ROKUJURO

Chris, this I learned the other way round: saltwater is a faster quenchant.

Jacques, I don't think you can say so. Instead, Japanese swordsmiths used water because the method was working to their satisfaction. Pure high-carbon steels require a rapid quenching to produce martensite, and this can be obtained by water quenching. In the West, we don't use these steels any more, except for special purposes, so industrial alloyed steels are dominating. Quenching a modern toolsteel item in oil at appropriate temperatures will of course produce vapour in the first few seconds! You can also see bubbles, and that can only be reduced by agitating the workpiece in the liquid. The same is done when you use water, but this is rarely seen with Japanese swordsmiths. Interestingly, warm oil provides a faster cooling rate than cold oil, which has to do with the viscosity. Warm water (the temperature of which was kept as a secret by the master!) as used in swordsmithing reduces the cooling shock and helps to reduce the risk of HAGIRE.

I would like to add that a smith does not have a free choice of his cooling liquid. The respective steels are different, and while a pure TAMAHAGANE based carbon steel is very likely not to get hard in oil, an alloyed tool steel may crack when cooled in water. Until recent times, there was no metallurgical knowledge in Japan, so the safest way was to follow the master's instructions. Everything in this field was - and is - practice and experience, and that is why Japanese craftsmen generally cling to their traditional methods.

Ken, I see no contradiction to what I wrote. May I add that in medieval times CHOJI oil for sword care was probably not basically paraffin oil, but some natural mixture. Concerning metal polishing with calcium carbonate see http://www.abrasivesformetal.co.uk/Vienna-Chalk.aspx

When I mentioned the effect of oil on whetstones, I referred to solid stones, not powder. The UCHIKO powder, mixed with oil, is said to have a grinding effect. As far as I know there are different qualities of UCHIKO. It seems that some polishers use leftover UCHIGOMORI stone and grind it to fine powder for use as UCHIKO. In other sources it is said that fine limestone or other calcium carbonate sources are used. All these powders may be abrasive if used with pressure or over a long period of time. I try to imagine how you are pushing your UCHIKO very carefully in front of your paper, but in a 100 years from now, when you look at your blades, you may be disappointed by the result! :D The traditional system of sword care was based on regular cleaning and oiling, which made sense in the maritime climate of Japan. If you only oil your blade, it will polymerize (in case it is a natural oil) and cannot be removed frome the tiny holes which form the HADA. Depending on your climate, it may be a good idea to use a water-free chemical solvent to remove old oil, together with a soft tissue like medical cellulose swabs, before you oil again.

This is a different subject but as we are talking about abrasive effects of UCHIKO, it may be tolerated by the BIG BOSS. Natural oil stones are called so because they are to be used with a kind of oil. These stones are not porous and do not soak up liquids. Examples of oil stones are the famous Arkansas and Ouashita stones of the U.S. BUT these should not be used with a lubricant oil, instead one should use what is called different in different countries: Petroleum, petrol, kerosene, lamp oil a.s.o. These are all low viscosity hydrocarbon fractions of crude oil. Some have a bad smell, others are artificially perfumed (there is a variety of non-perfumed lamp oils on the market). These dense sharpening stones, when used with lubricant mineral oil, loose their abrasive capacity and have to be cleaned. Some can be cooked in water to reanimate them, others can be soaked in chemical solvents (not good for your little lungs). So called 'water stones' can take up more or less water, and they are mostly to be used with this liquid - there are a few exceptions among artificial grinding stones. Generally said: None of them works satisfyingly with oil of the lubricating type. As I got the pencil in my hand: UCHIKO is chemically a calcium carbonate. This can be obtained by grinding up limestone, marble, mussel shells, chalk (blackboard chalk is plaster, not lime) and others. These are hard materials, even cristals in some cases. Not only in former times but still today, calcium carbonate was used als polishing material by goldsmiths (Vienna Chalk, calcium-magnesia carbonate). But there is also a very soft calcium carbonate produced by chemical precipitation. Almost all of these materials can - and do - scratch fine surfaces, depending on the size of their grains. Polishing means that the unarmed human eye cannot see the scratches because they are too fine. A magnifying glass or a microscope will always show scratches! So, the basic material UCHIKO is made of will decide if you scratch your sword blade, depending also on the sieving process to eliminate coarse grains. In the long range even the best UCHIKO may affect the steel, especially when rubbed with pressure, thus creating a shiny (polished) surface where you rather want to have a matt one. Concerning the so-called CHOJI oil for sword care, it should be known that cheap qualities only contain an homeopathic amount of genuine or natural CHOJI oil. The basic material is paraffin oil, and CHOJI is added as a fragrant only. On the other hand, paraffin oil is not so bad a choice, because it does not deteriorate or polymerize. But it is known that the properties of paraffin oil to stick to a metallic surface to build up a protective film are weak. So the protection is only realized in the tiny openings of a blade surface which we call HADA. Fine UCHIKO as well as chemical diluents can remove oil residue from these very fine openings. So what has been said on sword care is certainly true: you have to know the conditions your blades are stored in, and clean and protect accordingly with the softest and best materials available. Denaturated spirit, depending on the country of origin, can contain harmful substances that are known to cause cancer (Germany). So it may be a good idea to clean your blades in the garden.

