that you can mass produce if you want with machines.

one could probably chop down a whole forest with a 3v sword.

sweden is also a country where the steel making tradition is strong. but here we were just lucky to find good places that have very low % of non metallic contaminant ore. and this is still a very profitable export. the less refining/purifying you need to do to get top quality the more money you make.
 

inferno

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also on a sidenote in crucible steel like wootz for example. they have glass/sand in the crucible. when the sand/glass melts and the steel melts it goes through the molten glass several times up and down and then the silicon in the glass reacts and binds with certain contaminants and the steel is purified. also the glass is lighter so it stays on top protection the steel from oxygen.

i would guess this method produce steel that is 10-100 times more pure than the japanese method. since this is quite similar to modern industrial methods.
 

inferno

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i find this interesting regarding manganese for instance. most steel contain manganese. manganese is a purifier in steel. its almost never ever found in powder steel, since they are pure from the start. so no need for it. I remember reading kevin cashen saying its not wanted in high performance steel at all.
from wikipedia.

Manganese is essential to iron and steel production by virtue of its sulfur-fixing, deoxidizing, and alloying properties, as first recognized by the British metallurgist Robert Forester Mushet (1811–1891) who, in 1856, introduced the element, in the form of Spiegeleisen, into steel for the specific purpose of removing excess dissolved oxygen, sulfur, and phosphorus in order to improve its malleability. Steelmaking,[37] including its ironmaking component, has accounted for most manganese demand, presently in the range of 85% to 90% of the total demand.[34] Manganese is a key component of low-cost stainless steel.[32][38] Often ferromanganese (usually about 80% manganese) is the intermediate in modern processes.

Small amounts of manganese improve the workability of steel at high temperatures by forming a high-melting sulfide and preventing the formation of a liquid iron sulfide at the grain boundaries. If the manganese content reaches 4%, the embrittlement of the steel becomes a dominant feature. The embrittlement decreases at higher manganese concentrations and reaches an acceptable level at 8%. Steel containing 8 to 15% of manganese has a high tensile strength of up to 863 MPa.[39][40] Steel with 12% manganese was discovered in 1882 by Robert Hadfield and is still known as Hadfield steel (mangalloy). It was used for British military steel helmets and later by the U.S. military.[41]
 

Codered

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Does anyone know anything about the UHC (ultra high carbon) steel produced by the finish knifemaker Heilmo Rosselli. His knives are chunky and i don't like them but the steel is a type of wootz with 2.5 % carbon with no aloys, hardened at about 64hrc. it sharpens like white steel and holds an edge for a long long time (famous in rope cutting vids) it also doesn't chip easily. I wonder if this steel were to be forged by a more skilled knifemake what that knife would be like.
 

inferno

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i think its wootz. fairly sure of that. his version of wootz that is. might be produced by the old inidan crucible method no one really knows.

to get alloy banding in wootz you need some carbide former. i think the most common one in old wootz was vanadium in like 0,05-0,1% or so. and it came from the ore they used. look it up on youtube there are hours and hours on this there.

wootz was classically a softish matrix like 40-50 hrc or so with hard carbide (mostly Vanadium-Carbide iirc) banding in there (and maybe some Cr-C too). showing up as dendrites.

to maintain the dendritic structure of the carbide banding it needed to be forged in a special way back then (slow). not sure how its is now with modern stuff.

i have read that the rosselli blades dont cut too well because the profile. so you would need to take these to the stones. supposedly. i have not even seen one of his blades myself.

but if you ask me. putting 2,5% C in any steel without it turning into cast iron is quite an accomplishment. because thats usually what happens. the alloying elements segregates and then you have a frying pan.
this is no problem with powder steel but with ingot its impressive. very impressive.

this is probably the very exact type of steel/method that has been used in russia as bulat since the indan wootz period though.
 

ma_sha1

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I’d highly recommend not to “honey” me as I am a pretty rough looking old dude with beer belly.

That being said, I am new to the forum, would be very interested to hear your enlightenment regarding to Kato grinds...
 

