♣ Introduction of Visit “Japan Sword Museum”
東京・渋谷にある1968年に設立された「刀剣博物館」は、現存した日本の美術刀剣と装備品を豊富に収集し
一般公開展示している。その中には国宝級のものも数多くある。日本の「刀」は武士の権威を示す武具であったが、同時に日本の独特の美意識と優れた職人技術「匠」の粋を示すものである。また、これを製作してきた「刀鍛冶」の技術は、歴史的に地場の鉄鋼加工産業の発展にも貢献してきたといわれる。こんな意識から、今年３月この博物館を訪ねてみた。このレポートは、このときの印象を記したものである。
The unique museum, “Token Museum” (Japanese Sword Museum) in Shibuya, Tokyo, is attracting many people these days. This museum was established in 1968. I visited this sword museum in this March. In the museum, the hundreds of
precious swords and ornaments of the national treasury class are broadly collected, stored and displayed. Japanese sword is well known by its aesthetic and historical value. But, it’s also reflecting Japanese sensibilities and excellence of craftsman’s skill. After visiting I really felt that the Museum was the best facilities showing up Japanese subtle artistic sense and craftsmanship. This is a report on the impression of my visit attached some additional materials.
Refer: home Page: http://www.touken.or.jp/museum/
++++++++++++++++++++++++++
♣ The overview of Sword Museum
The unique museum, “Token Museum” (Japanese Sword Museum) in Shibuya, Tokyo, is now attracting many people. This museum was established in 1968 for the appreciation and preservation of Japanese swords by NBTHK (Society for
Preservation of Japanese Art Swords).
Japanese sword is well known by its aesthetic and historical value as it is reflecting Japanese sensibilities and excellence of craftsman’s skill. In the museum, the hundreds of precious swords and ornaments are collected, stored and displayed. So that it is regarded as the biggest collection of Japanese swords in Japan.
♣ Real Value of Japanese Sword
Japanese sword was formerly an essential armor of Japanese warrior (“samurai” class) in the Edo period (17c-19c), but also showed the identity, glorification and significance of the samurai class. Currently its antique value is appreciated much around the globe, and loved by Japanese people widely. 
In the addition, the sharpness and delicate beauty of the sword’s slim body is highly admired as 
the first class art product in the world. On the other hand, this Japanese superior forging technology, embodied in the sword, is recognized to have contributed to promote metal processing industries in Japan. Then the Japanese sword-making technology became the industrial heritage due to its great contribution to form the iron processing industries..
♣ Sword-making Technology and Current Steel Production
Of course, the development of the modern steel
industry after the Meiji era was mostly depended on the import technology from the West, but the basic iron-processing manufacturing skills was nurtured through the traditional craftsmanship, which exemplified in sword
making, such as the “Takumi” (Japanese style craftsmanship) of refining, forging, burnishing and shaping of iron technology.
♣ Special Exhibition of “Blade Making Style”
In that sentiment, I visited this sword museum in this March. When I visited, 
the Museum was coincidentally holding the special exhibition of “Transcend of Sword Blade Shaping in 1000 year period” which tried to show changing “Hamon” technology. Generally the 
Japanese swords characterize by the hard but sharp blade, and the specific hallmark is engraved in the body which generated in the producing process. This pattern is called “Hamon” which signifies the quality of sword, tough and sharp of blade, as well as it symbolizes the beauty of Japanese sword as an aesthetic armor. This special exhibition seemed attracting many people , so as bunch of visitors were visiting to observe them, including foreign visitors.
Generally Japanese sword said to be manufactured in pursuit of the three conditions, like “Never break, Never bend, and Well cut”. Usually the iron products have a feature of tough and hard, but holding frangibility under the strong pressure, because it is containing many carbon molecules in the body. On the other hand, the sword should fulfill the strict condition of toughness while keeping non-frangible feature. To solve the problem, Japanese swords have been applying the ultra-elaborate method, in which the comparatively softer blade “Shintetsu”, containing rich carbon, are elaborately wrapped with the hard steel by reducing carbon. Actually this unique “Hamon” engraved in the blade is reflect this special manufacturing process.
