Hi folks! + question on fatal flaws

[steve rb]

Hi there folks, great board have been over at SFI for a while but there seems a fair bit more activity over here.

 

First post - and it's a question on fatal vs non-fatal flaws. I've seen the usual lists but I have a couple that I can't make up my mind on. The first is a crack in the kissaki that is only visible on one side. I can feel it with a nail, I can't see it on the reverse. It resembles a karasuguchi, BUT, if I understood those correctly, it is where the crack is pointing inwards across the hamon in 'hagire style' and cannot be polished out. With this crack, it could be polished out in the same way as a chip. The rest of the blade is great and it is due to go in for a polish - what do you think?

 

The second flaw is a ware just between the hamon-ji boundry. However, this is deep and is just about noticeable from the other side (very thin blade, without any trace of niku). Is this fatal? I could find not comments regarding such a fukuru / ware.

 

Pics attached and help appreciated!

Steve

[Ford Hallam]

Hi Steve,

 

I'd suggest that if the blade has a flaw that is visible from both sides, indicating that it extends right through the blade, it's a beyond tired, it's absolutely knackered . You say that it is a very thin blade, it may be that it has simply had a lot of polishes in its existence and that the shin-gane it now peeping through. I don't think there is anything to be done about it really, polishing will most likely only reveal more of the same. Sorry

 

Others may have a different take on it though.

 

cheers, Ford

[steve rb]

I suspect it has had a deep polish to remove something. The blade is a gendaito and therefore I doubt it has seen too much wear unaided. The blade is devoid of any trace of niku but is otherwise fairly wide and healthy, no core steel showing, hada intact. Just this nasty deep ware.

So, do you think it is fatal? I couldn't find any reference to a flaw that appears on both sides of the blade.

 

What about the other blade and that 'crows beak' style flaw? Only visible from one side and could be polished out....?

 

Thanks for your help.

Steve

[Brian]

Steve,

2 Difficult ones there. I don't think that either is "fatal" in the common terms we normally use. I think the kissaki flaw is a bad fold/ware that is showing up quite badly. Difficult to polish the whole thing out as it looks quite deep near the yokote, but not cutting through the hamon. It will be easier to evaluate during polish to see how deep and serious it is.

The other one doesn't look to me to go right through the blade. Perhaps it is co-incidence that they are in the same place? Looks like a bad area of forging..maybe carbon pocket or fukure? That might cause it to look like it is right through. I don't think it is fatal though, just a bit nasty.

Fatal flaws would have to interfere with the structural integrity of the blade when being used. None of these 2 cut through the hamon to cause a catastrophic failure, so I would call them bad flaws, but not fatal.

Just my opinion though...the more knowledgeable members might disagree.

 

Brian

[nagamaki - Franco]

Greetings,

 

The situation with ware and similar flaws which appear inside the hamon, is that the hardened steel does not give the polisher the option of pushing surrounding metal into the area to fill in and masque the flaw.

 

Franco