JUNICHI, the second and third of your TSUBA probably display a fern sprout design, I think.

Gentlemen, the article about the production background of MANTETSU blades is valuable, but some detail problems arise not only from the obvious difficulties of translation. It says: ......Dr. Kazuharu Kusaka of South Manchuria Railway Central Research Institute did electric steel manufacture of the sponge iron (rich iron ore from a Manchuria), and he succeeded in manufacture of the good steel near malleable iron...... Well, I would like to add that sponge iron is NOT 'rich iron ore'. Obviously, Dr. KUSAKA had a good quality iron ore source there and was able to produce raw steel. As this cannot be forged, they used probably electric energy in a second process to remove the surplus carbon content from the steel to make it malleable. This is generally a modern standard process of steel production, and depending on the purity of the iron results in good quality steel. Our modern steel production differs from that in that we use to add large quantities of scrap steel to the process, resulting in the production of alloyed raw steel with partly unpredictable properties. This material cannot be purified after the process. If I understand the article correctly, the purity and good quality of the base material and the process, designed to produce high quality tool steel, made all of the difference.

I guess these fall in the same range as a Bugatti or a cheap Lamborghini today! Gorgeous! Thanks for letting us participate!

Christophe, I may add that the thin press-molded surfaces (both sides usually the same) of SAN-MAI TSUBA were usually not glued. Some were soldered, if not fixed with a rim as already mentioned.

Alex, how old is old? There are some really fine 'old' iron TOSOGU parts to be seen, and the Japanese craftsmen had no problem to achieve a very fine finish even on iron or steel. Have a look at some HORIMONO or good TSUBA! I did not want my remark to be understood as an evaluation or criticism, but when we talk about pictured KODOGU, a closer look should be allowed. In this FUCHI (I wrote 'special' because I meant the FUCHI here in discussion) you can clearly see that the traces of the tools had not been removed. Lines which could be straight aren't, and as we do not know the intentions of the respective craftsman I expressed the opinion that it was perhaps made to look 'old'.

Good morning! The subject of KAISHO symbols on KODOGU has already been dealt with a year ago (ancient KANJI designs, in TRANSLATIONS, Jan. 30, 2012). This special FUCHI looks somewhat crudely made, maybe to underline an appearance of age? Lance, I don't remember a change of altitude in the SHIN-SHINTO period!

I think I can read ....no KAMI KANEMICHI but I have no books at hand to look the smith up. It is not TAMBA.

Maybe it is my eyes but I read an attribution to KODAI HIGO.

I like that TSUBA, although the surface and the TAGANE marks near the NAKAGO ANA are indeed a little strange. I don't think that it is a cast one but I believe that it once was heavily corroded. What I would like to know is what is meant by the term 'HENKEI iron'. This term was used as 'bent' or 'distorted' in another TSUBA's description. Could someone please give an explanation? Thanks in advance!

It is exactly as you say: you are striving for an airtight fit, so glueing in pieces of wood and fine-tuning the contact zone between HABAKI and wooden inserts with tools is the work to be done. You will want also to respect the angles of the wedge-shaped HABAKI. NEKO GAKKI are indeed made to improve the secure fit of the blade in the renovated SAYA.

