32| Japanese swords after WWII

While I was growing up in Azabu and Mita in Tokyo, and later in Kamakura, my father was heavily involved in a Japanese sword society called “Nihon Bijutsu Token Hozon Kyokai.”   At that time, the head of the organization was Dr. Honma and Dr. Sato. 

Initially, Dr. Honma and Dr. Sato were at the Tokyo National Museum’s sword department in Ueno.  Later, a separate Nonprofit Organization for the Japanese Sword Museum was built in Yoyogi in Shibuya.  Though the address was Yoyogi in Shibuya, it was like almost in Shinjuku.  To build this Museum, my father, Mr. Watanabe (owner of the Wataki, an apparel company), and Mr. Suzuki Katei (owner of the construction company) were heavily involved.  Those two friends used to come to our house all the time (literally all the time) and stayed hours talking and gossiping.  At present, the Museum was moved to Sumida-Ku (Sumida Ward), Tokyo, near the sumo arena in Ryogoku.  Refer to the map at the end.

Dr. Honma and Dr. Sato, who used to come to our house in Tokyo and all other people involved, were deceased many years ago, but they were in their prime time then.  I am talking about the late 1960s to 1970s.  I was in my teens, then. 

Many people told me that Dr. Honma and Dr. Sato, and a few more prominent people visited General MacArthur’s headquarter during the occupation after World War II, and they convinced MacArthur that the Japanese swords were not weapons but art objects.  They did so because MacArthur ordered all Japanese to turn in their swords and forbade them to own one.  After a great effort, Dr. Honma and  Dr. Sato changed MacArthur’s mind.  Yet, many swords had already been turned in at Akabane (a place in Tokyo), though some people hid valuable ones.  Those swords turned in are called Akabane sword.

A huge number of swords were taken by American soldiers and brought to the U.S. as a souvenir from Japan.  Those soldiers didn’t know if they took a valuable one or an ordinary kind.   Approximately 25 years after the war, in the late 1960s and 1970s, Japanese sword dealers went to the U.S. and started to buy back many Japanese swords.  I have a few sword-dealer friends who did that.  They advertised in local newspapers that they would buy Japanese swords.  As you can imagine, many swords were in bad shape.  Some people had used the wrong chemicals to take the rust off.  Only a few were recovered in good condition. 

Among those recovered, one of the very famous missing National Treasure swords was found by Dr. Compton.  He was the chairman of the board of Miles Laboratories in Elkhart, Indiana.  Miles Laboratories was a pharmaceutical company that produced many kinds of products, including Alka- Seltzer.  He had good knowledge of Japanese swords.  When he saw this sword in Atlanta’s antique store, he realized it was not just an ordinary sword.  He contacted Nihon Bijutsu Token Hozon Kyokai (日本美術刀剣保存協会) for consultation.  During the process, my father became a good friend of his.  My father and I visited his house several times, and they visited ours back and forth.  Dr. Compton returned this sword to the Terukuni Shrine (照国神社) in Kagoshima prefecture without compensation.  The story of Dr. Compton continues in the last part of  Chapter 44 Part 2 of — 11 Ikubi Kissak (猪首切先).  Japanese swords dealers bought and took many swords back to Japan; still, it seems like there are many Japanese swords in the U.S.

Nonprofit organization: Nihon Bijutsu Token Hozon Kyoukai ( 日本美術刀剣保存協会 )      1-12-9 Yokozuna Sumida-Ku Tokyo Japan   130—0015                                                 Tel: 03-6284-1000                                                                                            


34 bigger train map (1)



  • “Nihonto no Okite to Tokucho”  written by Honnami Koson.   Issued by Bijutsu Club Tokenbu  
  • 日本刀の掟と特徴 本阿弥光遜著 美術倶楽部刀剣部発行


  •  “Sano Bijutsu-kan Zuroku”  written by Sano Bijutsu-kan.  Issued by Sano Bijutsu-kan 
  •  佐野美術館図録 佐野美術館著 佐野美術館発行


  •  “The art of the Japanese Sword” written by Yoshindo Yoshihara , Leon & Hiroko Kapp.  Issued by Paolo Saviolo  
  • 日本刀美術 吉原義人,リーオン ひろ子 キャップ著  パオロ  サビオロ 発行


  •  “Shousetu Nihonshi” written by Keigo Mochizuki & Kunihiko Fujiki.  Issued by Yamakawa shuppan (High school text book by the Ministry of Education)
  • 詳説日本史 望月圭吾, 藤木邦彦著 山川出版発行    文部省検定済教科書


  •  “Token no Mikata” written by Yuichi Hiroi.   Issued by Daiichi Hoki Shuppan Kabushiki Kais
  • 刀剣のみかた 広井雄一著 第一法規出版株式会社発行


  •  ‘The sword of Japan” written by Joseph W.Bot.  Issued by ID 13996126 www.lulu.com
  • 日本の刀 ジョ‐ゼフ ボット著


  •  “New Explanatory Diagrma of World History” written by Hamashima Book Editorial department.   Issued by Hamashima book   
  • 新詳世界史図録 浜島書店編集部著 株式会社浜島書店


  • “New Nihonto Koza”  written by Dr. Junji Honma & Dr. Kanichi Sato.  Issued by Yuzankaku shuppan Kabushiki kaisha
  • 新版日本刀講座 本間順次,佐藤貫一著 雄山閣出版株式会社発行


  • “Nihonto Zenshu”  written by Dr. Junji Honma & Dr. Kanichi Sato.  Issued by Tokuma Shoten 
  • 日本刀全集 本間順次、佐藤貫一著 徳間書店発行







31|Sword Making Process

7 Kamakura timeline

As a part of the sword study, it is necessary to describe the process of making a sword. This chapter explains only a very basic procedure of sword-making.  It is a simple outline of the sword-making process since I lack expertise in the field. 

