Koa Isshin

[werner]

Hi,

 

Just wondered if all Koa Isshins were all made with the same blade length or were there variations such as custom made ones?

 

Regards,

 

Jock

[JamesH]

I have seen a koa isshin wakizashi in shirasaya, but someone snatched it up well before I was able to buy ... it all comes down to $$

 

 

James

[werner]

...thanks James...

 

I wonder if one could say that the production process to make a Koa Isshin is the same as producing a sanmai blade and then heat temper and water quench it? Am I mistaken here?

 

This brings me to the next question: Seeing the ever growing number of martial arts enthusiasts one wonders why nobody produces a modern "koa isshin" line...with reference to the past and its proven qualities that should be a brand / product that the market readily should take up....

 

Would be interested to see your thoughts on the points above guys...

 

Jock

[bluboxer]

Hello Jock,

it is my understanding that the Koa Isshin Mantetsu-to was produced by inserting a lower carbon rod (spring steel) into a higher carbon steel pipe and forge welding them together.This would be most similar to "makuri" construction rather than san mai.The high carbon "pipe" would comprise the jacket steel and was then differentially heat treated as per standard practice (coating with clay and quenching).

This was quite an engineering feat IMO.I would have liked to tour the factory and view the mechanical process for the manufacture of these blades also.

Google mantetsu-to as there are some interesting articles on the web.

[werner]

Hi Alan,

 

Thanks for the input...I'll google it now....

 

Jock

[David Flynn]

I have been lead to believe, that these swords are actually handmade. Some have Mokume hada, some Itame hada and some Nashiji hada. I have also been lead to believe, that the Numbers on the mune of the nakago are a reference number to the smith that made a particular sword. Alas, many theories abound.

[Kevin]

I have been lead to believe, that these swords are actually handmade.

 

Partially hand-forged. A few smiths taught the workforce. The company made especially pure sponge iron for swords, then turned it into carbon steel. I imagine the block was folded, hence the hada. Now if they followed the usual way of making seamless pipes, they'd have drilled a hole partially through the block (leaving the end for the kissaki closed), then forged or hot-rolled it down around a mandrel. Then a rod of carbon steel with a lower carbon content was inserted as core steel, the whole lot forge-welded together and forged into a sword, after which it was hardened in the traditional manner. BTW the term, in English, is not surprisingly 'pipe welding'. Some American smiths use it. The Chinese are apparently starting to do Koa Isshin repros. One I've seen was quite good quality. It may have used pipe-welding.

 

Kevin

[Christian Chaffee]

Hi Fellow sword enthusiasts, I saw this thread, and wanted to say I have a Koa Isshin Mantetsu wakizashi in shirasaya. It is in full polish, and is beautiful. It has nashiji hada, and sunigashi along a suguha yakiba, as well as big nie in the boshi. The nagasa is just over 21.5 inches. Any idea of fair market value? This thread is the only reference to a Koa Isshin wakizashi I can find. Thanks, Christian

[Bruno]

Hi Christian,

 

May you please post clear photos of your Mantetstu wakizashi? I have never seen one before.

 

Thanks in advance.

[Christian Chaffee]

Hi Bruno, I will get images posted early next week. Thanks, Christian

[Christian Chaffee]

Hi Bruno,

 

Did you get to see the images. I don't know if I properly posted them.

 

I will be putting this Koa Isshin wakizashi on eBay.

 

Thanks, Christian

[Bruno]

Sorry no visible photos that I can see! :D