ROKUJURO

Lee, unless there are special exhibitions, you will see swords mostly in museums and often on the 5th floor of important warehouses like MITSUKOSHI. As I have heard, most dealers don't have swords on display, so you cannot just go there and have a look unless you want to buy..

Nazar, I saw this as well, and I would like to see if the MACHI truly align.

Frank, the signature is chiseled and read vertivally, tip-upwards, so I broke my neck for you to read KUNIYUKI. I cannot read the first KANJI of the province. It does not look like a typical WWII blade, but to say more, we would need god photos of the naked blade. Have a look a your PMs.

Ken, in that condition, it will be very difficult even for a professional photographer to show more of the features. The blade would need a professional (= traditional) restoration first. Please do not try this yourself! What can be found online about HIZEN TADAYKI is not much: In the Hizen Tadayoshi lineage, Tadayuki is a historically significant figure during the late Edo period. When the 6th and 7th generations of the main Tadayoshi line passed away prematurely, Tadayuki (a senior disciple) took over the forge, managed the school, and successfully mentored the 8th generation of Tadayoshi (Hachidai Tadayoshi) until he reached adulthood. Notable Characteristics of Tadayuki Blades Steel and Grain: Hizen blades are renowned for their highly refined Jigane (surface steel) and often display Konuka-hada (fine "rice bran" grain). Quench Lines: Tadayuki blades frequently feature elegant notare (wavy) or suguha (straight) temper lines. Signature: Signatures will typically translate to "Sesshu Ju Fujiwara Tadayuki" (for the Osaka lineage) or "Hizen Koku Tadayuki". For a comparison of an authenticated example: https://www.samuraimuseum.jp/shop/product/antique-Japanese-sword-katana-signed-by-tadayuki-nbthk-tokubetsu-hozon-certificate/?srsltid=AfmBOoryBB8LXnS2Kd3kM4r8Eh__2DDliIlbbIU8-jv6KstOCvXelvCq Roger Robertshaw is an expert on HIZEN swords: https://www.hizento.com/author-book-roger-robertshaw-tadayoshi.php I believe he is a member here.

John, in that case, wouldn't it be easier to take some material off of the wooden scabbard liner?.

That was the guy who "cleaned" his car with an angle-grinder....

I experienced the shut-off as well.

Ken, the photo of the sticker(s) ( I see two of them as well) is upside-down, so difficult to read.

Beautiful, I like them! No sloppy work, perhaps sold before finish was completely done?

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Aiden, if ever you get your hands on genuine Japanese military blades, please post images of them in the military section. This NIHONTO section is for traditionally forged authentic blades.

Hi Glen, thank you, very interesting and helpful! One of the factors you did not mention is the making of a TSUBA. I believe this will be most important. As you say, we shall see....

Criss, the photo is not oriented correctly, it should be turned 90° to the right. The "signature" may be read as ISHIKAWA (= stone river). It is still not an antique item which you can test with a hot needle.

And one for me please!

I am confident that one of our native speakers (or SteveM) could contribute to the partial KANJI. Perhaps post it in the TRANSLATION section.

