Nakago Discoloration

[Hastur]

Hello! I noticed that the tang on this late war gunto has what looks like heat discoloration on the Nakago, I have only seen similar marks on Kai gunto Nakago before. Does anyone have any ideas on the reason for it? Reshaped Nakago perhaps? Also it is a bit hard to see but is anyone familiar with the makers signature as well?


Cheers guys!

[Stephen]

hard to tell thu all the shadows 

[Hastur]

Its the greenish blue line that runs about midway down. marks the difference between the "burnt" end and the regular colored part.

[Dave R]

 Probably related to the second mekugi-ana at the nakago-jiri. Either a heat treatment to soften the steel, or more likely a quick and dirty drill job that friction heated up the nakago there.

[Stephen]

Talking about reading the mei.

[Hastur]

Ah sorry about that, I'll try to get better pictures tonight.

[reeder]

No need for better pictures. The smith is Katsumasa, dated Showa 20 (1945).

[Stephen]

Well what if i wanted better pix Brandon????

[Hastur]

Don't worry pics will be incoming anyhow XD, it's in decent shape other than the odd polish (blade sharpness only starts about 4 inches past the habaki and it a plateau) before that. Thanks for the translation and discolor source guys!

[Bruce Pennington]

No need for better pictures. The smith is Katsumasa, dated Showa 20 (1945).

February 1945

[raaay]

Hi Brad

 

as mentioned it could be heat from drilling !

 

I have seen similar before when a sword has parted company with its original tsuka,  some " Idiot " heats the tang to  burn out the timber in a shallower replacement tsuka to make it fit the new tang ? not saying it is the case,

but I have seen it done you can normally tell it leaves a very strong smell of burning  in  the tsuka , and if your lucky it does not take out the Hamon with it.

[Stephen]

Id go with Daves first theory

 

 

 

" a heat treatment to soften the steel"

[Hastur]

Interesting, Would they soften the steel to reshape it usually? Would that severely weaken the steel in that area? The tsuka has no burnt smell whatsoever and seems to be fitted decently.

[Stephen]

So the drill wont burn up...

[Stephen]

KATSUMASA (勝正), Shōwa (昭和, 1926-1989), Gifu – “Katsumasa” (勝正), real name Kojima Shichi´emon (小島七右衛門), born October 20th 1892, he studied under Kaneyoshi (兼吉), worked as a guntō smith and died September 22nd 1947

 

could be your guy

[Dave R]

 To elaborate on what I think most likely. If a hole is drilled in steel without lubrication, in a hurry or with a blunt drill bit a lot of heat is generated by friction.Enough in fact to cause discolouration! Any or all of these scenarios fit in with late war production. 

[Hastur]

Pictures up! note the non sharpened first few inches of blade, not as crude as my field sharpened type 32 though. 

[Stephen]

Its called ubu ba, all swords were made that way, just lost with multiple sharpenings. 

[Hastur]

New term for me I'll have to research it thanks for the heads up. It's too bad scabbard fittings for this type are a pain to find. The only showato I have ever owned to show off the kissaki prominently anyhow, So it has its purpose.

[Bruce Pennington]

That is a beautiful blade Brad, congrats!

[Hastur]

Thanks it seems pretty good for such a late date. I would probably not trust the steel quality if it wasn't signed XD.

[Stegel]

I'm of the belief that the end of the tang has been heated, perhaps with an oxy/aceylene torch to get that much colour change.

To get that much heat generated using a blunt drill bit, well, they must have been drilling for half an hour just to penetrate 5-6mm???

[vajo]

The blade looks nice. About the coloration. Handle the nakago without gloves and in some years no one cares about the coloration. 

[Hastur]

Ya the coloration would suggest some serious heat was applied, interestingly more so on one side then another. Patina solves all problems on that note, true enough