A question of Nie

[paulb]

Dear All

I would appreciate some opinions regarding the presence or lack of it of nie on an older blade.

Recently I have been looking at a tanto which I believe dates from late kamakura to early Nambokucho. It is single piece construction (I am assuming this because despite it's hard life there is no sign of core steel and the hada remains clear and beautiful)

The blade shows all of the characteristics of the school concerned except for the amount of nie. This particular group is noted for the amount and quality of the ji-nie and ko-nie in the hamon. While this blade has both I would not describe them as prolific.

Question:

If we accept that nie is created by the prolonged application of heat to higher carbon steel within the composite of the blade it seems reasonable to assume that it is most visible on the blades surface. Therefore as a blade is polished the nie diminishes as more of the surface is removed. In a single piece construction blade is it possible that repeated polishing can reduce or even remove nie without obviously effecting the integrity of the hada.

If this is the case it would explain why this particular work is lacking nie but still shows all the other characteristics of the school

Of course this may just be wishful thinking it could equally be a copy by a lesser school using inferior material.

I would be interested in peoples thoughts

Regards

Paul

[Alex A]

Hi Paul, if repeated polishes diminished nie, it is not likely you would see a trend like this on all Kamakura blades?. In other words, all blades by the same school would be the same, depending on a similar amount of polishing, just a novice thought.

[paulb]

Hi Alex,

Yes you are right, but it depends a lot on what has happened in the period in between forging and now. The number of polishes, how the sword was used or stored. In reality we don't know what a kamakura period blade looked like new so we have to speculate. Luckily some have been treasured more or less since they were made so are well preserved, which makes the task easier.

I think what I am getting at is I am tending to attribute this piece to a branch school copy because of the lack of nie. Before I jump to that conclusion I ought to think of other reasons the nie is lacking. If a copyist has the skill to add all the other activity (which are nie based) then the inclusion of ji-nie should not present a problem so why isn't it there?

Just trying to work through potential attributions and as always the more answers I come up with the more new questions appear

[Alex A]

One possibility that springs to mind is consistency. Is it possible this could be due to the carbon content of the jigane at the time the blade was forged?. A blade made by the school in question, but lacking their typical nie quality.

[Brian]

I cannot see how nie crystals that form on the surface of the steel would be able to carry through all the way down through the steel. The hamon/hardened edge maybe. But nie...especailyl ko-nie?

So I would expect nie to get less prominent as the steel is polished away. Maybe I am wrong, but this seems logical to me. Also, tanto were mostly of monocore construction, not unusual there.

 

Brian

[cabowen]

First, it is my understanding that all other things equal, nie is formed when the quench is done with the blade at a higher temperature. I believe that carbon content also has an influence on nie formation.

 

It is entirely possible that for some reason your blade was simply quenched at a slightly lower temperature or that perhaps the carbon content of the steel is lower. It is a fine balance.

 

As for polishing through the nie, I believe this is possible as concerns ji-nie as they do not penetrate through the blade. The nie at the habuchi may change as well with polishing at the upper boundary of the habuchi but those at the lower edge may not change much if at all as the ha is through hardened.

[nagamaki - Franco]

Hi Paul, if nie were supposed to be present, then while there may be areas of weakness in the nie due to being polished down, I would have a very difficult time believing that it would be absent for the entire length. Somewhere along the hamon there should remain evidence of having been there and the total lack there of suggests (at least to myself) to seek answers elsewhere.

 

Merry Christmas All,

 

Franco

[Mikevorn]

Could a re-temper have this result?

[paulb]

Hi Franco,

A merry Christmas to you too.

I am sorry I may have not been clear. There is nie present in both hada and hamon, there is just not as much as I would expect to see based on the way the work of the school is described. There is also a lot of other activity there such as chickei in the hada and inazuma, sunagashi within the hamon.

Mike

I think re-tempering will if anything create large and ugly patches of nie rather than make them disappear, but of course it will depend the temperature the blade is taken to through the process. There is certainly no other indicator of re-tempering on it but it is something to consider, if only to eliminate it as a possibilty.

Regards

Paul

[runagmc]

I agree that particles of nie can be polished away, and new particles of nie can become revealed as a sword is polished down. In the same way, large choji activities along the hamon can become tobiyaki after much polishing, etc...

 

The more times the sword is polished, the more diffuse the nioi-guchi will become, and the amount of nie/nioi particles will decrease in general.

 

It is difficult to make meaningful assumptions on a sword which is polished way down, because we can't know (at laest without old pics) how much the sword has changed through polish.

 

IMO...

[ROKUJURO]

.....Question: If we accept that nie is created by the prolonged application of heat to higher carbon steel within the composite of the blade it seems reasonable to assume that it is most visible on the blades surface......

Paul,

 

this assumption is not correct. It is not the prolonged application of heat (which would lead to form coarse crystals within the metal structure of the steel, causing a decrease of sharpness and strength) but it is higher temperature, as Chris pointed out correctly.

 

As far as we know, creating martensite in form of NIE and NIOI plus all the nice little structures of them (CHIKEI, INAZUMA, SUNAGASHI, a.s.o.) requires a fine balance of the carbon content in the steel (and it's distribution), the heating process and the quenching within a very limited range of temperatures. If one of these criteria is not met perfectly, the outcome may not be as expected. The superior mastership of the smiths of old times, their experience with making and processing the steel and doing the heat treatment, and of course the forming of a blade leads to a relative consistency in the appearence of the blades of one school.

 

Do we know if blades were destroyed when they did not fulfill the rquirements of the related school? I could imagine so, and also I could imagine that a blade with somewhat lesser inherent quality could slip through, especially when these drawbacks were only visible after a number of polishes.

 

It is probably like the paintings of a great master: Many of them are very good, but some may not match the highest level.

 

This is my understanding of the complex materia.