Creating utsuri

[Lukrez]

 

During the Edo period, with the end of major wars, the necessity for utsuiri declined, and it was no longer commonly produced. So Utsuri can only be found in older swords, crafted before this shift. As far as I know, Kunihira Kawachi managed to recreate this technique, which earned him the Masamune Prize. What are the specific challenges in recreating utsuri, and are there other swordsmiths who have mastered this process?

[Bugyotsuji]

Yes, many have attempted and a few have succeeded in recreating utsuri.

 

Once I read about a modern smith coming to the conclusion not too long ago that utsuri was a by-product of smiths pursuing sharpness, in a time when beauty was not quite so important. 

[Matsunoki]

To expand the question just a wee bit (with apologies)  exactly what is utsuri metallurgically speaking? I know what it looks like, I’ve read what it is visually described as, I know it can be tricky for a togishi to reveal but what is it? 

 

I also have a vague memory of reading that it was created by subtle variation in the depth and composition of the clay based coating prior to hardening……not sure if that was fact or opinion.

 

[Lewis B]

I seem to remember reading it was a thin covering of nie intended by the maker to instill additional strength in the blade thus making it less likely to fail under a combat situation.

[nulldevice]

1 hour ago, Lukrez said:

 

During the Edo period, with the end of major wars, the necessity for utsuiri declined, and it was no longer commonly produced. So Utsuri can only be found in older swords, crafted before this shift. As far as I know, Kunihira Kawachi managed to recreate this technique, which earned him the Masamune Prize. What are the specific challenges in recreating utsuri, and are there other swordsmiths who have mastered this process?

Did the inclusion of utsuri in blades decline because of lack of necessity or due to a lack of capability? We see a big decline in the overall quality of swordmaking in the mid-end of the Muromachi period before a revival again beginning in the peaceful edo period. This can be seen clearly in our modern lens just by tracking which periods of blades have the most Juyo+ swords out there. The need for swords was still presumably very high during the warring states era as there was fighting all over the country and we see many surviving swords from this period showing that swordmaking didn't stop, but that the average quality was lower.

 

Is it possible that over the ~200 years or so spanning the end of the Oei period (1394) to the beginning of the edo period starting around Keicho in 1596 that some traditions were lost? 

 

Edit: I would love to see some older documents from the Edo period, if they exist, discussing utsuri. Aesthetically, its very pleasing to modern collectors. But I quickly reach the end of my knowledge regarding polishing techniques in the 1600s being able to showcase utsuri, mention of utsuri in general, and if it was a desirable thing for swordsmiths to pursue in their artistic endeavors. I feel like I could probably find some answers in older surviving Hon'ami documents, or commentaries on family collections that have been passed down for generations. 

 

 

[Matsunoki]

I’ve had a couple of blades with distinct utsuri but it looked more like nioi……misty white rather than discernible particles. One was a large shinshinto Kinnoto style blade. 
Looking forward to seeing how this topic develops. 

[Lewis B]

ChatGPT's opinion

"It’s believed to be caused by slight variations in the composition of the steel used in the forging process. The technique of folding steel during the forging process (which is traditional in Japanese swordmaking) can result in these patterns appearing on the blade."

[Jacques]

Utsuri was rare in Shinto, but not non-existent. I won't go into the process of obtaining the utsuri, I'll leave that to the forum “experts”.

[Lewis B]

Markus Sesko has a nice essay on the subject.

 

https://markussesko.com/2013/08/22/some-thoughts-on-utsuri/

[Lewis B]

43 minutes ago, Matsunoki said:

I’ve had a couple of blades with distinct utsuri but it looked more like nioi……misty white rather than discernible particles. One was a large shinshinto Kinnoto style blade. 
Looking forward to seeing how this topic develops. 

I think it can form with both particles. Nie-utsuri being nie based.

[Robert S]

2 hours ago, Matsunoki said:

I’ve had a couple of blades with distinct utsuri but it looked more like nioi……misty white rather than discernible particles. One was a large shinshinto Kinnoto style blade. 
Looking forward to seeing how this topic develops. 

Agreed.  The Wakizashi that I have that has utsuri on it, it's definitely nioi utsuri.

[Matsunoki]

2 hours ago, Jacques said:

I won't go into the process of obtaining the utsuri, I'll leave that to the forum “experts”.

Why not replace the childish sarcasm with constructive explanation if you know the answer?

[C0D]

I have in my collection swords from Kamakura, Nanbokucho,Muromachi, Edo and modern with utsuri, so the utsuri never disappeared, just "fell out of fashion" cause other styles became more popular.
I also have some experience in making knives with modern steel in Japanese style, and i succesfully made utsuri in several.
First of all there are many kinds of utsuri, some i have no idea of how they're formed (tho i have some theories), but i'm gonna talk about what i found out by experience first hand and watching a Japanese swordsmith working that actually makes utsuri in most of his blades.
The utsuri i made is the most common style of utsuri is the one found in many Bizen blades (of course also in many others, but just to understand what i'm talking about).
The way to create that utsuri is actually "simple", you heat up the edge of the blade only to the temperature of quench, so the rest of the blade will have transitional temperatures which will turn out in different cristalline structures in the metal and different hardness, resulting in a different appearence once polished.
This can be done with or without clay or with clay only on the shinogi-ji to help control the temperature.
 

