OceanoNox

I will caveat that by saying that some iaito have very poor balance. Case in point, my shinken is about the same weight as my iaito, but it feels much lighter than the iaito. There are some iaito made especially light and thin to avoid injuries in beginners or people with less muscular strength.

I am 1m88 tall. My sensei had seen a few nice blades and had them sent to the dojo for us to try (another dojo member was also looking for a shinken). That blade simply fit me.

In iaido, shinken is recommended eventually. It may implicit, but for 5th dan onward, shinken is practically mandatory for testing and taikai. If you go to a dojo with high ranking practitioners, there are no mogito, only shinken being swung around. 900g is fine for a iai shinken. If it has a bohi, like most swords for iaido to avoid tennis elbow and such repetitive joint injury, it is not recommended for cutting, especially if you are a beginner, since it is a bit easier to bend. Weight distribution rather than total weight is more important for iai, but you need to swing the sword (single-handed) to check if the sword fits you. The sori and kissaki shape are also very important (I know a person with a sori almost like a tachi, but he is an exception). N.B.: For comparison, my own shinken for iai (I do ZNKR iai and muso shinden ryu) is 79.6 cm long (sori is 2.0 cm) and about 970g. The blade tapers towards the tip, and it feels like a feather compared to my mogito.

Do you remember where you read/heard that? It's very interesting to me. In my comment above, Isawa talks about failure (and I think there is another who talks either about mekugi failure or failure at the habaki). My student did a calculation, and the kachushi tsuba with a thick mimi "keeps" the shockwave bouncing around in the tsuba, for instance. I wonder who much it is mitigated with everything else. PS: It might be Yaso who published a paper about impacting a Japanese sword. They identified the nodes: at the monouchi and at the mekugi, i.e. where the vibrations are smallest. When doing it on a naked blade, there was some vibration at the nodes, but with a full koshirae, the vibration was basically 0 at these nodes.

People don't aim typically for the sword either, but if you block and control your opponent's weapon, a guard of some sort helps with that purpose. With how it's wielded, a tsuba also makes a lot of sense on a nagamaki than a naginata. @O koumori here are some info I got from earlier sources about tsuba: "鍔は只拳の楯と聞物を太くも太くもなきは非がごと" in a Hayashizaki shin muso ryu scroll dated from 1601 (if memory serves). This one calls a tsuba a "shield for the fist(s). Tsukahara Bokuden wrote: 鍔はたたふときにしくはなきものを細きを好む人そ拙き 皆人のしらてや恥をかきぬらん鍔のつめある習ありとは 鍔はたた切ぬき有を好むへし厚き無紋を深く嫌へり あら鍔はいかに厚くと切れぬへしたとへ薄きも古き好めり It does not directly refer to tsuba as hand protection, but states what should be preferred in terms of design. In 1719, someone called Isawa (井澤蟠龍子, in 武士道叢書) wrote: "鍔は無地の厚きを用へし 大サ三寸四五分短刀（わきざし）の鍔三寸ほどにすべし 見るところのよろしからんを思ひてすかしあるうすき鍔を用べからず打合とき切破ことあり" which states a preferred design for a tsuba to resist blows (along with the sword itself). I couldn't get the direct citation, but it's cited by both Nagaoka (1942) and Sasano (1975): in the essay 鈴林類纂 (Edo period), tsuba are recommended to be essentially like kachushi tsuba (thicker mimi than seppadai, have some, but not too big, sukashi). The shape would prevent damage to the mekugi when hit, and the small sukashi would prevent blades from going in them or catching them. Now, the issue is why all those are not in accordance with one another about design. At any rate, the first is clear, the others are less direct but imply that tsuba are hand protection. The funny thing to me, is that all the works that say tsuba are for slip prevention (like in the Art of the Samurai: Japanese Arms and Armors 1156-1868 catalogue of the MET), I have not seen any period source being cited.

Unfortunately, I have even seen the MET catalogue on samurai, written by the Tokyo National Museum curators, specifically say it, adding that it was not for protection from blows. Sasano as well talked about the tsuba being to prevent slipping, because thrusts are the best attacks against someone in armour. Nevermind that we have tsuba on tachi, whose curvature makes the idea of a thrust dubious. Just like @Jacques wrote, koryu teach to use the tsuba to protect your hand or catch an enemy's weapon. Shinkage ryu does too. It is clear from koryu documents that tsuba were thought as a protection from blows for the hand.

Some of the results come from a study made by Nippon Steel (新日本製鐵第一研究所) using CMA (Computer-aided Micro Analyzer or Comprehensive Multi Analyzer). It seems to be like EPMA but faster and with a larger analysis area. Unfortunately, the paper does not give the details of the research report...

