ROKUJURO

Sorry, I cannot contribute to the 'feather' subject, but I know that it is difficult and expensive to buy KYUDO arrows with eagle feathers (even without closer specification) from your standard KYUDO shop in Japan. Nevertheless, a real specialist might help. What I am interested in are the arrowheads. Do you use old and original items or do you really buy NEW ones? As a smith I am interested in this subject, I have forged a small number of these and would like to see some pictures of original heads if you have.

Although this is not related directly to KANEZANE swords, I would like to mention that martensite has a slightly higher volume than the same amount of steel that it is produced from. In quenching, this expansion mainly causes the bending of the blade, resulting in it's SORI. If the balance of expansion of the HA area and the shrinking of the MUNE is not well, the blade may develop HAGIRE immediately or at a later point of time. So the construction of a blade plays an important role and experience and skills of a smith are crucial for good results. Generally speaking, industrially produced steel (even when called 'carbon steel') is likely to contain different amounts of alloy metals, while TAMAHAGANE is very pure and does not contain any additional elements except carbon. Industrial steel in small cross-cut dimensions cannot be hardened in water without the risk of cracking, TAMAHAGANE on the other hand will not produce the features Paul described above when quenched in oil as this is a very rapidly transforming steel which requires a rather 'brutal' cooling.

Jacques, as I pointed out:....' a YAKIBA will always go through the material of the blade as long as the cross section has a sufficient carbon content to be able to harden.....' Chris said the same in other words. In most cases the SHINGANE will not harden because of an insufficient carbon content. I don't have correct measurements of the blades in question, but we know that the MUNE rarely exceeds 8 mm, YOROIDOSHI excluded. Even if one or two millimeters of the steel core of a very thick blade should not harden, you will not get down to that point by polishing (hopefully). The hardenability limit of steel is 0.22% carbon.

The cross section pictures quite clearly show that the hardening can reach into the steel more than 1,5 mm (the darker areas), as far as I have learned it is about 4 mm. These very clean steels used by Japanese smiths are able to change their molecular structure very rapidly which is the reason why they should be quenched in water. Modern industrial steels - even if they are called carbon steels - contain small amounts of alloy metals besides carbon and are likely to crack when cooled down rapidly in water, so they are quenched in oil. From the technical point of view a YAKIBA will always go through the material of the blade as long as the cross section has a sufficient carbon content to be able to harden. A HAMON may change it's appearence if polished many times but as long as it is not polished away from the HA side because of age or chipping or damaged by fire or heat it will be visible.

If my old eyes are still working correctly, the TSUBA shown is not the same as pictured in the KANSHOKI. Nevertheless it is pleasant.

Curran, please be so kind as to explain what you mean. I am capable to differentiate between visible lamination in a steel, TEKKOTSU and a seam caused by casting in a mold. I can reproduce these effects in my forge. But there is no such thing as a 'forge seam', and that is what I wanted to point out.

David, Being a smith myself, I have never heard about 'forge seams' except in 'drop forged' items (tools) which means they were press-molded in an industrial production process. If you should find any kind of 'seams' in a TSUBA, this could well be hints for a cast TSUBA. TEKKOTSU is definitely not a 'seam' but in all probability a sign of inhomogenous steel base material. It shows up in the chemical treament after the forging process. If you really find forged down TEKKOTSU on a TSUBA then this must have been made after the manufacturing process, and certainly not by the TSUBAKO himself. We have been discussing this subject here in the forums.

Pete, thanks for you comment. My statement was partly based on my experience with IAIDO, and I learned about the placement of the SUKASHI from a SASANO pupil, so it is nothing I invented. Instead, I always thought it to be quite logical, the more as I was shown some TSUBA with slight but visible wear or rubbing on that contact spot with the knuckle. Maybe others here in the forum made the same observations?

In the manufacture of a TSUBA of that kind, there are only very few tools needed. An experienced KAJI would have no problem in forging a small lump of steel down to a flat plate with a fine and even surface (TSUCHI-ME JI) as needed for TOSHO-type TSUBA. Filing may only be necessary on the MIMI for some minor corrections of the circular shape. The slightly 'bellied' shape on the URA side found in some TOSHO TSUBA is not at all difficult to produce, but it is always intentional, and of course you need an anvil for it's production. The outward taper may have to do with the comfort in handling the weapon, comparable to the position of the KO-SUKASHI which in almost all cases is located in a way that it does not interfere with the knuckle of the sword-hand. Fire or heat on a thin TSUBA plate will not cause two different surfaces unless the affected side is exposed for a longer period of time. This has to do with the rapid heat transfer in metals. On the other hand corrosion could occur on one side only if the TSUBA in question was positioned flat in a damp place or on something moist.

As far as I know from my experience as a smith, the carbon content of cast iron can go up to 4%. To convert it to malleable steel you want to go below 2%, so the process should be decarburization. I think this was what you wanted to say.

I like it also, it is a very nice one! Is it only me who sees snow on the bamboo leaves? I did not read that in the description.