[Robert S]

58 minutes ago, C0D said:

The way to create that utsuri is actually "simple", you heat up the edge of the blade only to the temperature of quench, so the rest of the blade will have transitional temperatures which will turn out in different cristalline structures in the metal and different hardness, resulting in a different appearence once polished.
This can be done with or without clay or with clay only on the shinogi-ji to help control the temperature.
 

That's extremely interesting.  Do you have a thought on why in some cases you get that "hamon shadow" effect, with a gap between the hamon and the utsuri, and the form of the utsuri following the hamon approximately?

[C0D]

5 minutes ago, Robert S said:

That's extremely interesting.  Do you have a thought on why in some cases you get that "hamon shadow" effect, with a gap between the hamon and the utsuri, and the form of the utsuri following the hamon approximately?

In that case is because the whole area is not covered in clay, so the hamon is created naturally by the slightly uneven temperature and the steam that occurs when plunged in the water, since the temperature decreases in uniform way from edge to spine the utsuri would tend to have same shape of hamon.

Of course there are some specific cases that can also be made with clay, I assume Yoshii School used clay but managed to have a shadow utsuri, maybe just making deep ashi with clay

[Franco]

2 hours ago, C0D said:

I have in my collection swords from Kamakura, Nanbokucho,Muromachi, Edo and modern with utsuri, so the utsuri never disappeared, just "fell out of fashion" cause other styles became more popular.

 

"Fell out of fashion."  Hmm. I believe Albert Yamanaka would not agree.

[Franco]

2 hours ago, C0D said:

i'm gonna talk about what i found out by experience first hand and watching a Japanese swordsmith working that actually makes utsuri in most of his blades.

 

The name of this smith? Images of his work? Or even verbal descriptions? Type of utsuri he's producing? 

 

Thanks.

[C0D]

3 minutes ago, Franco said:

 

The name of this smith? Images of his work? Or even verbal descriptions? Type of utsuri he's producing? 

 

Thanks.

The smith is Kei'un Naohiro

[Franco]

While this appears to be utsuri, and this smith may have discovered a technique for producing this utsuri, sorry to say that it is no where near the level, quality, and control of utsuri seen and produced on earlier Koto period swords.

If only it were easy.

[C0D]

Just now, Franco said:

While this appears to be utsuri, and this smith may have discovered a technique for producing this utsuri, sorry to say that it is no where near the level  and quality and control of utsuri seen and produced on earlier Koto period swords. If only it were easy.

I never said he did master the old koto masters utsuri, and anyway those are just two examples that I actually own.

This topic isn't about who made the best utsuri, but how utsuri is made

[Franco]

3 hours ago, C0D said:

The way to create that utsuri is actually "simple", you heat up the edge of the blade only to the temperature of quench, so the rest of the blade will have transitional temperatures which will turn out in different cristalline structures in the metal and different hardness, resulting in a different appearence once polished.

 

26 minutes ago, C0D said:

I never said he did master the old koto masters utsuri,

 

Understood. Still, it needs to be made clear that there is a world of difference. Even between old swords there are significant differences between the types of utsuri. 

 

p.s. looking at your image again I would describe this utsuri as being more like a second hamon than genuine utsuri, a shadow of the hamon, a reflection of the hamon. 

 

 

 

[Rivkin]

Basic problem as I see it is the same as with wootz. There are popular smiths who claim to reproduce wootz and lecture extensively on their method. Their wootz looks... problematic.

There are a few whose wootz is close to historic examples. They are not telling too much about how they do it.

 

It is very clear that 90% recently (Edo+) steel even though its from tamahagane, it has very different thermal conduction properties compared to koto and it just does not harden similar to how koto swords did. There were always a few smiths who managed to produce hada which looked quite a bit more koto and a few who could produce reasonable utsuri. They are not too open about the secret sauce.

[Rayhan]

It has been a very long time since i had an inkling to comment on the board but since i am in Japan and saw some amazing Nihonto i just dropped by and saw this very interesting topic.

 

Utsuri is a result of the process of thermocycling the steel in different intervals befor yaki-ire. Koto smiths could not afford to make mistakes with their steel. Tamahagane was not in abundance (still isn't) and so thermocycling was used as a way to reduce any risk of issues when quenching. What we must do is look at the direct meaning of Utsuri (to change, to transition) those who own Koi will also understand Utsuri and its meaning. 

 

The swords were clay coated in cases and put through thermocycling many times before being quenched. New clay is applied at various intervals, removed and reapplied. This takes time and precission. This produces varying hardness at mm dissipation throught the koto blades.

