Weird Hamon, Possible Retemper?

[Hastur]

Hi, I am perplexed by the hamon on this one. the sellers pictures are not the best but it seems to by muneyaki? could it be a retemper and is there any way to positively identify that?

[ROKUJURO]

Hastur,

what makes you think it could be retempered/SAIHA? The pictures don't tell much, but it looks like HITATSURA in places. Better and detailed photos from above (not at an angle) might reveal what it really is. (ECHIZEN no JU KUNISHIGE)

[Hastur]

I'm not familiar with hitatsura bit looking at pictures it matches pretty well.

[Hastur]

Is it a common style from that Smith?

[Darcy]

Mizukage at the machi is a sign of tempering rather than retempering.

 

When you see mizukage in combination with suriage, you have conflicting information: the nakago tells you that the machi is not original, and the hamon tells you that the machi is original. So, that is where you end up with the conclusion of retempering.

 

Mizukage can be removed somewhat with hot copper and I think maybe the Hizen smiths did this, I don't know much about it but some other guys do.

 

In this case I don't think what you see is a sign of retempering. But I agree it looks weird. 

[Hastur]

Ya it's odd, is there any structural disadvantage for having the temper reach near the mune? I should put more research I to this style I'm used to a clear separation of hardened and soft style.

[Bazza]

The last picture suggests two things to me (1) that the clay simply fell off the blade there during yakiire, or (2) that the smith might have been attempting to create O-koshiba of the Kamakura period.  I have seen a Shinto/Shinshinto katana that had a very good representation of O-koshiba.

 

BaZZa.

[Hastur]

Would that be a fatal flaw if it was the clay option? It sounds serious.

[SwordGuyJoe]

No. Not fatal at all. Some view this as a "flaw" and some view it as an interesting hamon.

[Hastur]

Would a sword with this kind of tempering be brittle for lack of soft mune?

[ROKUJURO]

Brad,

to answer your question precisely, you have to know the construction of the blade. Imagine as an example that only the outer steel layers of the blade (KAWAGANE) contain enough carbon for hardening. In many cases, these layers may only be some tenth of a millimeter thick, while the flexible core steel (SHINGANE) may have 4 to 5 mm (just an average figure). In this case you will find only a small influence of the hardened part.

The old swordsmiths had a lot of experience, and they knew that their customers' lives depended on the reliability of their swords, so I believe that they took no risk. We know that some of the best blades were made with HITATSURA HAMON so I don't think they were more likely to break than other blades. 

[Hastur]

Sorry guys somone went and bought it ahead of me while the person I was in contact was away bummer I was dead set on buying it too.