When you forge-weld sheet metal of steel (with carbon content, a material that can be hardened) and iron (with a very small carbon content of sub 0.22% so it cannot be hardened), and you grind one side flush and even, you will see that with further forging and hammering it is the softer iron which protrudes between the layers of steel. From my experience as a smith this is logical and expected. I know that in TSUBA literature every author repeats what he has read in other books about it, but no one ever has questioned the real cause and researched in this subject. I think that TEKKOTSU is softer iron squeezed out between layers of steel. Many TSUBA have undergone chemical treatments not only for surface colouring and patination but also for aging. These etching procedures mainly attack the steel layers in a composite pack, not so much the iron which can lead further to the forming of TEKKOTSU also on the flat sides of a TSUBA. This is another fact which supports my belief. Again I would like to mention that TEKKOTSU can be seen on newly made TSUBA, so there is no 'wearing-soft iron-off the MIMI' in use. If someone had a worthless (damaged) TSUBA with good TEKKOTSU tested with a Rockwell HRC device (this test would leave two small dots impressed on the TSUBA which you probably don't want to see on your genuine YAGYU....) it would be a proof. We could then state for sure if TEKKOTSU is harder or softer than the rest of the TSUBA metal. We have been dealing with this subject in an earlier thread, and I would invite Ford Hallam to let us know again his sight of the phenomenon.

The description is o.k., but the definition is not. I have researched in this matter and it is definitely not steel which is protruding from the surface of the TSUBA. Also, TEKKOTSU can be seen on newly made TSUBA, so the theory of 'wearing material off' in use cannot be substantiated. We have been discussing this subject here in the forums.

I think it is a small TSUBA standing on it's head, and it has been badly treated be someone who had no feeling for and no knowledge about TSUBA. If it had a patina, it's gone, and what remains is a Japanese YAMAGANE (or SUAKA) washer, looking indeed pretty plain...

As far as I know HAGIRE are flaws caused by tension in that area due to mistakes in forging or false handling in the quenching process. Normally the development of martensite in the HA area in the quenching causes pressure because of it's greater volume in comparison to the non-quenched parts of the blade. This leads in most cases to the blade bending backwards to form SORI. If the balance of the mass of the blade in relation to the YAKIBA is not finely tuned to the properties of the steel, the clay cover, the temperatures of the steel and the water, HAGIRE may occur.

I learned that these are the traces of the chisel when forming the NAKAGO ANA. Openings/SUKASHI were very difficult to make at these times, as the artists had no metal saws as we know them today. However, they had a kind of coping saw fitted with a steel wire. A mixture of oil and diamond powder helped to slowly cut into the metal. Finely cut lines as found in ITO SUKASHI TSUBA could be made this way. In many SUKASHI TSUBA traces of files can be found to even out the marks of the chisel. By the way, a very nice TSUBA!

Brian, have a look in the information pages. You will find that most hot stamps are found on mass produced blades. In this case you even have impressions of a vise or a clamp on the NAKAGO which you don't want to see at all. NIHONTO means traditionally forged blades, and this is in my understanding what this forum is mainly devoted to. It is generous and tolerant of Brian (the boss) to offer a war-time forum, but these blades (if machine made and oil quenched) and their mountings are simple militaria and are of no artistic value. I understand you like these blades but there is not much you can learn from it.

So the conditions are similar to those in Japan. I use TSUBAKI oil for these purposes. Unlike TUNG oil it will not polymerize and form a hard protective layer which is desirable if the wood is deteriorating. Good success!

The design you have in mind applies for new CHASEN. Old and used ones stretch their tines a little out and can appear to be almost straight. Regards, Jean

We are in a different situation today. Swords are no longer part of our official outfit, and our lives do no longer depend on the capacities to handle one for defence in real combat which in those times could occur every second. Japanese SAMURAI did not know about the scientifical background of ergonomical design we are used to apply today, but they had the experience to tell exactly how long one's KATANA had to be. So preserving an old TACHI from the ancestors was only one side, the 'every-day-carry' sword had to be fine-tuned to serve the requirement of body measurements and fencing techniques, and this could mean cutting off a piece of the NAKAGO and punching a new MEKUGI-ANA. We may regret to find a SURIAGE blade, but seen from the practical side this is comprehensible. Historical changes in Japan after 1600 may have lead to a more representative way to see swords, so there was a tendency for HORIMONO, perhaps hoping that the blade would not have to be drawn in a duel. Any material loss in a blade can of course be a structural damage with the risk of failure under extreme stress. With today's blades there is no risk of breaking as long as the sword is not excessively used in TAMESHIGIRI.

Is there a possibility to see a test page or two to get an impression of it? I would appreciate that.

It is always a pleasure for me to see the simple yet artful TSUBA of this time and it's style. One can see from the photograph how it was made! I like this one, thanks for sharing!

David, thank you for sharing! Gorgeous TSUBA, and it helps to understand the theme of mine. Yes, I would appreciate to see your other KO-TOSHO TSUBA, if you don't mind.

David, thank you for showing your UMETADA TSUBA for comparison. It is a nice one, and although burnt, it still has everything that makes a good reference TSUBA! As they were very likely not quenched and hardened, might it not be possible to restore it by just carefully removing the scale? Just a curious question. As to my TSUBA, I have thankfully received helpful input to two of them, but the KO-TOSHO seems to remain a riddle not only to me. I am still behind it and looking for information. Could it be that part of the SUKASHI was added at a later date, thus obscuring the symbols meaning? What do yo think?

Gentlemen, all these posts are very helpful for me, thanks a lot! I would never have come close to these explanations, a lot of knowledge besides swords and armour is gathered here in the forums!