What's "ouko"?

[Josh]

Not sure this is the right place to ask, but here goes.

 

Came across this tanto, and the signature caught my eye:

https://www.aoijapan.com/tanto-motte-ouko-hideaki-saku-fukushima-shi-zo-showa-3-nen-boshin-oki-hi1928/

 

以桜鋼秀明作 (Motte Ouko Hideaki Saku)

 

The kanji 櫻 used in the actual signature is an older form of 桜. Both mean sakura, and 鋼 means steel.

 

The only explanation provided on Aoi is "The Tanto is made of Ouko(special iron) Hideaki". So, what exactly is this 桜鋼 (ouko), or "sakura steel"? Any ideas, or might this just be something that only the smith and the person who commissioned the tanto would know about?

[Shugyosha]

Hi Josh,

 

Short answer is that I have no idea.

 

Occasionally types of steel or forging techniques get a mention in sword signatures and, as you suggest, it's perhaps reasonable to conclude that because it is noted on the tang, it was a custom order using superior quality material, perhaps where the smith had further refined the steel himself using a particular process.

 

If you don't get a better answer than this, maybe you could email Aoi and see if they know anything about it?

[John A Stuart]

There are kitchen knives that tout Sakura Steel. It is a molybdenum sfainless steel. John

[Ken-Hawaii]

Probably chrome-moly, then, as molybdenum is seldom used by itself in steel.

[ROKUJURO]

Perhaps SAKURA stands for 'bloomery' steel.....

[vajo]

Stainless steel? The blade looks like a showa-to 

Not really exciting in my eyes. What has Lindbergh to do with that Tanto? 

 

I have a Masataka which was forged 1972

In that year the Nishitetsu Lions baseball club, part of the NPB's Pacific League, is sold to the Fukuoka Baseball Corporation 

[Josh]

Jean... I like your answer the best

 

I'm pretty satisfied with the answer that it's a stainless steel, the smith was working at a steel producer at the time so it makes sense. Still, I'll email Aoi later today, see what they say. I'll post their response here.

 

Chris, I think I saw one on their site that was made 8n the same year as a terrible terrorist attack in Japan. I've gotta say, it didn't make me any more inclined to buy it!

[PNSSHOGUN]

Yes, sometimes the historical links are dubious at best with literally no relation to the sword whatsoever.

[ROKUJURO]

Josh,

it is certainly not a stainless steel as it then would not show HADA or HAMON. Stainless steel was invented in about 1910 and started to be available soon after. The first stainless steel alloys were not suitable for cutting tools.  

SAKURA could very well be a name for a special manufacture of steel (comparable to 'blue paper steel' or 'white paper steel'),  but I think it must have been close to TAMAHAGANE.

[vajo]

Jean i see some kai gunto with a nice hada and hamon made from a kind of stainless steel. I would not bet on. Btw on that sword a see less activity.

 

http://ohmura-study.net/212.html

Tsuruta San maybe can answer the question what ouko is.