"Good Bones"??

[chuck]

Every now and again in the discussions here, the phrase "good bones" crops up. What exactly does this mean? How do you check to see if your tsuba's bones are good or not? If a tsuba has "bad bones" is there a way to fix it?

 

Just trying to keep on learning.

 

peace.

[John A Stuart]

Tekkotsu or bones are the result of the forging process. They are nodules of different steel composition in non-homogenous steel. When tamahagane is folded it homogenises the steel grades so that the carbon content becomes consistent through-out. Tsuba not requiring such a consistent homogeneity does not require such multiple folding and welding. This allows the different steels to be visible, esp. at the edges. This has become a desirable feature and a way of determining the type of tsuba. There are good bones in that they are abundant and/or easily seen, but, there aren't bad bones in the other sense. John

[Grey Doffin]

Hi Chuck,

Picture of bones. These are good.

Grey

[sanjuro]

Grey.

Good example to pick.........Yamakichibei? You sort of expect good bones in a yammy. :D

[Grey Doffin]

Hi Keith,

Yes Yamakichibei: #12 in the Holbrook collection I've been selling.

Grey

[Henry Wilson]

That tsuba is half mine, half David Stiles.

 

viewtopic.php?f=4&t=8936

 

Permission to use the image would have been thoughtful...

[jrs]

Can someone elaborate? I see rough spots and dimples, etc...but I still don't understand exactly what "good bones" refers to on the example picture. Maybe if someone can highlight the areas it will help.

[Steve Waszak]

Here is a good example of good iron bones. The first and last images in this group of five are especially illustrative... This is a pre-Edo Kanayama tsuba...

 

Cheers,

 

Steve

[ububob]

Think lumps and irregulariities and you'lll be close enough. Like the man said, "Ain't no bad bones!" :D

[Surfson]

I have had it explained to me that bones emerge as the tsuba rubs on the kimono of the wearer, and the harder iron wears down more slowly than the softer, exposing the bones. In other words, one tends to see them primarily on quite old tsuba, and they weren't there immediately following the construction. Can anybody confirm or refute this view?

[watsonmil]

Dear Robert, ....

I have a bridge in Brooklyn, NY for sale at a most reasonable price. Contact me for details.

... Ron Watson

[Soshin]

That tsuba is half mine, half David Stiles.

 

viewtopic.php?f=4&t=8936

 

Permission to use the image would have been thoughtful...

The presence of "iron bones" the Japanese term is tekkotsu (鉄骨) was one of the deciding factor for me to acquire the tsuba for my collection. The first three generations of the Yamakichibei all had good tekkotsu. I am also leaning towards more tosho or kakushi style tsuba for my collection. I will give Gery half permission as posting photo of the tsuba was for educational and not commercial reasons.

 

 

 

Yours truly,

David S.

[Henry Wilson]

I give half permission too :D

[sanjuro]

Robert.

 

Man, you are gonna wear out a whole passle of kimono's over a few lifetimes trying to wear away the soft iron on a tsuba to expose the bones. You Have been somewhat misinformed I fear.

Incidentally, when you have made a down payment on the Brooklyn Bridge I have a nice little battleship for sale, also the starship Enterprise, at very competetive prices. Both Ron and I take Paypal. :D :D :D

[jason_mazzy]

you guys are all hillarious. nice to see the lighter side of the guys coming out.

[Surfson]

You guys can't fool me - I already own the Brooklyn bridge. By the way, 500 years is a long time. Have you ever seen the wear on an old coin, kashira or umabari just from handling? Ever seen a kozuka so worn by use that you can't make out any of the carvings? Smug you are, but a lot to learn have you.......

[jrs]

So why are " good bones" considered good. It seems like rough craftsmanship to me. I understand it can be indicative to a particular school or maker but it still seems lazy to me unless the out coming effect was completely intentional at the time of manufacture. just trying to understand.

[Henry Wilson]

I think that some effects (dare I say "activity" ) can be brought out on the surface of a tsuba from handling over a very very long period of time. A bit like acid etching in a way from the sweat etc on hands. I am not so sure about heavy bones being brought out though....

 

Also the idea of bones started in armour and were desirable as they are generally harder than the surrounding metal making the armour a little more robust. I think this technology was brought / carried into tsuba, probably with the idea of making them stronger against stray sword strikes.

 

I have heard some people call bones ugly blisters, but I personally like a nice knobbly rim

 

BTW the above information is what I have read somewhere and what I can recall of it. I am no specialist in this topic so please go easy.

[watsonmil]

Dear James & Robert,

I think overall the presence of bones or more correctly " tekkotsu " has more to do with aestetics than any particular function. The reason for tekkotsu is that the maker left impurities of harder steel in the iron, bits of iron harder than the majority of the iron in forging the tsuba. So there are hard lumps mixed into the skin. They work their way to the edge ( mimi ) during the forging process though some can also be seen in the tsuba face ocassionally. Several schools used this effect right up into the Edo period. Perhaps someone else could explain better than I, ... but this is my way of expaining the occurence. It is often considered that a tsuba is well forged with the appearance of tekkotsu, as it takes a good deal of forging to force the harder bits to the edge. Kind of difficult to understand in my poor but

basic explanation. " Oh, Dem Bones, Dem Bones, Dem Dry Bones, ... now Hear the Word of the Lord " :D .