 

In the later Edo period swords were made in different styles and made in more flamboyance with an emphasis on hamon and the Shinogi was not really part of the same outer jacket of the sword overall so this process was cut back. This also made production of blades faster (no doubt the lessons of cutting corners in the Muromachi period). 

 

And so those smiths that reproduced Utsuri in the Edo period and now are following an extensive, time consuming process when making their blades.

 

 

[C0D]

8 hours ago, Franco said:

 

 

Understood. Still, it needs to be made clear that there is a world of difference. Even between old swords there are significant differences between the types of utsuri. 

 

p.s. looking at your image again I would describe this utsuri as being more like a second hamon than genuine utsuri, a shadow of the hamon, a reflection of the hamon. 

 

 

 

same blade as the same picture, not a second hamon. I know how to look at utsuri 

 

another blade from same swordsmith, is this "real" utsuri?

 

1 hour ago, Rayhan said:

It has been a very long time since i had an inkling to comment on the board but since i am in Japan and saw some amazing Nihonto i just dropped by and saw this very interesting topic.

 

Utsuri is a result of the process of thermocycling the steel in different intervals befor yaki-ire. Koto smiths could not afford to make mistakes with their steel. Tamahagane was not in abundance (still isn't) and so thermocycling was used as a way to reduce any risk of issues when quenching. What we must do is look at the direct meaning of Utsuri (to change, to transition) those who own Koi will also understand Utsuri and its meaning. 

 

The swords were clay coated in cases and put through thermocycling many times before being quenched. New clay is applied at various intervals, removed and reapplied. This takes time and precission. This produces varying hardness at mm dissipation throught the koto blades.

 

In the later Edo period swords were made in different styles and made in more flamboyance with an emphasis on hamon and the Shinogi was not really part of the same outer jacket of the sword overall so this process was cut back. This also made production of blades faster (no doubt the lessons of cutting corners in the Muromachi period). 

 

And so those smiths that reproduced Utsuri in the Edo period and now are following an extensive, time consuming process when making their blades.

 

 

Who made this theory?
Do you have any evidence or experiment about this process?
This sounds an overly complicated process for someone who wants to reduce the risk of mistakes during hardening, not to mention this might give some extra internal stress. This would not be easy even with modern day tools.

[Rayhan]

This process is used widely in any manufacturing process today. When we make the turbine fans for aircraft we use thermocycling to reduce the stress and evenly distribute the hardening of the turbofans. All lessons learned form long long ago. It also takes a great deal of time to accomplish and you see the structure of the metals change. Anyway just my 2 cents, you can research thermocycling and understand the process and what the reults yeild. Thermocling reduces stress and does not amplify stress, depending on the result we want to create.

[C0D]

Just now, Rayhan said:

This process is used widely in any manufacturing process today. When we make the turbine fans for aircraft we use thermocycling to reduce the stress and evenly distribute the hardening of the turbofans. All lessons learned form long long ago. It also takes a great deal of time to accomplish and you see the structure of the metals change. Anyway just my 2 cents, you can research thermocycling and understand the process and what the reults yeild. Thermocling reduces stress and does not amplify stress, depending on the result we want to create.

Yes but doesn't create hamon nor utsuri from what I know, do you have any actual example of hamon and utsuri create by this method?

[Brian]

I agree with Rayhan. It's a well known process in manufacturing and only logical when forming utsuri. It's also the reason why utsuri follows the hamon, based on the repeated application of clay and allowing the smiths to control the shape and extent back then. They didn't do it just for looks...so only logical it was to reduce stress.

[Franco]

1 hour ago, C0D said:

same blade as the same picture, not a second hamon. I know how to look at utsuri 

 

another blade from same swordsmith, is this "real" utsuri?

 

If you know how to look at utsuri why are you asking me?

 

But, since you asked, utsuri? No, perhaps an utsuri like effect. Which is not the same. Saiha gives an utsuri like effect, but it's not utsuri according to Yamanaka. Effect is not the same as what my eyes are seeing. Even when you do see utsuri, it becomes apparent that certain types of utsuri are quite intentional. While other types are more incidental. 

 

 

Edited Thursday at 06:46 AM by Franco

[C0D]

9 minutes ago, Brian said:

I agree with Rayhan. It's a well known process in manufacturing and only logical when forming utsuri. It's also the reason why utsuri follows the hamon, based on the repeated application of clay and allowing the smiths to control the shape and extent back then. They didn't do it just for looks...so only logical it was to reduce stress.

So where are the blades that we know for sure are made with this method? 

[AlexiG]

The Kapp book was referenced in the Sesko article but here is the actual text from the book. Yoshindo Yoshihara is one of the modern smiths that can produce utsure and so can his student Oho Yoshimitsu (technically Yoshimitsu was his brother's student). The theory is heating the blade in distinct thermal bands along the edge given appropriate steel composition. FYI in case it helps the conversation.

 

Best,

alexi