Christian, I apologize to be boring you with this subject, but we are actually only 'scratching the surface' of it. There are many factors which have to be looked at, and what actually seems like well-kept secrets may have been something so evident to the old TSUBA masters that they thought it not necessary to write about it. Of course, it may also have been business secrets! All we can do - and what we are actually doing here (and I appreciate the scientific exchange with Arnaud a lot!) is trying to explain features which in the past have been described wrongly by early authors. You are welcome to take part in this discussion, but you would need to know some chemistry facts. Please read this in German: Eisen ist unter normalen Bedingungen sehr beständig gegenüber Alkali (basische Lösungen wie Natronlauge, NaOH). Im Gegensatz zu amphoteren Metallen wie Aluminium oder Zink, die sich in Laugen lösen, passiviert Eisen in alkalischem Milieu, was bedeutet, dass sich eine schützende Oxidschicht bildet. Reaktion von Eisen mit Alkali im Überblick: Keine Normalreaktion: Eisen reagiert bei Raumtemperatur nicht mit verdünnten oder konzentrierten Alkalilaugen. Passivierung: In Gegenwart von Sauerstoff und Alkali bildet sich eine schützende Passivschicht aus Eisenoxiden oder - hydroxiden, die das Metall vor weiterer Korrosion schützt. Hochtemperaturreaktion: Erst bei sehr hohen Temperaturen (über 700°C) oder unter speziellen elektrochemischen Bedingungen (z.B. Bildung von Ferraten) kann Eisen von konzentrierter Alkalilauge angegriffen werden. Alkali-Einfluss bei der Eisenerzverhüttung: In Hochöfen können Alkali-Verbindungen (aus Rohstoffen) die Eisenträger (Sinter, Pellets) beeinflussen, indem sie die Schmelz- und Reduktionsprozesse verändern. Zusammenfassend lässt sich sagen, dass Eisen im Alltag gegen Laugen weitgehend beständig ist. Back to the main subject. Arnaud, you wrote: .....do you have a theory, or are there info about the acids used (I always imagined it could be vinegar)? From Ford Hallam's opinion that a lot of the texture was made by chisels and textured hammers (possibly anvils?), I wonder if this kind of mechanical texturing process was not combined with heat to force surface "damage" via oxidation. Then removal of that with acid, finishing touches, and controlled patination. I suppose, aside from asking artisans who make similar stuff (are there any?), and barring the finding of documents detailing the process, we are left with our own experiments to confirm what kind of process could yield similar surfaces to the antique tsuba..... I do not know what chemistry science was like in medieval Japan, but they had masking techniques (wax, URUSHI) and used them. Organic acids were available through all forms of fruit acids (did you ever experience the reaction of carbon steel with tomato juice?), vinegar, and other aggressive media like animal dung. These work certainly slowlier than our modern concentrated acids, and possibly needed another form of treatment like cleaning up in the process, but as time was not a limiting factor, it was possible. It is also possible to produce nitric acid from potassium nitrate (KNO3) which was available in Japan. Coming to texturing, Japanese craftsmen indeed used a variety of very specialized tools, and unfortunately, the different surface textures are often not recognized or described wrongly today because we lost the contact to the craftsmen's realm. ISHIME, TSUCHIME, MIGAKIJI, KE BORI, KATAKIRI BORI, scraping, stippling, burnishing and many other techniques can be applied. All surfaces were patinated which helped to prevent a TSUBA looking "new", and at the same time, protect against corrosion (at least for some time). And to answer your question: Ford told me that no living TSUBAKO could produce TEKKOTSU, so there is still some research to be done. I am on the track.....

Yes. possible. It is MAGOROKU

Grev, the photos are all out of focus, but in case bamboo had been used, I would also think of a DIY box.

Arnaud, as far as I know, the Japanese swordsmiths of olden times did not have furnaces with a vacuum chambers.... In case you can bury a workpiece deep in a charcoal fire, you will have more carbon monoxide and thus create less scale, but the higher the temperature, the more reactive with oxygen the iron will be. So scale will not be avoidable in any open fire. Using water on the anvil while pounding will blast most of the scale away. It is generally overlooked how much material is lost in firewelding. The necessary high temperatures "burn" away the steel at a high rate, so only 25% of it is left in a blade after 12 to 15 foldings. However, there is a considerable difference between iron and high-carbon steel.

Perhaps MINO 美濃 ?

Thank you Arnaud! Your results are exactly as expected! Higher temperature would have produced still more scale but not a "melted" surface.

James, the MENUKI may be pure gold or gold-covered. You will have problems seeing that mounted, so - as Geraint stated - when the TSUKA-ITO is being redone, you can have a look at the backside of the MENUKI.

High Octavian, welcome to the NMB forum! You have posted in the NIHONTO section which is thought to deal with traditionally made Japanese swords. Your sword was probably machine-made in WWII, so it would be a good idea to post your request in the military section as we have some experts there. For relevant answers, your photos should be made on a dark, non-reflecting background, light-source from the side, with the blade pointing verically upright. The NAKAGO (= tand) is important to show without HABAKI and also vertically so any signature could be read. Good luck!

What can be found in the literature about YAKITE has not been tested by the authors and is pure assumption. The surface of a TSUBA may indeed LOOK LIKE MELTED (perhaps something like TOKA ME in Japanese), but it is definitely not! The melting point of pure iron is 1.538°C, wrought iron has some impurities, but almost no alloy metals content, so its melting point can be assumed to be about 1.480°C. In case you heat an iron object up to close to that temperature, it will deform on the underside as well, destroying any design that may have been created before, and it will take on the structure of the ground it is laying on. So this would never work! And the build-up of scale on the surface has not even been considered!

Florian, there is no "fast and easy" in TSUBA making! The discussion about iron/steel in TSUBA is finished. To have the desired function, it has always to be iron, never hardened steel (or cast iron, for that matter). You can try your personal methods on my TSUBA forging workshop.