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Mekugiana - Drilled or Punched?


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I have been searching the forums about punching vs drilling and how to tell. The best I have come up with is that it's not the shape that's the true indicator, but the pillowing of metal where the bit emerges from the steel. However, I can't seem to find any good comparative examples. When did drilling first become a standard practice? And how could one definitively tell if a mekugiana is drilled or punched?

 

Here is what I am looking at: 20210504_223051.thumb.jpg.2a12ba75fd56ce3814adb5a2b22edf91.jpg20210504_223758.thumb.jpg.d44b5b08eebf1b4ea7029eb6ce8806d1.jpg

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Punching was done alternating from both sides, so there’s no outwards facing exit “pillow”, but usually a kind of “step” in the middle of the hole.

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Yours is punched, for sure. I assume very sharp edges of the whole, uniform size on both sides would potentially speak of drilled but I have read that uniform looking ends do not necessarily mean drilled.

 

Cheers

 

John

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Neil, 

 

Quote

And how could one definitively tell if a mekugiana is drilled or punched?

 

IMHO, it is often impossible to know if a mekugi ana has been punched or drilled and I think we should let the mekugi-ana aside when we make a kantei.

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8 hours ago, Bugyotsuji said:

.......What kind of punch would they have used? A tagane and a big metal hammer, onto a... wooden surface?

Piers,

Western anvils have a pritchel hole which you can use. There are also tools that go into the hardie hole that have smaller or bigger holes so you can punch through. Japanese swordsmiths may have similar tools. The punches (or TAGANE) are conically shaped and mostly have a blunt tip. Holes are usually drifted from both sides and the excess filed flat, so there are no 'cushions'. The same applies to drilled MEKUGI-ANA: the 'cushions' have to be filed away, otherwise there would be an obstacle for the TSUKA. 

Jacques is correct when he says that it is often difficult or even impossible to differentiate between a drilled and a punched MEKUGI-ANA. But on closer inspection and a magnifying glass, you may often see a tiny difference in the respective hole, just as Guido mentions.

I have seen drilled holed with a "step" as a result of unprecise drilling from both sides - the Japanese did not have power tools, and drilling steel was probably not at all easier than punching a hole in a red-hot NAKAGO. The advantage of drilling was that it could be done at a much later stage of finish, and I think in later times it was probably often done by the TSUKAMAKI-SHI for easier adapting of the TSUKA. 

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Jean,

 

You mention punching thru a "red hot Nakago", I thought the Tsukamaki-Shi installed the Mekugi-Ana hole.

 

 So your saying the Tsukamaki-Shi re-heated the Nakago?

 

Would not re-heating the Nakago to a red hot state, damage the temper on the blade?

 

Mark

 

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I'm going to pose what I hope isn't too stupid a question -

 

I think I read in one of Darcy's articles or posts that the spidery mei on Muromachi Bizen swords was to avoid work-hardening the tang and adversely affecting the sword's durability. Would that not be an issue with punching the mekugi ana also? I've not read anything about it but do smiths put the mekugi ana in a heated tang prior to final hardening and tempering?

 

Sorry that's two questions. Hope I haven't doubled down on the stupid. :freak:

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I wonder if the swordsmiths did not already drill the mekugi-ana during the koto era, it is known that some mekugi-ana were made to adapt a tsuka or a new koshirae and heating a nakago would have been risked.

 

The invention of the drill is not recent.

 

https://www.britannica.com/technology/hand-tool/Drilling-and-boring-tools 

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2 hours ago, Shugyosha said:

I'm going to pose what I hope isn't too stupid a question -

 

I think I read in one of Darcy's articles or posts that the spidery mei on Muromachi Bizen swords was to avoid work-hardening the tang and adversely affecting the sword's durability. Would that not be an issue with punching the mekugi ana also? I've not read anything about it but do smiths put the mekugi ana in a heated tang prior to final hardening and tempering?

 

Sorry that's two questions. Hope I haven't doubled down on the stupid. :freak:

 

Hi John, thats a good point, as only ever watched vids of swords made with drilled ana.

 

Makes sense to put a punched hole in before any hardening. 

 

From what i can gather, heating the steel, punching and letting it cool naturally should not make it brittle. Gets into all this blacksmith stuff again with terms like "normalising" etc .

 

Ps, i always thought the "spidery mei" was an indicator of slap dash kazu-uchimono:laughing:

 

 

 

 

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I think the 'Hot punching' video from the Black Bear forge that Alex linked to can answer a lot of questions. Hot punching is easy and fast, and it is little work for a swordsmith while he is still at work on a blade just before YAKI-IRE (quenching).

I do not know when drilling steel came into use in Japan, but I have seen pump drills being used by TOSOGU artists on soft metals. One has to imagine that spiral drill bits are a late invention even in Europe, even if one has been found to be of Roman origin (excellent article provided by Jacques). I have a big collection of tools from the European pre-industrial period, and from that I learned that drilling was always a very slow process with little work progress. Augers (already used by the Vikings in ship building) could be used for wood, but not for metal.  

So, to answer Mark's question, I do not believe that the TSUKAMAKI craftsmen used heat on a NAKAGO. On the other hand, a skilled smith could make transformations on the NAKAGO like ORIKAESHI-MEI without damaging the YAKIBA. This is not difficult, if you cool the blade carefully with a wet rag.

John's post about 'work-hardening' of the NAKAGO is interesting, but from the metallurgy side, there is no such problem. 'Work-hardening' needs high energy input into the workpiece, and the result depends a lot on the alloy used. A relevant manganese content in a workpiece can indeed lead to a superficial hardening when you pre-punch an intended drill hole. That will cause problems for a drill to penetrate.  Alloys like these are well suited for the production of rails, anvils, and special tools.

Chiseling a MEI would not cause a noticeable work-hardening surface in a NAKAGO (made of non-hardened pure carbon steel), and there is no danger that such a sword may fail in combat.

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