Luftmensch

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i think its possible. otherwise all steel today would be filled with these impurities.
Oh definitely! I meant with iron age technology. In modern blast furnaces it is possible to add process to desulphurise, dephosphorise and desiliconise the metal. Increasing the basicity of slag increases desulphurisation (helps distribute sulphur into the slag). This is often done using lime as a flux. Dephosphorisation is an oxidation process and can be done using iron oxides and oxygen.

i think they simply burn them off.
Perhaps?

I am not particularly knowledgable about chemistry and metallurgy. Nor about how those processes were utilised and limited by old smelting techniques. Certainly; not being able to liquify the metal (as in a blast furnace) was a technological limitation and introduces challenges in decontaminating the steel.

This all said... The japanese iron sands are actually reasonably low in P/S content [see]. Perhaps what makes people think the iron sands are 'impure' is that for any given amount of iron sand, the content of iron can be low... really low. But this is not the same as being relatively high in P/S content!

what you are paying for is that they make it from sand, it takes a long time and its scarce. and its all manual labor.
Exactly.... Imagine starting with ore that has a marginal amount of the metal you are interested in. Processing it to yield 13 tonnes of slightly refined iron sand. Then gathering another 13 tonnes of charcoal. Now you smelt that for 70 hours to produce only 2.8 tonnes of bloom steel. But only the best quality parts of the bloom steel is used for tamahagane - so the yield is reduced even further to one tonne or less [see]. The yield is extremely poor. That is a heck of a lot of labour to make a decent (but not magical!) steel.

Again, I am no master in this subject matter. So this interpretation could well be 'impure'. Read it with a pinch of NaCl ;)



I think almost all steels today are "better" than tamahagane
Ha! Better? I suppose it depends how you measure 'better'. On yield and cost of production per tonne, I would say every commercial steel made today is better than tamahagane :cool:.

yeah time has passed since the 12hundreds. and now we have steels like cpm3v. which is tougher, and keep and edge a lot longer than anything from even 30 years ago. a lot. all in one package that you can mass produce if you want with machines.
True... But tsukumogami cant exist in machine made tools :p


sweden is also a country where the steel making tradition is strong. but here we were just lucky to find good places that have very low % of non metallic contaminant ore. and this is still a very profitable export. the less refining/purifying you need to do to get top quality the more money you make.
.... And so it goes.... full circle....

Kousuke Iwasaki was a respected metallurgist in the early-mid twentieth century. Much of the information about him on the (english) internet looks quite concentrated - only a few sources that probably copy/reference each other. While I take this information at face value, it would be nice to read some material that gave the sense of being more authoritative.

I read he was the one who developed the coloured paper classification system for japanese steels (yellow/white/blue). He married historical blacksmithing with scientific principles and modern knowledge. Like today, tamahagane in the mid twentieth century was scarce - so he searched for a substitute. After studying various options Swedish steel was selected as an alternative that had similar properties.

As much as we build a mythology around tamahagane, I rather imagine a mythology around the 'purity/quality' of Swedish steel has grown in Japan. Today Japanese knife manufactures use Swedish steel as a selling point.... It is not that I doubt the quality of ore or steel from Sweden. But as we have already discussed, modern furnaces can control the quality of their output fairly well. Because of this, the output quality (steel) isn't as strongly linked to the input quality (ore) as it was in the past.
 
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Barclid

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I’d highly recommend not to “honey” me as I am a pretty rough looking old dude with beer belly.

That being said, I am new to the forum, would be very interested to hear your enlightenment regarding to Kato grinds...
Oh, honey.
 

lemeneid

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from what i have read, in japan they can only make a smallish amount of tamahagane each year. they are forbidden to do more by law.
the swords made out of tamahagane using all traditional methods are not classified as weapons, instead they are art or historical objects or something. if the same smiths were to make these swords out of 1095 they would be weapons = illegal. and they can only make a few per each smith per year. by law.
thats not fully true. Raw tamahagane ore and sand is just banned from export, they can use however much they want domestically though, but the number of mines is dwindling which indirectly implies the quality of the tamahagane being produced now is also getting lower in quality. Which makes it even more important that only the best smiths get to use tamahagane now.
 