Denis, my experience is just the contrary, especially when you use a quality rasp (Japanese tools are usually among the best available). A good new rasp will easily remove a lot of material with little effort, depending on the size of the teeth and their number! Of course this is only the first step in the work, and the surface has to be smoothened afterwards with other tools. Rasps are made in a wide variety from very coarse to quite fine. The mentioned NAMIKAWA rasp is quite slim and very long, it's working part has the cross-section and shape of a blade, and it is made to adapt a used SAYA to another blade with a slightly different SORI and thickness. A KOIGUCHI needs only very fine tuning when you start with thin wood strips. A few sharp knives (small KOGATANA for woodworking) and a good file might do the job then.

Yes, we can! The secret is not only to find thin strips of wood but to rework the glued-in pieces with a rasp and make sure the KOIGUCHI has a tight fit to the HABAKI without causing pressure. As has been said this is a standard service for SAYA in use, and SAYASHI prepare fine pieces of soft wood for that repair. Also, the Japanese have a number of fine woodworking tools for this purpose, e.g. a long SAYA rasp can be obtained from NAMIKAWA HEIBEI, but your local tool dealer might have something less expensive. A coarse file will do, but never use sandpaper! In many cases, old SAYA may also suffer from a broken horn KOIGUCHI, which might get dry and brittle with age. It can be replaced but this will demand some fine work and use of URUSHI. I wish you good success!

The explanation for that phenomenon is rather simple: the forming energy of the hammer blows causes internal friction in the material - just imagine the molecules 'rubbing' onto each other. This can generate as much heat as to ignite a piece of paper. Even if the steel in the video still looked to be black, it might have had a temperature of about 600°C (not easily visible in daylight). In the process of forging an object, the heated steel naturally looses it's temperature, but when intensively worked on, you can see the red heat coming up again a little with heavy hammer-blows. Try this at home, if you have an anvil and a 2 kg hammer, it's a good work-out!

Yes, they call it a HIGONOKAMI. Available in better knife shops, in Germany also at DICK's in Metten. Same type of pocket knives as Mercator, Douk-Douk, Opinel a.s.o., but much better blade quality, usually double layered.

Looking at the TAGANE marks near the NAKAGO ANA I have the impression that they are not smooth and even in their surface. As they are normally made with the polished tip of a tool, they should not be grainy or sandy. Have a close look with a magnifying glass and in case they show a granular texture you can assume that your TSUBA was made by casting. Corrosion produces a different surface texture.

Martin, look for info under KAGAMISHI TSUBA. ......Kagami-shi tsuba and kagami One of the categories of irogane ko-tsuba, (or "old" - that is pre-Edo - soft metal tsuba) are kagami-shi tsuba, which are said to have been produced by mirror makers. Those artisans, the kagami-shi, have manufactured sword guards using techniques applied in the production of their mirrors. They have cast them in bronze........ The TSUBA in question depicts probably DAIKOKU and EBISU, and this subject has indeed been used extensively for this kind of TSUBA. While the old examples were made carefully in a one-by-one technique, late copies could be produced in large numbers. This one looks to me like a very late one.

The first two KANJI may be OKAMOTO - just a guess!

In my understanding, the easiest parts in copying a handmade blade are the signature and the ageing. I am not an expert, but the Chinese fakes I have had in hand did not really look close to Japanese blades and could not have been mistaken for those. However, making intentionally a copy would mean some effort, and I don't believe that even Chinese smiths can forge blades 'the cheap way' if they want them to look so Japanese that they could deceive the experts. So at the end, I cannot imagine a truly nice blade being made in China, and if there was really any question as to the origins of a blade, it could be easily ascertained by spectroscopy or other reliable methods.

You mean MEIJI TSUBA? There is no reason why somebody could not have replaced a nice TSUBA with this one, perhaps before selling the whole. TOSOGU have always been mixed or interchanged, and you can feel lucky in case you find a matching KOSHIRAE together with a good blade. Compared to many EDO SOTEN copies I have seen, this TSUBA is especially crudely made, so it might well be a late tourist piece.