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Why is utsuri rare on newer blades?


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I read that utsuri is fairly common in koto blades but not so much anymore. Why is that? Is it because sword smith became a lost art for some time?

 

On another note, I've been reading Fact and Fundamentals of Japanese Swords by Nobuo Nakahara, translated and co-authored by Paul Martin. There's a section where he describes that a battle-damaged kissaki has to be re-shaped and re-polished and that some of the mune must also be sacrificed or else the boshi will "soon wear away or run off." What does that mean? I don't understand why the mune can't simply be left alone.

 

Thanks,

James J

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You're asking good questions, James. Glad that you're digging in on understanding how & why Nihonto were made. The answer on utsuri is the same answer to why the exquisite qualities of Koto blades can no longer be duplicated. Back in Kamakura, the tosho who developed their techniques passed them on to their students by word of mouth, rather than writing them down where others might find their secrets. To simplify, then came many centuries of war, with constant battles that required swords to be made as quickly as possible, & tosho had no time to pass on the older techniques. Kazuuchimono is the term used to denote mass-produced swords from quality swords, as they were often deliver in bundles.Then, around 1600, the country was suddenly at (general) peace, & the tosho realized that those forging secrets were lost in time. Some few techniques have since been recovered, but not very many, & you'll find the term "utsushi" to describe modern efforts to recreate the old Koto hada & kitae, including Bizen & Soshu utsuri.

 

I don't have my Nakahara book handy, but I'm sure that someone else will chip in with the answer.

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Also, steel changed in the 1600s, becoming more uniform and homogeneous. It probably had an impact on utsuri. However, the art is not lost as modern smiths can produce utsuri.

 

As for the second question, if you have to reshape the kissaki (say, shorten it from a chu kissaki to a ko kissaki, the mune is inevitably shortened too. I imagine that’s what he means. But more knowledgeable people will chime in.

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I have some experience creating hamon and utsuri myself, what i learnt is that utsuri (at least the Bizen style one) is an effect of temperature transition, meaning that higher the difference of temperature between the ha and the mune and more likely it will appear.
The reason why from Shinto times to today is become more rare is simply because the style of hamon changed, swordsmiths create more "controlled" hamon with clay designs using higher temperatures of hardening having as result a lower difference on the various parts of the blade.
Anyway there are still some modern swordsmiths able to create it, this is a blade i own by modern tosho Keiun Naohiro
post-2051-0-86485300-1568785024_thumb.jpgpost-2051-0-32641000-1568785034_thumb.jpg

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There have been many arguments and discussions between various authorities regarding utsuri, whether it was intentional or accidental was it the result of the composition of steel used in the jigane., was it a form of secondary hardening and many others. Without offering a definitive answer (because I don't think there is one) there are a couple of things to consider:

1. The most prolific producers of blades with Utsuri were the Bizen Smiths. They are generally thought to have worked at lower temperatures when quenching a blade, hence the tendency to produce a nioi deki hamon and the general lack of nie in their work when compared to other schools. If this is the case then the formation of utsuri is not a result of high heat and is more likely to be related to the composition of the steel. Or at least the steel characteristics lent themselves to the formation of utsuri

2. Utsuri is seen on Bizen blades with a wide range of hamon including the suguha of the Oei Bizen smiths and the choji-midare of the Ichimonji den. Therefore the lack of utsuri in shinto blades is not likely to be due to the hamon shape.

3. As mentioned above in the shinto period the production of Tamahagane was centralised. This largely eliminated many of the individual characteristics seen in the jigane of individual schools/traditions and it is possibly this, in combination with the loss of knowledge mentioned previously, that resulted in shinto smiths struggling to produce utsuri. Many Shinto smiths tried to reproduce the utsuri of an earlier time but few succeeded and those that did such as the Ishido schools did so with limited success.

 

On a different note you mention you are reading "Facts and Fundamentals". This book contains some excellent information and is extremely useful. However I believe that some of the opinions expressed by Mr. Nakahara are rather radical and contradict many other sources. I think it is important to read other reference works alongside this as using it as a solitary source could offer a distorted view. 

