Muji Hada

[Ruben]

Hi gentlemen,

 

at the time I´am very interested in shinshinto blades, especially the ones made in bizen tradition.

Is there a good reason to produce muji hada? I mean the fact that the steel gets very hard sounds to me clear.

I can imagine that the blade will gets more difficult to temper. Also its much more work to produce such a fine grain.

So what is the reason for it? Shure in the very late edo period there was a radical change in producing swords, but is it realy just tradition?

I can imagine that the eye is focusing more on the hamon, in fact it does, but for practical use ... i dont now

One theory I heard is that some blades where made from old nails, so it was possible or necessary to end up in such a hada.

Or did the smithies in the late shinshinto period use a powerhammer?

 

Cheers

 

Ruben G.

[cabowen]

The steel is not necessarily harder, it has simply been folded and refined more.

[Ruben]

Hi Chirs,

 

I asked Dr. Kiyonobu Kato (NBTHK member since 1957), he told me just the steel is very hard and the hada is beautyfull, so... I wasn´t realy satisfied with this anwear :? . Ok maybe cause I needed like 10 minutes to explain what I mean, there where difficulties with language.

 

Greatings

 

Ruben G.

[Jamie]

More refined steel is naturally going to be harder, with a higher carbon content.

[cabowen]

It may or may not be harder or have higher carbon content. The hardness depends primarily on the both the carbon content and the quench rate. If the steel has has been folded more, chances are it will have a lower carbon content than steel starting with the same amount of carbon that has not been folded as much as carbon is lost the more the steel is in the forge.

 

The final carbon content of shinshinto blades is usually thought to be higher than koto blades as they are generally harder. They start with higher carbon and finish with higher carbon. The hardness is indirectly related to the folding....

[Ted Tenold]

More refined steel is naturally going to be harder, with a higher carbon content.

 

It doesn't work that way Jamie. The end product relies on the initial raw material. In the process of refining, the billet is re-heated. Every cycle results in a small loss of carbon.

 

@Ruben; muji hada is often called that because of older terminology carried forward to contemporary nomenclature. The polishing process in the Shinshinto period didn't refine the surface in a way that allowed what we otherwise can see today due to advances in the process. However, it is still very very fine and a result of more folding of the steel billet. Simply stated, it's part tradition, and part necessity. Making the hada so fine allows the smith to create hamon with denser or more concentrated habuchi, smaller and/or more vibrant defined patterns such as chojiba or juka chogi, and promote a more consistant propogation of nie and nioi based activities throughout the blade. Courser hada would result in the same patterns following larger strata of the hada, and diffusion of the habuchi. But it's a balancing act because if the steel is overworked, the hardenability is compromised and the creation of martensite becomes difficult. The smith must choose material that will work down in carbon to the acceptable concentration needed to promote the desired yakiba.

[Jamie]

It seems my statement wouldn't hold true in hand worked situations.

I didn't think of it that way, thanks for the correction.

[Ted Tenold]

Also adding on to Chris's statment regarding shinshinto being harder; the hardness of the steel can be a product of origins and manufacture as well. Imported steel used by Japanese smiths had different working properties than indigineous material, and could include elements that could create hardness beyond just carbon content.

[cabowen]

Making the hada so fine allows the smith to create hamon with denser or more concentrated habuchi, smaller and/or more vibrant defined patterns such as chojiba or juka chogi,

 

Not sure I follow you here....can you elaborate?

[Ted Tenold]

A bolder hada, i.e. an extreme such as ayasugi hada, can interfere with the shape of a pattern such as say, a chojiba pattern, obscurring it because of martensitic interactions along the varied strata. So at some level the hada and hamon have to accomodate and support each other. The Nihonto Koza Shinshinto edition notes this fact on page 213 in the following comment in the section covering "Processes for Jihada and Hamon";

 

In the case of the above mentioned kobuse (makuri), since the surface steel is uniform, this is a forging method that is suitable for tempering a hamon such as a nioi deki choji midare which does not have clumped nie and sunagashi in the ha.

 

When one thinks of some of the later patterns that Mishina/Yoshimichi school smiths made such as Sudareba, Suikiku, etc., it's evident that a finely latticed hada supports clarity of the pattern better than larger (or combined) patterns which would become obscured by heat treating interactions in larger patterned hada. Hada creates the activities we enjoy and supports the basic patterns, but misguided, ill-conceived or unskillfully assembled, will only created a confused and unbalanced piece. Kiyomaro's works are a classic example of skillful development and competence. His works combined masame and mokume and at the point at which he effectively placed the yakiba promotes an interface of activities in the mokume and masame juncture that provides depth, clarity, and form.