... Ron Watson

[Marius]

There is an excellent article by Boris Markhasin and Andy Mancabeli - it deals with the technical and functional side of tekkotsu.

 

You might want to google "Muromachi Period Iron Tsuba & Armor – Similarities in Material, Function and Manufacture"

[Martin]

Hi Robert and all,

 

there are indeed sources on the Internet that state, that Tekkotsu might be formed by wearing the Tsuba close to thr Kimono (see this oner for example: http://www.ksky.ne.jp/~sumie99/tekkotsu.html ).

In my opinion these are "impurities" emerged during the forging process. But of course not all Tsuba show Tekkotsu as thie depends on the material and the specific kind of forging.

Iron bones had a certain attraction and are related to the "tea taste" that developed in the 16th Century emphasizing simplicity, rusticness and other humble qualities in the tea ceremony. These aethetic principles were incorporated in many other parts of Japanese art and handcrafts.

For some Tsuba schools those bones are Kantei (attribution) points.

There are also Tsuba where the Tekkotsu has been simply filed off as they did not meet the aesthetic demands of the artist.

 

Just my quick thoughts....

[Ford Hallam]

The appearance of tekkotsu is, I believe, correctly regarded as evidence of the method by which the steel was processed and the qualities of the raw material that was utilised.

 

As part of my own research into this subject I've been speaking at length with Sumihira Manabe and Pierre Nadeau about this. Manabe San is well known for his somewhat controversial ( in some circles anyway ) views on early steel production. He maintains that older swords that exhibit such striking differences in steel quality are impossible to replicate using the sort of standardised material that is being supplied by the NBTHK. It's this lack of character that has lead many of the leading smiths to begin making their own steel. The DIY approach is yielding some very promising results and a far better and more intimate appreciation of the material among those who make it.

 

Anyway, I asked Pierre to select some particular pieces of raw, second grade tamahagane and to work them only as much as was needed to create a single plate of steel without any obvious cracks or other unwelded areas. He tells me this was possible in only 4 folds and that from what he can see the slag has been pretty much eliminated. You can hear the blanks ring here.

By limiting the folding process to the bare minimum the material may remain sufficiently unhomogeneous so as to exhibit the same sorts of lumpiness that older guards show once subjected to certain finished processes.... which remain to be established :?

 

From what I understand though the NBTHK tatara steel is reasonably consistent stuff and large variations in carbon content are not seen in individual pieces of the sorts of sizes one would think would be used to produce a tsuba blank. It may be a matter, as some have suggested, of smaller lumps of higher carbon tamahagane being working in between larger plates of much lower carbon steel....I'll try all the options :D

 

I'm expecting delivery of 2 of these plates this week. I'll be sure to report on the results of our experiments and any successful replication of iron bones will be seen here first.

 

regards,

 

Ford

[Ford Hallam]

You guys can't fool me - I already own the Brooklyn bridge. By the way, 500 years is a long time. Have you ever seen the wear on an old coin, kashira or umabari just from handling? Ever seen a kozuka so worn by use that you can't make out any of the carvings? Smug you are, but a lot to learn have you.......

 

The sort of wear you may be referring to I imagine, is generally seen on shakudo kozuka and other copper alloy fittings. For the purposes of comparison you can regard shakudo as being essentially much like pure copper.

 

Consider these Typical Hardness Values:

 

pure copper 35

mild steel 120

Hardened tool steel 650 ~ 700

 

 

 

It should also be pointed out that simple hardness alone is not the only factor to consider in relation to wear resistance. The micro structure of the alloy/metal is a very significant indicator.

[IanB]

All, I would have thought that an early tsuba maker would really have preferred to use the softer iron rather than a steel. Iron would have been perfectly suitable for the purpose and be much kinder on the tools used to pierce and chisel the work. I would suggest that many a tsuba maker cursed when running into a hard spot - I know I have when working iron castings which can destroy the edge of a steel tool in seconds. As for the 'wear', some is bound to happen through handling and rubbing, but simple oxidation must have also played a large part.

Ian Bottomley

[Surfson]

Glad we've moved from the ridicule stage to a real discussion on this. The article Mariusz linked to is quite good and provides some insight. Ford, I agree that iron is harder and wears more slowly than soft metal, but I have had many very old iron sword parts that are quite worn, and not from abuse or neglect. The concept that old iron tsuba with bones result from wear was introduced to me at a special presentation by a tsuba expert (I don't remember his name) at the Chicago Sword show two or three years ago. He had many wonderful tsuba on display and spoke about many features as well as kantei and dating. As I recall, he made the point that the bones tend to be on the lower left of these guards as you face the front, since that is the region that comes in most contact with the kimono for a right handed samurai. Anyway, I have tired of the upkeep with the Brooklyn Bridge, and am willing to sell it at a good price if anybody is interested. Cheers, Bob

[Ford Hallam]

Hi Bob

 

I have had many very old iron sword parts that are quite worn, and not from abuse or neglect.