♣ Excellent Craftsmanship of Sword-smith
The museum is very much proud to exhibit the numerous first class Japanese swords of national treasure class. The sword was shinning by subtle luminary beam in the showcases. I was stunned and fascinated with the sword’s beauty which experienced hundreds years of time.
They were splendid work that never let people feel such a long age. I was greatly impressed by the outstanding ability of “Takumi” (masterful Technic) of sword-smiths. In addition, in the museum they displayed the huge collection of sword accouterments, like sheath, guard, and grips. They were also really superb, and hinted the artistic culmination of skills which combines functionality and aesthetic values.
♣ The Sword Technology promoted Japanese Local Industry
In the meantime, the forging technologies of “Takumi” were not limited in the sword making, but influenced much in the technology development of local industry of blacksmith and metal processing manufacturers in Japan. 
The technological skills were widely used in the making of popular cutlery, farm equipment, cooking utensils and other daily metal products from the early time. So that such technologies have been accumulated among the manufacturers of various locations in Japan, and t contributed to form the industrial clusters of metal processing manufacturing, like the cutlery of “Seki” in Gifu, kitchenware of Niigata’s “Tsubame” and “Sanjo”, and other regions.
♣ Miracle Technology of “Tatara” Iron-making
As a matter of fact, even though the technology “Tatara Iron-making” process, which used specific sand iron as a raw materials 
for Japanese sword, was already becoming the outmoded technology, but the “Japanese sword” itself is never able to produce without “Tamahagane” (treasury steel) method by “Tatara”, no other than adopting of this traditional methods.
“Tatara” production method is defined that the specific iron sand and charcoal are put into a traditionally layered furnace, then the ore is burned under the strong heat by sending the wind by “Fuigo ”(bellows) to make up the steel iron.
♣ Nitto Tatara Project and Hitachi Metals
Then the process is now designated as an important industrial heritage valuated its precious historical technology. In addition, this traditional method is reported to be linking with the important modern steel making technology in Japan, such as the products like strong magnet steel “KS Steel” and the Ultra-invariant Steel which were firstly produced by Japanese engineers in the early 20c.
Hitachi Metals Japan was aware of the importance of the succession of such traditional 
advanced technology and set up the “Nitto Tatara” project (Site of Selected Conservation Techniques) in Yasugi district, Shimane Pref. in 1974 under the request of the Sword Museum. Under this initiative, the engineers of Hitachi Metals Group, is now developing the strong steel tools, heat-resistant steels, stainless steels as the brand of “YSS Yasuki-hagane” and wins high reputation.
♣ Impression of my Visit
This visit were actually purposed to observe and appreciate of artistic value “Japanese 
sword” , but I think I could learned a lot about the technology base behind the Japanese sword making, and studied a bit how the traditional techniques have developed and had been linking with the modern metal processing industry in Japan. I thought the museum was one of the recommendable facilities to be worth to visit for 
foreign visitors as well as Japanese young people.
I myself, albeit in the distance, hoped to be able to visit the “Nitto Tatara” in Shimane someday, where exists the Japanese traditional iron-making preserving site and current figures.
(end)
Reference：
- http://d.hatena.ne.jp/settu-jp/20120217/1329439894 神話としての日本刀 鍛冶と鋼
- http://tojiro.net/jp/guide/material_japanese_sword.htm 日本刀と包丁
- https://www.facebook.com/techon.fb/videos/864297163642362/
- http://www.film.hitachi.jp/movie/movie739.html
- 図解・日本の刀剣 久保恭子 （東京美術出版） 2015
- The Art of the Japanese Sword; as thought by the experts, by K.Kawachi & M.Manabe, Ribun Shuppan, 2003
- ビジュアル版 日本の技術１００年 (2) 製鉄・金属, （筑摩書房1988）