 

I once had a Gassan Sadakatsu daito with suguha. The hada was classic hallmark Gassan Ayasugi, but the combined steels in the construction were both finely forged (and the pattern very faint) and of very similar composition so the the suguha wasn't too disrupted and "wild" as it might have been with vastly differing composition layers that would promote more strings of hotsure and sunagashi in the habuchi. I found it to be of luminary competence to create such a piece true to the roots of Gassan, without overstating them at the same time.

 

The construction creates the canvas (hada) that must be compatible with the image (yakiba) drawn.

[John A Stuart]

A good explanation. John

[cabowen]

Since Bizen smiths made chojiba for at least 500 plus years before the shinshinto era, I can't completely understand the statement:

 

"Making the hada so fine allows the smith to create hamon with denser or more concentrated habuchi, smaller and/or more vibrant defined patterns such as chojiba or juka chogi"

 

Though I do agree that the construction/hada and hamon should work together.

 

Kobuse/makuri is a construction type independent of forging and it does not place a seam above the edge where two different steels intersect and thus makes for a uniform "canvas", if I can borrow your metaphor. Kiyomaro is noted for using a construction that does place a seam along the edge and this is where sunagashi and the like tend to form.

 

One can still get sunagashi and nie with a thick, diffuse habuchi in a tightly forged blade. I have a Shibata Ka back from the polisher recently that has very tight hada and clouds of ji-nie all over, becoming yubashiri... Conversely, some of the most vibrant choji imaginable occurs in koto Ichimonji which are not known for their muji hada.....Seki blades are known for their yaki-shimari yet many show o-hada as well...

 

I think the composition of the steel and the control over the way the blade is hardened contribute more to the end result than the tightness of the forging....Depending on the steel composition of the hada, the type of hada may or may not have much of an effect.

[Ruben]

Thank´s to all for the good explanation´s!

I will try to understand the details.

I´am still beginner so it gets more and more interesting .

 

There is a pic, not much to see and also the very unspectacular part of the blade.

If desired I will post few others, when it is back from koshirae making.

 

Sincere thanks are given to all!

 

Ruben G.

[Ted Tenold]

Since Bizen smiths made chojiba for at least 500 plus years before the shinshinto era, I can't completely understand the statement:

 

"Making the hada so fine allows the smith to create hamon with denser or more concentrated habuchi, smaller and/or more vibrant defined patterns such as chojiba or juka chogi"

 

Though I do agree that the construction/hada and hamon should work together.

 

No disagreement from me on this Chris. My statement was in the context of what some Shinshinto makers were striving to acheive as an end result. I'm thinking of some of the really concentrated and consistant nioi habuchi such as Sokan, or fine nie such as Ozaki Suketaka which will depend on *both* composition and hada.

 

Kobuse/makuri is a construction type independent of forging and it does not place a seam above the edge where two different steels intersect and thus makes for a uniform "canvas", if I can borrow your metaphor. Kiyomaro is noted for using a construction that does place a seam along the edge and this is where sunagashi and the like tend to form.

 

Agreed...and where he chose to place the yakiba in conjunction with that seam promotes the formation.

 

One can still get sunagashi and nie with a thick, diffuse habuchi in a tightly forged blade. I have a Shibata Ka back from the polisher recently that has very tight hada and clouds of ji-nie all over, becoming yubashiri... Conversely, some of the most vibrant choji imaginable occurs in koto Ichimonji which are not known for their muji hada.....Seki blades are known for their yaki-shimari yet many show o-hada as well...

 

I think the composition of the steel and the control over the way the blade is hardened contribute more to the end result than the tightness of the forging....Depending on the steel composition of the hada, the type of hada may or may not have much of an effect.

 

Again agreed. My example of the Gassan sword was an effort to demonstrate that composition also plays an important part.

 

I'm not trying to split hairs on the matter at all, and my comments were not intended to be a generalization in a world of exceptions. Composition is absolutely a player in the outcome. Again, my comments were in context of some of the shinto and shinshinto makers. I'm pretty sure we're in agreement on the subject overall.

[Brian]

Thanks Ted and Chris, I think some very good and interesting info.

 

Brian