It may be that some of this apparent wear was deliberate and dates from the time of manufacture.

 

Of course, to date there exists no one bit of actual scientific analysis to validate these various speculations regarding the carbon content lumps in these tsuba. It is merely assumed that they are harder and therefore are prominent as a result of the softer areas having been worn away. In terms of oxidation and corrosion the higher carbon areas will be reduced more rapidly than purer iron, especially when subjected to high heat.

 

As I recall, he made the point that the bones tend to be on the lower left of these guards as you face the front, since that is the region that comes in most contact with the kimono for a right handed samurai.

This would beg the question, how were all the tekkotsu on the face of Kanayama guards rubbed into prominence and how do we explain the lumps where it's clear the tsuba didn't rub against the hakama. I'm sorry but this notion simply doesn't stand up to even superficial scrutiny. To allow that it may be a possibility requires far too many other aspects to be ignored as inconvenient.

 

I've always been a bit hesitant to take the opinion of tsuba experts as gospel myself. One should always ask;" how do you know that?" In my experience of tsuba experts the view from their armchairs is somewhat limited.

 

Anyone who conducts an argument by appealing to authority is not using his intelligence he is just using his memory. Leonardo Da Vinci

 

regards,

 

ford

[sanjuro]

Regarding the theory that a tsuba wears from contact with the kimono or hakama:

When worn correctly, a katana is thrust edge upward on the left hip between two layers of the obi which is wrapped around the waist 2 or three times. It can only be worn as closely to the wearer as the kurikata allows it to be. A kurikata is usually about three and a half inches from the mouth of the saya which means that in practice the tsuba is at least that distance away from abraiding with the hakama. Given that whilst wearing the sword a samurai would invariably walk with his left hand holding the exposed part of the saya and his thumb resting in a slightly hooked position over the upper ege of the tsuba, (The reason why so many kozuka and kogai are very worn), then the tsuba itself would not be in close proximity to enough of his clothing to account for significant wear on an iron tsuba, even over many hundreds of years of constant use by successive owners.

As Ford has stated.

I've always been a bit hesitant to take the opinion of tsuba experts as gospel myself. One should always ask;" how do you know that?" In my experience of tsuba experts the view from their armchairs is somewhat limited.

This would be particularly true of one who has never worn a sword or seen one worn other than in a photograph.

 

Sorry... but I just cant see how an iron tsuba could be significantly worn, at least enough to expose the bones by the simple expedient of abrasion caused by clothing. :D

[Surfson]

I'm sorry but this notion simply doesn't stand up to even superficial scrutiny. To allow that it may be a possibility requires far too many other aspects to be ignored as inconvenient.

 

I'm sure that you and many of the NMB members have been known to rub on an iron tsuba with a simple piece of cotton cloth and know that if you do it long enough you can smooth the surface and develop a patina. I realize that rust is softer than the iron, but I don't think that it requires a great deal of suspension of disbelief to think that silk can wear down a tsuba over hundreds of years.

 

We'll just have to do some experiments. Do you think that if you put an iron tsuba on a buffing wheel with soft buffing material of the hardness of a kimono that you could wear the mimi down two millimeters? If you are willing to wager, I think that it will, in fairly short order. Of course each minute of rotation of the wheel may be the equivalent of a week's wear, but we certainly can't do the experiment over 500 years using a kimono.....

 

As to the face of the tsuba that you mention, I'm not suggesting that all irregularities on the face or rim of a tsuba are from wear.

[Henry Wilson]

I don't think that it requires a great deal of suspension of disbelief to think that silk can wear down a tsuba over hundreds of years.

 

I find it hard to believe because:

*silk is not very strong and wears out quite quickly. It is not that abrasive. Rubbing a tsuba with a cotton cloth is different to wear produced by wearing it.

*Just because a tsuba is about 500 years old does not mean it has been worn 24 hours a day, 7 days a week on a sword and held against silk all the time and rubbed. Tsuba went in and out of fashion a lot and could have just of likely been stored for 200 years in a drawer as been worn.

 

Just some armchair thoughts

[sanjuro]

A couple of thoughts why this discussion in its present vein is destined to go nowhere:

 

1. A buffing wheel can hardly approximate the light touch of silk or even cotton over a period of time. There is no way it can be controlled as an experiment since the pressure against a buffing wheel required to wear the iron is greater than the pressure exerted by any material that is merely brushing the surface of the iron. Therein lies the invalidity of this entire 'wear by clothing' argument.

2. Only an idiot would subject a perfectly good tsuba (particularly one with tekkotsu),to this kind of treatment in order to prove or disprove the 'wear factor'. In this respect I suspect no one on the NMB would offer up a tsuba for the dubious joy of seeing it fundamentally destroyed, to no apparent gain