ROKUJURO

Mauro, I am not one of the experts, but I also found these mistakes, which led me to make a critical comment about the book. For my education, I need good pictures of high-quality items and a reliable text. This is the reason why I was not enthousiastic. For an amateur author, it is just pointless to write a book about a very specialized subject like TOSOGU without the help of real experts, be that in the subject or in language/translation.

Thanks for sharing, but unfortunately, the catalogue is not very educational.

Jos. I have a problem with your name. Once you have signed 'Markus', now it is 'Jos.'. Why don't you just adapt the way everybody does it here on board? Give us a full first name to address you, that is all - it won't hurt! The stuck HABAKI (not hakabi) should be removed, the more as you have tried water and soap. Did you really try hot water on the HABAKI? It won't damage the blade if you dry it immediated after the treatment. Did you try WD 40, a bad smelling but efficient lubricant? You can also try with wooden tools, and in my experience this works best. Keep safe at all times using self-adhesive tape to mask the cutting edge and to protect your fingers. With a chance of the blade being a GENDAI-TO, it is worth the effort! Good luck!

Dave, I think they are, following the data from OMURA: The chemical components of a Kōa-Issin sword Carbon Manganese Silicon Phosphorus Sulphur 　 Skin steel 0.57 0.05 0.17 0.018 0.003 　 Core steel 0.23 0.15 0.21 0.020 0.008 In his article he mentions even the absence of titanium, so this steel seems to be quite 'pure' which corresponds to low-alloy. High-alloy steel with considerable amounts of alloying components to enhance the properties would not allow quenching in water. The meaning of low-alloy carbon steel can be found here: http://www.totalmateria.com/articles/Art62.htm

Maybe I should have said it using Japanese terms: If you post photos, please show them tip (= KISSAKI) up! The HABAKI should come off with a little, but not too much force. You can read about methods here in the forums as the problem is not especially new. In most cases, crud or corrosion lead to a blocked HABAKI, so it is important to remove it to clean underneath (carefully and not with metallic tools). Please sign all posts at least with your first name plus an initial so we may address you politely. It is a rule here. It is easy to mark it in your profile so it comes up automatically with each post.

Markus, are there any stamps on the NAKAGO? (photos always tip up! No HABAKI!) They could help to identify the blade as SHOWA-TO or GENDAI-TO.

John, I have looked that up to be sure. The 'normal' hardness scale of Rockwell C ends at 68 for low alloy carbon steel. OMURA's data are not Vickers or Brinell either, so I have my doubts about his figures. My knowledge is that a hardness (Rockwell C) of 60 to 62 in the edge of a blade combined with a body hardness (measured at the MUNE) of 48 to 52 was measured in KOTO as well as in later blades. OMURA's text suffers a lot from translation problems, so I don't know for sure in some parts what his sources were and what he meant to express.

The photos do not show much of the blade. The tip and the tang (NAKAGO) without HABAKI are especially important for identification. As Stephen wrote, parts and handle wrapping are giveaways for non-Japanese copies. Please sign all posts with your first name plus an initial, as is requested here on the board.

John, is there any evidence of the hardness you mention? Carbon steel goes normally up to max. HRc 66 if it has about 1.5% of C.

Nice, but the tiger has probably a tooth problem,

Sorry, but that's all I was able to identify! There are some experts here who will know the rest!

KANEMOTO?

Ken, you are right. I should stay away from the computer when it's too late....(Corrected)

I think the key to all this breaking risk discussion is impact stress distribution. A sword blade looks to be a mechnical unit, but its composite construction does not allow to predict the performance as if it was just one piece of hardened tool steel. Looking only at the HAMON is way too selective for statements of resilience, rigidity, or durability. HOSO SUGUHA is not necessarily the "best" HAMON for all purposes. If we remember that martensite (which forms the YAKIBA) has a bigger volume (= lower density) than the ferrite/pearlite steel (corrected after a remark from Ken) of the blade's body, we understand that the cutting edge gets under pressure in the YAKIIRE process which to a great extent causes the SORI of a blade. ASHI are said to act as 'shock absorbers' in this risky stress zone, so there is no clear technical preference given for SUGUHA in my view. The same should apply to HITATSURA then. A while ago we had a similar discussion about statistics of broken blades. If i am not mistaken, it was based on research made by SUISHINSHI MASAHIDE. If memory still serves, very wide 'fancy' HAMON of SHINTO blades had indeed a higher risk of breaking, but as there were no longer occasions to use blades in military actions, weaknesses showed up mainly in TAMESHIGIRI. The problem is that we do not know much about the 'inner' construction of these blades, so that we cannot compare the testing results scientifically with, say, KOTO blades.

Robert, it is difficult to say by photos if the cannon is forged. It looks like iron and I think it is cast. I don't believe the decoration was done by heating up the whole piece and then the obviously carefully chosen floral and other (TOMOE) motives were hastily imprinted. They look like made with a chisel. If you cannot buy a projectile, you could have one made as copy to complete the whole. The head might contain some combustible or even gunpowder.

Erwin, it is not only the condition of the NAKAGO but also the photos that makes reading the MEI so difficult. Ask the owner of the blade to brush the NAKAGO gently with his wife's toothbrush and let him shoot some well focused photos from above with light from the side. Deciphering the MEI will be probably easier then. The age can be related sometimes if the maker is clear, but to help we should have more data of the blade and a lot of clear photos of every detail. And in terms of quality, age is not important.

John, why not, if you are a trained specialist in this field and leave the blade untouched. Everything else depends on the condition of the existing parts. Altering valuable parts should absolutely be avoided.

John, I like that TSUBA, it is a nice one in my eyes! On the photos it looks coated indeed, but you are the one to find out! Give it a try with Acetone or a similar solvent. The coarse surface is a result of etching/pickling before making the inlay, I think. Perhaps this was an individual patination technique used by this TSUBA maker. It has nothing to do with TEKKOTSU. There is a lot of mysticism about TEKKOTSU. A fact is that acids will attack hard carbon steel first, so protruding particles will likely be iron, not steel! Concerning the inlay technique: I have read that HIRA ZOGAN is found on older HEIANJO TSUBA, while the more protruding TAKA ZOGAN hints to later production, but I don't know if that is correct.

Mark, please put the photos upright and and also show the full NAKAGO without HABAKI. That will facilitate reading the MEI!

Valuable readings! Thanks Peter for pointing this out!

Normally HIRA-ZOGAN.

Ken, I am not sure! But the damage of the brass is somewhat strange and not typical. An inlay piece might fall off as a whole, but it should not be damaged partly by rust, I think. On the other hand, Ford is the man to comment competently on this subject,

John, the problem is not only the photos but also the condition of your blade. The HAMON may be visible, but I don't see HADA, NIE or NIOI. YOSHIMICHI is one of the many famous smiths who were faked a lot, so it may be a good idea to compare with authenticated swords like http://www.aoijapan.com/img/sword/2014/14523-2.jpg. On the other hand your blade looks like a solid and traditionally made one, so perhaps a 'window polish' might help to identify it.

Ken, what we see is heavy corrosion, but this may well have been accelerated by a fire, I think. If we look at the SHINCHU, it is also damaged in places, but rust would not have affected it. The melting intervall of brass is roughly between 950 and 1.000°C, so a damage by fire is likely.

Steve, but that's about all you can say about it, remaining polite.