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Believe it or not, I own a Chinese katana with a juka/ō choji Hamon that actually has a faint utsuri, so temperature and steel are definitely a factor here as most Chinese swords use a lower temperature to avoid cracking the ha during yakiire and their Hamon is Nioi based, never Nie

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To answer the question about the mune and kissaki repair, refer to the picture below.  2 drawings of the same sword with a broken kissaki: the blue is the hamon and boshi and the red is 2 different ways to do the repair.  In example 1 the kissaki only is reshaped.  What originally was a chu-cissaki remains a chu-kissaki but the boshi runs off the edge of the kissaki.  In example 2 the kissaki is reshaped and the mune is brought down also.  The kissaki becomes an ikubi or ko-kissaki, the boshi doesn't run off the edge and the kaeri (return of the boshi down the mune) is lost.  This is what Mr. Nakahara is referring to.

Grey

post-20-0-27416300-1568819337_thumb.jpg

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To answer the question about the mune and kissaki repair, refer to the picture below.  2 drawings of the same sword with a broken kissaki: the blue is the hamon and boshi and the red is 2 different ways to do the repair.  In example 1 the kissaki only is reshaped.  What originally was a chu-cissaki remains a chu-kissaki but the boshi runs off the edge of the kissaki.  In example 2 the kissaki is reshaped and the mune is brought down also.  The kissaki becomes an ikubi or ko-kissaki, the boshi doesn't run off the edge and the kaeri (return of the boshi down the mune) is lost.  This is what Mr. Nakahara is referring to.

Grey

That's a great illustration that explains it really well! Did you draw that?

 

 

On a different note you mention you are reading "Facts and Fundamentals". This book contains some excellent information and is extremely useful. However I believe that some of the opinions expressed by Mr. Nakahara are rather radical and contradict many other sources. I think it is important to read other reference works alongside this as using it as a solitary source could offer a distorted view. 

Which opinions of his do you think are radical? I suppose for that matter, what are considered standard views?

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That's a great illustration that explains it really well! Did you draw that?

 

 

Which opinions of his do you think are radical? I suppose for that matter, what are considered standard views?

 

Hi James,

 

If I remember rightly, one of them is regarding the question you posed regarding trimming from the mune side of the blade to preserve the kissaki. Mr Nakahara's suggestion is that the shape of older tachi, where there is pronounced koshi sori but a straightening towards the tip is due to the sword being repaired in this way rather than because it was the smith's initial design or for a functional reason when the sword was made. 

 

For me, Mr Nakahara's idea makes sense as I'm of the view that in koto times form following function was the primary driver of sword design or at least in this case the need to maintain the function of an expensive item such as a sword. 

 

Thanks for starting an interesting discussion.

 

I'll edit this to add the rider that I'm in danger here of being too definitive - it probably explains the shape of some swords. I occasionally forget that, with Nihonto, there are usually exceptions to every rule and that it is best to weigh each sword on its own merits or otherwise.

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Hi James

 

Which opinions of his do you think are radical? I suppose for that matter, what are considered standard views?

Having got in to some heated debate in the past on this I really don't want to repeat the experience. It is some time since I read Mr. Nakahara's book and as said it has some very good ideas in it. There are however a number of sweeping generalisations which are to say the least questionable. I cannot remember specifics (as said I read it a long time ago) but do remember feeling uncomfortable with some of his views.

I suggest you also read some of the longer established references, many of which are listed here and can be found from sellers such as Grey and you can then draw tur own opinions as to the validity of what is being said.

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The other of Mr. Nakahara's opinions that some might consider radical is that no great swords should be o-suriage.  No one ever would have shortened a sword from an important smith to the point where the mei was lost and therefore any o-suriage sword with kin zogan mei or paper to someone important is questionable.

Grey

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I believe there are several effects that are called utsuri and more than one factor that influences it’s appearance. Much of what is termed utsuri is probably banite which forms at a lower temperature than martensite. It appears that a differential application of heat was applied to facilitate the formation of utsuri (banite). The edge was heated more than the rest of the blade perhaps by heating a block of steel and then holding the edge to the lock. That’s how I have made it. I don’t see utsuri if I heat the entire blade to temperature then use the clay coating on the back portions of the blade to allow for differential cooling. That was the more common method of heat treatment during the late koto period and afterwards.

I also tend to see more utsuri if the exterior steel is more of a medium carbon content (40 or 50 points of carbon) and low alloy content. These ideas just reflect my limited experiments. I’m sure there are other valid ideas and methods that produce similar effects. Don’t look at this as anything definitive. Just some old random thoughts and memories.

Shannon Hogg

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