I have to admit I haven't read much outside of academic work on Japanese swords. I am trying to remedy that by reading stuff written by Alan Williams, and get to other stuff, the goal being to understand the similarities and differences in methods and goals when making swords (I am still not sure why the Japanese apparently aimed for such high hardness). That being said, so far, the body of academic work on Japanese swords, in particular material science and mechanical properties, is quite consistent, whether it's about old swords or modern ones.

I cannot say whether it's useless or not, but the paper, and others that deal with Western swords made in the same way, shows a banded structure in the cross section. I think the idea is less to have a uniform carbon content and more to have a composite structure "throughout". There are also swords that seem to be made of one type of steel. To be honest, my feeling is that the author worked from the conclusion backwards to find fitting evidence, instead of gathering evidence to come to a conclusion. I don't think they misrepresented the sources they cited, but I was left wondering how representative their examples were.

The title seems like clickbait, here is the original title and reference info: 日本刀の素材は本当に玉鋼か？刀剣類の分析から素材鉄の変遷を考える, 大村 紀征, 金属 Vol.94 (2024) No.7 The conclusion of the paper is that tamahagane was mainly used for Japanese swords merely during the Bakumatsu (specifically the last 70 years of the Tokugawa Bakufu). Arguments are: 1. Little local production of steel, that did not match consumption and demand; 2. Large imports (either official or contraband) of iron and steel from the Chinese mainland and the Korean peninsula, with added metal from Europe later; 3. Steel from the Chinese mainland contains more copper than the iron sands in Japan, and several extant swords that were analyzed show a copper content congruent with Chinese steel. 4. The whole "hard steel for edge and outside, soft steel for the back and inside" construction of nihonto is relatively new, and older swords (in particular koto) were made with mixing soft and hard steel, folding/twisting them together and forging the sword from the block (same as several swords found in Europe too). 5. Analysis of some iron/steel items imply they were made by mixing non-Japanese pig iron and native iron sands. Personal impression: The author does not appear to mention export of swords from Japan to China, nor the pervasiveness of recycling and oroshi. He doesn't cite other studies that show virtually no copper in Japanese swords from Kamakura to Edo (Prof. Kitada, 日本刀の材料科学), i.e. the use of native iron ores to make Japanese swords. I am yet to understand how they obtained (maybe from another study?) the numbers for production and demand of iron/steel items during the history of Japan. The paper itself is certainly trying to shake the established idea, relatively new according to the author, that nihonto = tamahagane, but as of yet, I lack the time to review the sources and studies cited in the paper, and the knowledge to agree/disagree outright.

My apologies for the thread necromancy, but I stumbled upon this article: https://www.research...Edo_period_1603-1868 The sources cited appear reliable (at least the ones I know). If the estimations are correct, some iron tsuba would be a few tens of euros.

Leaves with dew drops maybe? And this is why I think nunome is not so good for the long term, all the precious metal ends up somewhere else than the tsuba.

This is one of the only example that seems like a credible sword scar on tosogu: http://www.ksky.ne.j...9/katanainfight.html Also: http://www.ksky.ne.j.../tsubaradiation.html Here is another discussion on the topic, if you haven't seen it before:

A colleague of mine also has the 廣 kanji in his name. In that case, it's not related to old or new, that's just the way of writing it, and he said he accepted the use of 広 because the old kanji is not always known. As far as I know, on official papers, it should be 廣. I cannot comment on why the NBTHK used the new kanji instead of the new, especially if the mei uses the old kanji.

The top right of the first photo uploaded by John shows some crossing lines. As I understand, the nunome pattern should be removed after adding the wires and foils. I wonder if the person who made this tsuba had difficulty in removing the lines (I have seen artisans use a burnisher to "blend in" the lines). At the same time, since the gold is on round surfaces, maybe it was difficult to make a clear cross pattern in the first place. Regardless, in nunome zogan, the precious metal inlays are not completely flush with the iron surface. They are necessarily a bit proud. And you can get what is shown in the Aoi website links: the top surface of the inlay is removed, and gold remains in the grooves. You can see in this other example that the gold wire is still a bit raised (from ~9:30): As an aside, the modern fittings on my shinken for iai are all some kind of nunome zogan. Sometimes you can see the nunome pattern, sometimes not, but more importantly, because I use the sword regularly and it rusted, a lot of it has fallen off, pushed by iron oxide growing from below. I love the patterns that can be done, but I much prefer actual inlay.

I like the tsuba. The only issue one could have is that the tagane marks were not completely removed after inlaying the gold wires. Here are a few drawings explaining further the principle (for Higo zogan, but the same principle) (although Ford's videos are explained in much more detail). I think the pictures are clear enough that Japanese knowledge is not necessary. https://plaza.rakute...o.jp/higokinko/2000/

Rather than the hitsu ana defect, I am confused by the "dots" on the ji (I feel they would either be depressed, or look like nanako, but here, they are proud of the ji that has little hint of the use of tagane or punches), and the somewhat flared border of the nakago ana (especially beside the mei). Not being aware of the details of the sanmai process, it doesn't quite look handmade.

