ROKUJURO

Ah yes, thank you! I thought the link was for the rusty TSUBA! As I said, unfamiliar design and technique for me.

Lewis, the photo is not ideal to make a statement, but I would like to know what makes this TSUBA an OMORI school item. Is it signed or accompanied by papers? An unusual design in my eyes.

The HAMON follows the outline nicely; the front end does not look like reshaped to me. If it was made from a broken blade, I think it was a HIRAZUKURI one before. The long NAKAGO makes it look unbalanced as mentioned before. The pictures are not good enough for me to make a statement concerning the age, but the NAKAGO seems to have no patina, so this might indeed be an indication for a recent modification of an originally longer blade.

Patrick, you know that this is probably a cast TSUBA?

Haidar, TAMAHAGANE is produced in a range of different qualities. This is not intentional, but happens accidentally in the TATARA process. The basic material has low carbon content (around 0.3%), while some of the material is coming out of the TATARA as cast iron with more than 2% of carbon. The low-carbon TAMAHAGANE is mostly used for making SHINGANE, while cast iron is processed in OROSHIGANE furnaces to increase the carbon content of iron/steel. Other qualities are selected and sold on the basis of purity and hardness, but without material analysis. As Jacques stated, carbon content in the cutting edges of Japanese swords changed over time. One approach to find the optimum steel may be the fact that carbon content in steel has a peak at 0.78%. At that point, carbon is fully solved in the steel matrix without forming carbides. This leads to a very fine structure and very high hardness which can go up to HRC 67. A higher carbon content does not result in higher hardness. Before the upcoming scientific research in the industrial era, there was no knowledge about chemistry and metallurgy, but there was experience. Steel can be "felt" when working with it, and making small samples, hardening and tempering them, and watch how they 'behave' in bending or breaking tests tells a swordsmith all that is necessary to know.

M, please sign all posts with a first name plus an initial so we could address you politely. It is a rule here on NMB. Your own assessment is quite on the spot. While the blade looks authentic, It is probably a very late blade, maybe later than MEIJI JIDAI, and it is in bad condition. In addition to that, it has a very simple KOSHIRAE in my opinion. But all comes down to the price you paid. If it was really cheap, you could possibly recoup your money in a resale.

Avoiding grease or fatty substances on copper alloys will help prevent green corrosion.

So the answer to Steve's initial question would be "NO, we can't relate a MUMEI KANAYAMA TSUBA to a specific TSUBAKO". As we do not have names, I would like to ask if schools, workshops, ateliers or groups are known or their respective location in OWARI province?

Paris, that is INOME (猪目) Looks more like water droplets to me.

Bruno, the photo is not well focused, so may I ask if this TSUBA is cast? As you have it in hand, you might be able to see that clearly.

Haidar's question was, in principle, "Do you know any techniques that a swordsmith can do to reduce the damage when folding modern steel to make a KATANA?" I tried to answer to this. I do not think that ORANDA TETSU or NANBAN TETSU have to do with this, but taking up this subject, I would like to remind that European steel of these times (about 1600, plus/minus 100 years) was made in big quantities, but as a raw, impure material. It had to be treated with the OROSHIGANE process to make it suitable for sword making. And of course there were no secret ORANDA techniques to make this a superior steel other than what Europeans were used to do. This was basically the reduction of carbon as the steel was first produced as cast iron in the early blast-furnaces of the time. And finally, as mentioned by Eric, it is likely that the VOC only traded the steel, but it was very probably not made in Holland.

Íf I may go back to the initial question "Can we relate a MUMEI KANAYAMA TSUBA to a specific TSUBAKO", I would like to ask if specific KANAYAMA TSUBAKO are known at all? And if yes, how are they known when they never signed their TSUBA?

Haidar, you probably did not mean "folding a KATANA", but folding and fire-welding the steel. You are completely correct, folding modern steel to itself makes no sense. This is of course different in case you want to make a modern Damascus steel, using at least 2 different steel alloys. But that is not what you want in a KATANA. There are indeed methods to reduce carbon loss in fire-welding: 1) You need a big fire so very little oxygen can reach the steel. 2) Charcoal as energy supplier is better than mineral coal 3) Keeping the billet well covered with clay slurry before heating up 4) Keeping the welding temperature as low as possible 5) Using a flux like borax or rice-straw ashes 6) Starting the process with a high-carbon low-alloy steel so that after the forging, the blade retains a carbon content of about 0,7 or 0,8 % of carbon in the cutting edge. X) there are still more methods like keeping oxygen away by wrapping the billet in stainless steel foil a.s.o. "KATANA" has no plural form.

Yes, or read as KOKORO. On the right side I see JUGATSU - 10th month. Perhaps if you showed the complete TSUBA, we could get a clue.

Bruno, the second photo is much better! Looks like a date on the right side to me.

Paris, considering the general condition as can be guessed by a photo, it looks like early EDO JIDAI to me. The rather flat inlay might indicate that. But it could also be a late EDO piece that was not well cared for. HEIANJO TSUBA were also made as revival items.

Nice! A Tsaristic Russian 3 kopeck coin in an altered TSUBA! That might be a quite rare combo!

B. Ashton, in case you want to send me the SAYA, I promise to remove the paper in less than 5 minutes! It's not rocket science!

John, a permanent solution should be solid enough that you could handle the YARI without fear to break it. A double-threaded screw will not hold well! It would be no witchwork to have a slightly tapered thin-walled tube made from brass or steel. That could be either patinated or hidden under some cord wrapping to look "natural", and it could also be made in a way that the pole could be disassembled if needed.

Brian, as long as a weapon has a single cutting-edge, it makes sense to use an oval handle or pole, I think. It is different with KENDO SHINAI which are (almost) round, but are used as if they had a "cutting-edge".

I would have used an exactly fitting piece of a thin-walled metal tube, but that is probably just me as a "metal guy"....

Grev, I would understand this as NAOKATSU being the maker, copying a famous NOBUIE TSUBA.

Well, then use a longer wire!

It's almost invisible....

Of course a vacuum cleaner will not work unless you cut the end of the SAYA off. Please don't do that! Did you try my recommendation of a wire? It should be very easy!