Cast Sword Fittings By Markus Sesko

[Thierry BERNARD]

Thank you Markus for this very interresting article!!

 

http://markussesko.com/2016/01/20/cast-sword-fittings/

[Miura]

Thanks so much for this post. Im happy that Markus wrote this article.

 

I wrote extensively on early cast iron tsuba on another message board back in 2012.  But because certain members were so vehemently opposed to the idea. The responses became almost vulgar and derogatory because the subject had been "discussed and closed" on the nihonto message board already.  I have not posted related to tosogu since then because the topic of cast iron tsuba and cast sword fittings seemed to enrage people.  So much so that people were afraid to contribute or come to my defence.  Im not sure why the notion upsets people because cast pieces are not inferior. There was cast armor as well.  

 

The addition of the video to the article I find to be amusing. 

 

Here is cast iron tsuba and sand tubes that I purchased back in 2008 from a construction site in NARA where they were discovered.  Perhaps even the construction site that lead to the excavation. I just know when and how I purchased them. Henry Wilson is the only person I have shown them to.

 

Andrew Mancabelli

[Gordon Sanders]

I think all in all we have to realize that being "lazy" is also being smart. Yes they were/are artists and craftsman, however they also needed to produce quantity at some points. Take Andy Warhol - he was criticized and at the same time admired

 

After 400 years , have we changed that much?

[Ford Hallam]

Andy,

 

I'm sorry your attempt at furthering your hypothesis was treated so harshly elsewhere and I'm glad I wasn't directly involved in such vulgar discussions....some people.

 

I'll offer some observations on this new find but would like first to point out that finding evidence of possible brass casting in no way supports you assertions regarding cast iron/steel tsuba. There is very little real correlation in the two technologies when we come down to the actual details of the practice. For me the biggest issue with the iron tsuba you suggest was cast is the clear appearance of layering in the edge. But a little scientific examination would easily establish how that artefact was made, cast metal and wrought iron are as different as chalk and cheese. It is a little problematic that the finds you bought are without any firm provenance fixing their date.

 

 

As far as the evidence you presented back in 2012 here and the snapshot you've just posted all all I can say is that the items are far from clear with respect to what they mean. Crucibles and tuyere in themselves are not uncommon. We expect to see them in any dig that finds evidence of metalworking. What then needs to be done are some fairly simple analyses. Traces of oxides and metals inside the crucibles can point to what was melted in them, for example.  Have the results of such basic tests been published? on the crucible you have or the ones more recently found in Nara?

 

Another test would be to establish the composition of the crucibles and to determine, by means of a microscopic examination of the structure of the clay body, what temperatures they were heated to. Clay does very specific things at fixed temperatures. If your crucible has been used to melt iron or steel we'd expect the clay body to be pretty well vitrified, that is, turned from earthenware to ceramic. Traces of iron oxies etc, in the crucible would also be supportive evidence.

 

Turning to the moulds found in Nara and your tusba blank. Neither exhibit clear evidence of either pouring flange/ spout nor runners. Runners are a network of small channels running from the impression of the object out to the edge of the mould. They are vital to allow the air inside the mould somewhere to escape through when molten metal is poured in, especially as molten metal tends to heat air up very quickly in enclosed spaces and heated air expands a lot. Therefore, the absence of runners in what appear to be a mould is problematic.

 

Apart from the matter of the runners finding evidence of brass casting is not a huge revelation though. Brass is very easy to cast. The real question is, where are all these cast brass tsuba and menuki? ( in the shipwreck of the San Diego, perhaps) But have the moulds been tested to see if the inner surfaces bare any traces of brass having been cast in them? I remain sceptical about whether these are in fact casting moulds until more detail is published. And, even if these do turn out to be casting moulds for brass this is only that, evidence for brass casting. Which was introduced by Korean craftsmen in the 8th century.

 

Metallic zinc was available from China only in the last few decades of the 17th century. Prior to that zinc was introduced to copper melts to make brass by means of adding crushed calamine, zinc ore. This process, called cementation, was used by the Greeks and the Romans more than 2500 years ago and the technology was in widespread use in Asia more than 1000 years ago. Cementation brass has a limit to the amount of zinc it can absorb and hold before it burns out. To get the maximum amount into the brass takes repeated melts. The point of diminishing returns is about 15%. There is another marker that accurately differentiates cementation brass from brass made with metallic zinc and that's the relative concentration of trace cadmium. So these details can firmly establish the date of the brass that was found in Nara. I assume at some stage these details will be established.  Metallic zinc wasn't produced in Japan until the early 20th century.

 

I hope I've at least provided a little context and more detail for our members to consider when contemplating these new finds. If it does turn out that these Nara finds are solid evidence of cast brass tsuba and menuki there still is a big leap to make from that point to then extrapolate that therefore casting of other non-ferrous fittings was commonplace in the Edo period. But that's a whole other book that would have to examine a mountain of other evidence.

 

regards all,

 

Ford

[Miura]

Thanks Ford. Not sure if that was an apology or...   Anyway  Ill post more at some point in a private forum. I don't have all the time in the world these days to engage in the discussion further as I am a working man. My apologies.  I will invite anybody to visit the museum exhibitions throughout Japan that have answered many of the questions you posed though. Thanks all and have a closer look at those iron tsuba of yours.