I'd like to see a document that describes that very special method that us stupid gaijin don't know about. I did not see anything like that in several old books (鐔に見る日本の意匠, 鐔芸術考, 鐔入門 : 百人百鐔, or even 人倫訓蒙図彙). I don't recall it being mentioned in Western publications either. So, something that Japanese and non-Japanese experts don't know about... But we do know that charcoal and urushi were, and still are, baked onto the surface of iron items. But what do I know, I am a stupid gaijin.

Easiest and fastest is X-Ray Fluorescence, but it will only get the patina composition. But this is already a big thing, because the recipes for patina should vary according to various places.

Is the mimi uchikaeshi? If so, I am amazed at the skill required to make it look so good. Very nice!

Thank you Manuel and Jean for the information. It was really helpful.

So that is why umegane sometimes look like they curve a bit towards the hitsu ana on their periphery! By inlet, did you mean that the ends of the nakago ana are expanded to insert the sekigane, or that the wall of the nakago ana had a small groove inside? Thank you for the answer.

I have been looking into sekigane and umegane in general recently. Sekigane because the iai swords I have usually don't have any (and antiques sold for iai do not either), and umegane because I think they are a very interesting way of using the hitsu ana when there is no kogai or kozuka. However, I cannot find much information (yet) on how they are made. I recall, when our dear departed Ford had a picasa page, that he said the sekigane held simply by friction. I understood it as meaning one would hammer it in place, and cut it to fit the nakago. The roughness of sekigane in general seems to confirm this assumption. I assume it is the same for umegane, but the finish is quite much cleaner for umegane in general. Do you know if there is a specific method to adding umegane? Is it simply hammered in place, and then polished and engraved? Could there be grooves carved in the wall of the hitsu ana to help secure them? Or would they be melted in cast in the hole?

Just taking a quick peak at the Owari section, and it's quite the leap from the original Japanese. I cannot understand how they got from 上下張り気味 (tends to be stretched up-down/vertically) to "squared seppa-dai". Likewise, going from 精良 to "hard and refined" (it seems to simply mean "excellent", which could be translated as refined, i.e. that forging took place to make the iron cleaner, but it does not imply hardness at all; 精 can mean strength, but more in the sense of vigor, it is incidentally one of the kanji for semen, to show the meaning of "vigor").

I don't know if this would work, but for starters, an evaluation of several dimensions for all extant tsuba would be a start. When I used the measurements from books and online collections, several times, only thickness or diameter were indicated. Proposed measurements: ➀ Easy and non-destructive: Thickness at the rim, thickness of seppadai, height/width of the tsuba, height and base width of the nakago ana, weight, shape of mimi. → This can be done readily by everyone, hopefully without scratching anything. ➁ Not so easy, but non-destructive (hopefully): Design trends (motifs, overal area cut out): possible use of AI for image analysis and treatment, Neutron diffraction (chemical analysis of iron, evaluation of forging), X-ray (chemical analysis of patina). → AI network for image analysis is being done currently. However, I have no idea how one would implement the analysis of designs. The measurement of total tsuba area and sukashi area seems straightforward, provided clear contrasting photos are used. I have personally done measurements of areas covered by specific features over total observed area, and it can show nice trends, but it is very very time consuming. → Neutron diffraction and X-ray analysis (XRF) were done by Barzagli and Kawami respectively. The XRF one is relatively easy because the tool can be rented (it's like a big hair dryer that one points at the item), but neutron diffraction is very difficult simply because one needs access to one of the few research centers that have it, and it means getting the tsuba there (as far as I understood, it's possible here in Japan to get neutron diffraction done for relatively cheap if the results are published in an open access journal. However, there is always the issue of handling at the facility and taking out the item from wherever they are stored/displayed). ③ Destructive: Hardness (micro Vickers is considered non destructive in the industry, but for antiques...). → Quite easy, although to get reliable data, a minimum of polish is typically required. Mr. Nakamura has shown such data in 1963 for several dozen iron tsuba, showing some scatter in hardness (hinting at either some forging or the combination of various irons and steels). A specific workshop or artist is unlikely to limit themselves to specific dimensions and materials. But if there are specific traits for various schools (presence of tekkotsu, prevalence of specific designs), the establishment of this kind of database could help narrow down possible origins of tsuba. With previous comments on papers being more liberally given in recent years, I do wonder whether the financial incentive to "mistakenly" attribute tsuba to famous craftsmen can be overcome. Certainly, it is possible that with this kind of inflation of paperwork, less stock will be put into those certificates, and a new system might be adopted.