Tekkotsu

[kissakai]

Hi

Attached to another NMB post was a question about tekkotsu and searching the NMB this has not been covered in a single post

If we state that it is harder iron 'pieces' and they are of differing shapes then leave it at that

What I would really want to see is close up images of tokketsu and the schools which were well known for this aspect of their tsuba

I'll add some of my tsuba images later

George, do you have any examples as your images are incredible?

 

 

Grev

 

[ggil]

Just took these pics at the Christmas meeting. the owner of these 2 pieces knows the school or probably has NBTHK origami if you want me to look that up. I should’ve paid attention. One shows more linear bones and one is more random. Totally different forging, I guess.

[rkg]

I just got a super-bony one...  I'm actually not sure where it should be "binned" - I'd probably go with oh-no, but what do I know..  you actually really need 360 image sets, so here they are:

 

http://www.rkgphotos.com/facebook_stuff/temp_goose_tsuba_360/goose_sado_front/goose_sado_front.html

http://www.rkgphotos.com/facebook_stuff/temp_goose_tsuba_360/goose_sado_back/goose_sado_back.html

http://www.rkgphotos.com/facebook_stuff/temp_goose_tsuba_360/goose_sado_edge/goose_sado_edge.html

 

Enjoy,

rkg

(Richard George)

 

[kissakai]

Wonderful - More please

[ROKUJURO]

Grev,

what if we stated that we don't know for sure or what if it is not 'hard iron' (= steel)? There is no research done in this field, and technically it does not make sense to me, even if all experts have similar conjectures. I hope to be able to clear this up in the near future, but I might need some help.  

It is a difficult subject and similar to the problem of Damascus steel. Everybody seems to know that Damascus steel is made from layers of hard and soft steel, but that is simply not true. 

 

.....If we state that it is harder iron 'pieces' and they are of differing shapes then leave it at that.....

[Curran]

attached

[kissakai]

Hi Jean

I tried ti imply that I was only looking for images.

Often a discussion is easily distracted and this is why I've tried to keep it black and white

There may be images when an image is thought to contain tekkotsu but it may be a wrong assumption

This will help me when looking for tekkotsu

 

 

Grev

[lonely panet]

I have a link with abit about this on my home PC. I'll post the link when I get home from work

[FlorianB]

Bad shots, but sufficient:

 

 

In this case very prominent tekkotsu.

 

Florian

[JohnTo]

This was one of my first serious tsuba purchases (RB Caldwell collection, 1994), a tosho tsuba that typified 'bones' to me at the time.  It still provides a pleasurable sensation if I run my finger over it.  I can understand why the Japanese find it so exciting.

 

Interestingly the tekkotsu is only at the top and bottom of the tsuba.  I assume that it must have something to do with the way that the iron was folded and the bones squeezed out during forging.

 

Best regards, John

[Bazza]

I wonder if they don't simply "grow".  I have something to write up about some iron lumps I found on an old trailer coupling that might illuminate "something".  Give me time - sighhhh.

 

Barry "Gunnadoo" Thomas.

[ROKUJURO]

.....Interestingly the tekkotsu is only at the top and bottom of the tsuba.  I assume that it must have something to do with the way that the iron was folded and the bones squeezed out during forging.....

Hi John,

 

that is really a pleasant TSUBA in TOSHO style!

 

Interestingly, KO-TOSHO and KO-KACHUSHI TSUBA are not known to show TEKKOTSU, as far as I know. But you are of course right that the appearance of the 'bones' has to do with the way the inhomogenous iron was forged. 

 

A fact is that in forging layered material, not the 'hard' (= steel) particles are pressed out but the soft, ductile iron. This is stuff to think about, I feel....    

[CSM101]

Hope, you can see it.

 

 

Uwe G.

[ROKUJURO]

Yes, thank you! A good example! Now I need a piece of it for testing. Do you have a metal hacksaw?

[lonely panet]

http://www.ksky.ne.jp/~sumie99/tekkotsu.html

 

 

I cant find the link I was looking for at the moment. will this help. sasano's books will help

[Alan Morton]

For the main part I thought we were looking in these

fine pieces Bones  in the iron and not Tekkotsu, am I wrong?

which I've always seen as a mottling in the surface of the tsuba.

Im also amazed at what RKG does

 

Alan.