pentryumf

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tamahagane is steel made with the traditional method of pouring and burning charcoal and iron rich sands in a "tatara" clay smelting chimney kinda. this is usually a 36-72h or so process.

the end result is a low density sponge clump of steel. or aka bloom steel.


they spark test the pieces to determine carbon content. and they grade these from highest to lowest. usually a katana is made out of at least 2 different kinds. with the same HT the high and low carbon steel will become softer or harder. and with these types of steel it means the lower carbon content steel is tougher and is used for the spine or sides or center of teh blade and the high carbon one becomes the edge.

they also forge and and fold these pieces several times to get rid of contaminants in the steel. such as phosphorus and sulfur that makes steel brittle since these are non metallic inclusions. modern steel can have 0,003% or so of these. and tamahagane will not be close to this no.

modern steel is so good you dont need to make a sword out of 2-3 different C% steels. you can use one single steel and through hardening it (same HT all over) and it will be tougher, harder, and keep an edge longer, and chip less, and so on. you can also just as well use something like 1070-1080 stright carbon steel. and then temper the spine to lower hardness/higher toughness with a torch after the regular tempering. tempering is not the same as hardening.

i made a sword myself out of 80crv2 from krupp. and i'm fairly certain it will outperform any tamahagane sword ever created in all performance categories. by far.
Did you seriously make a sword, and if true can I see a picture of it? Please?
 

inferno

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i have not made a sword out of tamahagane no.
i made a sword out of 80crv2 @60hrc which is about 700% higher performing.

i made this about 6 months ago. its just rough ground, hardened, then tempered. have not had the time nor motiavtion to put a handle on it.
gonna be masur birch though. a stump that my grandfather game my father. and now i have it. and its gonna be the handle.

40cm blade, 20cm tang. it was the longest i could fit in my oven to temper it properly.

i built this mostly so i can have it on my back when i ride to work and back. you know, to eliminate "unforseen problems" and such.
getting home safe and sound.

sword1.JPG


pre harden grind



 

banzai_burrito

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i have not made a sword out of tamahagane no.
i made a sword out of 80crv2 @60hrc which is about 700% higher performing.

i made this about 6 months ago. its just rough ground, hardened, then tempered. have not had the time nor motiavtion to put a handle on it.
gonna be masur birch though. a stump that my grandfather game my father. and now i have it. and its gonna be the handle.

40cm blade, 20cm tang. it was the longest i could fit in my oven to temper it properly.

i built this mostly so i can have it on my back when i ride to work and back. you know, to eliminate "unforseen problems" and such.
getting home safe and sound.

View attachment 78170

pre harden grind



Somewhat off topic, but that giant santoku with the handle partially on. Is that a knife you made?
 

Runner_up

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IMHO:
Munetoshi Kurouchi Gyuto 240mm

I do have quite a few kniwes in the +1000 USD category, but this one is still one of my most prefeered cutters.
It´s not in stock right now, but it often is.
It is so good, that I had to buy an extra in the same size. Jut to see if my first one was representing the standard or a knife that came out extraordinarily good. The second one was as good as the first.
Agree with you there. Kato, Shig, Heiji, TF, Toyama, Yoshikazu Tanaka - at this point I own and enjoy a lot of the "greats", but man, the Munetoshi knives are outrageous. I've been thinking about buying backups because I believe in them that much.. Wish I did it when they were on sale.
 

ian

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i built this mostly so i can have it on my back when i ride to work and back. you know, to eliminate "unforseen problems" and such.
getting home safe and sound.
Probably effective! It used to be that a sword on your back would show everyone you were not to be messed with. Now it indicates you’re a crazy person. Same effect though. They stay away.
 

inferno

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Somewhat off topic, but that giant santoku with the handle partially on. Is that a knife you made?
i made a thread when i finished it. i'm not really good at finishing knives. but i'm good at starting projects.
 

inferno

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Probably effective! It used to be that a sword on your back would show everyone you were not to be messed with. Now it indicates you’re a crazy person. Same effect though. They stay away.
carrying knives here is illegal and you go to prison for it.
 

M1k3

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But swords are ok? Can you carry a pocket sword?
 
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