 

Andrew Mancabelli

[ROKUJURO]

Andrew,

I do not believe that we see a TSUBA on your photo. Casting techniques make only sense if the product is very close to the desired item, and in this case, a lot of factors let me believe that it was not meant to be a TSUBA.

In addition to what Ford explained so competently, I may add that melting iron not only requires furnace temperatures of significantly above 1.583°C, which is only attainable with technologies that were developed later, but as Ford points out, crucibles and molds have to withstand these temperatures as well. Clay as the standard material for handling soft metals like copper and bronze may be sufficient up to 1.250°C, but only special refractories can withstand considerably higher temperatures. One has to remember that medieval Asian stoneware and porcelain ceramics were fired in kilns like ANAGAMA up to temperatures of almost 1.300°C, and this was the limit at these times.

Another point is that cast iron TSUBA are brittle and not useful as part of a weapon. This has been mentioned here before.

Eventually, casting techniques in early times were not a means to produce large numbers of identical objects. The items were one of a kind and required a lot of finish work.  

[Markus]

Thank you for dropping in Ford!

 

I too think that this find should not be linked in any way to iron or possible iron casting. Another line of thoughts of mine was if this workshop was nothing more than a production site for samples, commissioned by sword dealers (maybe based in Kyoto or in downtown Nara as most logical suggestions) to show their customers what could be done in iron, e.g. as sukashi. So you have a wide variety of cast brass sukashi-tsuba in your shop and if your customer has decided to have a certain piece/style to go with his koshirae, you forward the cheap cast brass sample to the actual tsuba maker and things go from there. The same could go for menuki. This would explain the lack of actual extant cast fittings. And later on when everything, i.e. entire sword production lines were transferred to Edo, these local cast workshops were discontinued. Maybe by then also the entire chain of commissioning/selling swords had changed what would explain that we don't find such cast workshops in greater number (maybe rubbings/drawings were just more economical).

 

Very interesting but as said at the bottom of my write up, its hard to develop a proper theory on just that one find.

[ROKUJURO]

Jean,

 

Im sorry, there was no mould in association as far as I know. 

........

Andrew,

 

my fault! Sorry for that! I do not recognize the item on the lower right side of your photo as TSUBA.

[Brian Ayres]

It looks to me more like a pre-form forged tsuba. It was slit for the nakago but not drifted to size. And when it was being forged out a lobe of the tsuba fell off and the tsuba was unceremoniously tossed in the slag heap with the molds from other projects at the sight.

Or, it's a tsuba that was tossed in a fire that was hot and oxidizing....It looks like melted glass that you find in older campsites in the mountains.

[ROKUJURO]

Brian,

in most cases NAKAGO-ANA are not drifted open to size as this would cause the SEPPA-DAI to bulge. As far as I know, traditionally made openings of forged TSUBA were chiselled to size. Later in EDO times, a fine saw was used with a thin wire, oil, and diamond dust as abrasive.

[C0D]

I just bought a tsuba that might give some fuel to the topic, it appears a copper based alloy (bronze maybe?) tsuba that shows evident signes of casting inside the petals sukashi, but inside the nakago and kozuka ana is smooth as being cut.
Thickness is quite thin, 3mm, and overall dimension is around 60mm 
In my opinion is a genuine Muromachi piece.

[IanB]

 I have long advocated the theory that iron sukashi tsuba were cast and decarburised (like cast iron kettles) to be worked up to a finished state once malleable - a proposition based on the total absence of piercing saws or similar tools being available for making the multiple complex piercings that are a feature of so many sukashi tsuba. Whilst this find does not substantiate this entirely, the evidence being for non-ferrous tsuba making, it goes some way that the idea may have validity.

 

There is one area in which these non-ferrrous chrysanthemum form tsuba were employed and that was for trade-staff weapons. Those I have seen were of naginata type and all were fitted with these soft metal sukashi chrysanthemoid tsuba, sometimes gilded and sometimes blackened to look like shakudo. The weapons in question are fitted with what appear to be regular naginata blades, of good shape, with well cut grooves, but in fact of soft iron and with only short weak tangs securely riveted into the shaft. The shafts themselves are black lacquered, often round in section not oval, with a complex of gilded copper fittings under the tsuba decorated with tendrils and foliage on a nanako ground. It is recorded that the red-seal ships of Hideyoshi traded large numbers of staff weapons in SE Asia. The Rijksmuseum in Amsterdam has a display rack of weapons from that area with two of these 'naginata' ( NG-NM- 6089-A, 6090-A) and two 'yari'. The same display has what appear to be katana (NG-NM 6097-C, 6097-B ), again with these sukashi tsuba, this time gilded, that have blades without mekugi ana. Clearly the Japanese did not ship real weapons but replicas.

 

The same article also illustrates another topic I advocated and which again proved controversial, that of the so-called Satsuma Rebellion tsuka bindings. NO, they were made for issue to ashigaru as indicated by the katana in the above article.

[Ford Hallam]

- a proposition based on the total absence of piercing saws or similar tools being available for making the multiple complex piercings that are a feature of so many sukashi tsuba. 

 

 

I think it can be reasonably demonstrated that the processes employed in the production of pierced work prior to the introduction of piercing saws in the late 19th century were a combination of drilling, chiselling and filing.