[FlorianB]

Sometimes on corroded pieces it becomes difficult to distinguish in between tekkotsu and coincidental structures produced by rusting.


Florian

[Hoshi]

I don't understand the appeal of this.

 

Is it the wabi-sabi aesthethics of having irregularities which evoke decay? Are these the effects of corrosion over time due to the unevenness of impurities in the steel? Are these hammered into place by the maker? It seems possible to make to 'make bones' with a file and a chisel. I know that bones are used to judge cast from carved work, but with enough effort it should be possible to recreate these. 

[kissakai]

Hi

Thanks for your images.

Sorry to be a pain but the creation or appreciation etc were not meant to be part of this post as this is best left forthcomming research

All I was after was images.

With so many tsuba our collections there must be more examples. Currently there are less than a dozen examples here

I'm going to sit down today and go through my tsuba for examples that I will post later

 

 

Grev

[rkg]

Too late to edit my last post - here are some more images of the tsuba I posted:

 

 

Best,

rkg

(Richard George)

[ROKUJURO]

Richard,

very good photos of a very pleasant TSUBA! Although it is a bit small, it is very desirable!

[FlorianB]

Chris,

Several pictures above (including mine) show distinct tekkotsu, but there are also Tsuba with a more restraint tekkotsu which could be recognized only by a closer look. Often tekkotsu has been abraded to get a smooth rim.
What I tried to express was that traces of corrosion could be mistaken for tekkotsu so in this cases a detailed examination is necessary.

Tekkotsu is first of all a result of production and could hint to certain schools/styles. It is also appreciated as an aesthetic trait.
Black rust (patina) on the other hand is part of certain aesthetic ideals i. e. wabi-sabi, too. But don’t mix up rusted tsuba with aesthetics generally - sometimes they are simply junk.

Florian

[JohnTo]

Hi Grev,

So, you want photos of bones.  They are elusive little devils to photograph.  Well there seem to be different opinions of what bones are and how they are formed, so I’ll try to see what I have got amongst my tsuba.  Lets start with another example of ‘dinosaur bones’, big lumps of iron poking out of the rim.  There is also a 3x5 mm lump sticking up on the left side of the plate near the rim (see pic 316)

This tsuba is a 19^th C example in perfect condition with no rust to hide the features.  It is signed and dated ‘Nobuie no katachi o motte Myochin Kuninao saku’ (made in the style of Nobuie by Myochin Kuninao) and ‘Koka sannen uma shigatsu bi’ (Koka third year of the horse [1846], fourth month, a day).  It has some lumps and bumps around the rim, but they look a bit contrived to me.  It is, after all, a copy.  Maybe Kuninao deliberately added lumps with skilful application of the hammer rather than trying to include real tekkotsu.  Difficult to tell, but as there is always someone on NMB who is quick to point out faking, I’ll jump in first with the suggestion.

I bought this tsuba at the same auction where a ‘genuine Nobuie’, with NBTHK Hozon was up for sale at £15-18K (unsold).  This was reported to have granular tekkotsu in the rim.  I looked hard but could not see any.

Best regards, John

(just a guy making observations, asking questions, trying to learn)

[Hoshi]

Thanks Florian. 

 

I am still confused. 

 

If 'bones' aren't made from: differential corrosion or hammering/chisel work, where do they come from? I don't see a third option. Does someone have a texbook photo of Tekkotsu that Tsuba expert agree that they are masterful and beautiful? 

[ROKUJURO]

Chris,

as this thread is meant to deal with just the images of TEKKOTSU I will send you a PM.

[JohnTo]

Hi Grev,

Maybe more bones for you, but now for something completely different.  I have seen tekkotsu described as small pieces of hard iron poking out of a soft matrix and as small pieces of soft iron poking out of a hard matrix.  What makes these pieces stand out from the bulk matrix is also subject to different opinions; forging process, rubbing against clothing or with sweaty hands.  These two examples seem to have been made by etching the surface causing one of the iron components to dissolve faster than the other leaving bones.  Are they tekkotsu?  I’ll leave that for more expert NMB  guys to comment.

The first example is a simple tosho tsuba (9.2 cm dia), nicely forged with a goishi gata plate.  The odd feature of this tsuba is the ‘toad skin’ surface (on both sides).  It almost looks like it has been decorated with a nanako punch.  I assume that it has been etched with acid to reveal the small round lumps of a different iron to the bulk material.  I have never seen another example of this finish.  Not a great tsuba, but interesting and I’m really quite fond of it.

The next example is a Heianjo/Kaga Yoshiro brass inlay tsuba.  The iron surface of this also seems to have been etched.  This time the ‘tekkotsu’ is granular.  The rim is also slightly granular.

Neither of these examples have any significant rust and both have a shine to the ji, possibly from a thin film of lacquer.  Of course I cannot tell if the little bumps are a different iron from the main body, but if they are, I guess they can be classed as ‘tekkotsu’, by definition.

 Best regards, John

(just a guy making observations, asking questions, trying to learn)

[JohnTo]

Hi Grev,

More bones.  Not very spectacular, just small granules on the rim.  The tsuba was catalogued as Kyo sukashi, but I would lean to Owari.

Best regards, John

(just a guy making observations, asking questions, trying to learn)

[ROKUJURO]

John,

you have a PM.

[FlorianB]

Chris ,

please refer to a textbook or the web but I try to explain it quickly: We know that raw material for Tsuba (iron/steel) consists of inhomogeneous carbon content. Tekkotsu (“iron bones”) is iron with higher carbon content and thus harder. While hammering the Tsuba, those higher carbon particles  (the harder particles) are pressed towards the outer rim. That's why tekkotsu could be found always there or at least near the rim. The appearance proof that the Tsuba was thoroughly forged.

 

Some schools appreciated tekkotsu as an aesthetic part of the tsuba (often found on pre-Edo pieces i.e. Ko-Shoami, Owari, Kanayama), others (most schools working throughout the Edo period) saw in tekkotsu obviously a disruption and grinded it down.
In how far tekkotsu was artifically produced I can’t tell but it seems possible especially in the revival pieces of the late Edo period.

Florian

[Ford Hallam]

Chris ,

 

please refer to a textbook or the web but I try to explain it quickly: We know that raw material for Tsuba (iron/steel) consists of inhomogeneous carbon content. Tekkotsu (“iron bones”) is iron with higher carbon content and thus harder. While hammering the Tsuba, those higher carbon particles  (the harder particles) are pressed towards the outer rim. That's why tekkotsu could be found always there or at least near the rim. The appearance proof that the Tsuba was thoroughly forged.

 

Some schools appreciated tekkotsu as an aesthetic part of the tsuba (often found on pre-Edo pieces i.e. Ko-Shoami, Owari, Kanayama), others (most schools working throughout the Edo period) saw in tekkotsu obviously a disruption and grinded it down.

In how far tekkotsu was artifically produced I can’t tell but it seems possible especially in the revival pieces of the late Edo period.

 

Florian

 

I'm afraid I have to disagree with most of this description.

 

We don't actually have any idea, pending some actual scientific analysis, what, if anything, the carbon content of any part of the so called tekkotsu structure might be.

 

Secondly, it only takes two, or three at most, compressions and folds of raw low carbon/to no carbon bloomery iron to create an essentially solid plate. There is no movement within that billet of alleged harder lumps migrating to the outer surfaces during this minimal forging process.

 

 I would add that while higher carbon might indicate a harder material it also means that it will more rapidly oxidise and rust. 

 

With regard to how the tekkotsu effect might be created:

 

My own, slightly tested theory, is that the plates made for tsuba were basically iron with virtually no carbon present. The very few analyses of ferrous tsuba that have been done show this to be so in most instances, and certainly where there is carbon detected it far too low to allow for the material to be hardened by heat treatment.  Further, most, if not practically all, ferrous tsuba are not hardened, as evidenced the apparent ease with which modifications were made and later decoration was added. Why bother using good steel if you don't need to heat treat it?

 

To harden the outer skin of a finished iron tsuba it can be packed in organic material, like bone or leather, and brought up to a high heat in a charcoal fire so that the iron can absorb carbon through diffusion. Basic case hardening. There are ways to ensure that the carbon is absorbed irregularly, like a clay coating for instance.

 

There is sufficient evidence to demonstrate that case hardening was known and practiced by the earliest ironworking cultures. And the process was used routinely by metal carvers in Japan when making their chisels. Kano Natsuo described the process in one of his workshop notebooks.

 

Subsequent oxidising and or rusting, or maybe even tumbling in a barrel of sand and small stones, would consume or abrade the lower carbon areas.