When I was small, I used to see the process of metal being heated up in the furnace in my father’s factory.  He owned a machine tool company and a forging factory.  It was fascinating to see the metal was heated up, taken out of the furnace, pounded by two men, then put back in the furnace, and pounded again and again.  To this day, I can still remember the exact color of the metal when it should be taken out of the fire.  That was a strange thing to learn for a small girl.  Not only that, it was dangerous for children to be close to the furnace when the metal was being heated.  But those days, people’s idea for safety was different.  I think the factory workers enjoyed seeing my brother and me being so impressed, so amazed, and regard them as heroes.  We kept going to the shop until my father moved the factory to a bigger place.  Today, I would never allow my grandchildren to be near a furnace.

The sword-making involves very many detailed processes, and each swordsmith has his secrets. Anybody interested in more detailed explanations, please refer to a book written by a famous swordsmith, Mr. Yoshihara Yoshindo, and a DVD made by his son. Their information is below.  Mr. Yoshihara’s book is sold on Amazon.  DVD is sold on Japan Amazon.  DVD may be necessary to go through the proxy service; Zen Market since it is sold on Amazon Japan.

Book: The Art of the Japanese Sword —–The Craft of Sword Making and its Appreciation by Yoshihara Yoshindo, Leon and Hiroko Capp      Published by Saviolo Edizioni

 DVD:  Katana/On Ko So Shin (温故創新)——-Katana project by Yoshihara Yoshikazu (吉原義一).  Use proxy service-Zen Market, since only Amazon Japan sell it.

Tamahagane (玉鋼)

In the old days, the early sword-making time, swordsmiths extracted iron from iron sand and refined it by themselves for sword material.   By the Kamakura period (refer to the timeline above), ironmaking was done by separate entities.  Swordsmiths buy iron called “Tamahabane” from ironmakers.  “Tamahagane” is the essential part of sword-making.  “Tamahagane” is the iron made with the Tatara process, a unique Japanese smelting process.

32 Tamahagane 2

Tama-Hagane from Mr. Yoshihara

Kawa-gane (側鉄) and Shin-gane (芯鉄 )     

The Japanese sword is made from steel of two different hardness.  Kawa-gane is for outer steel.  Shin-gane for inner steel.  Kawa-gane is harder steel, which contains about 0.6% carbon contents.  Shin-gane is softer steel that has about 0.25% carbon content. Japanese swords are made with softer steel inside, wrapped around by harder steel, this way it is hard to bend, and hard to break.

Kawa-gane (側鉄: outer steel) ——– Shita-gitae (下鍛: Base forging)

Heat a block of Tamahagane  Hit with a hammer and make flat pieces While Tamahagane is still hot, quench in water quickly Break into small pieces.

Separately forge a rectangle plate with Tamahagane  Connect this plate with a handle or a lever to create a Teko  Stack up the previously broken metal pieces on the Teko carefully and closely32 Pile up drawing

 Cover the stacked up Tamahagane with ashes and clay for protection Heat this in the furnace Take it out from the furnace and hit with a hammer Repeat this process many times to stretch out Tamahgane about twice as long.

While Tamahagane is still hot, make a notch in the center and fold in half Continue the same process of heating up, hammering to stretch, and folding half (widthwise and lengthwise alternatively approximately 6 or 7 times depending on the original carbon level in Tamagahane).  This process reduces the carbon content to the desired level.

32 folding drawing

Kawagane (側鉄: Outer steel) —– Age-gitae (上鍛: Finish forging )

At the end of Shita-gitae, chisel the block of Tamahagane so that it can be separated into two or three sections Quench in water Cool down Break it into pieces along with the markings Combine these pieces and repeat the heating, hammering, and folding processes.

Usually, the folding process is done 6 to 7 times for Shita-gitae (base forging) and 6 to 7 times for Age-gitae (finish forging).  Total 12 times or so depending on the original carbon contents in the Tamahagane used.  This process is for Kawa-gane (側金)

Purpose of heating hammering and folding

  • Each time the heating and folding process is done, Tamahagane loses carbon content.  For outer steel, the ideal carbon content should be approximately 0.6%.  If the carbon content is too high, steel is hard, and as a result, the sword can crack.   If it is too low, the sword will be too soft and can bend.  Swordsmiths judge by their eyes to determine the right amount of carbon content. This is the professionalism and the art of sword-making.
  • Removing slags and impurities from Tamahagane.
  • Each heating and folding processes create many layers of thin steel that create the Ji-hada pattern (surface patterns like wood grain, burl look, straight grain, or a mixture of those)

Shin-gane (inner steel 芯鉄)       

Shin-gane is the inner metal that is softer steel with less carbon.  By having softer inside, the sword has flexibility.  Having hard outer steel with higher carbon with softer steel inside prevents the sword from cracking or breaking. To make the Shin-gane steel, mix softer steel with Tamahagane.   Repeat the same process as Kawa-gane.

Tsukuri  Komi (造り込み) Sunobe (素延 )

Wrap the Shin-gane with the Kawa-gane, then weld two pieces together by heating, hammering, and stretch out to make a steel bar.  There are several ways to wrap the Shin-gane, but the most common way is called Kobuse (甲伏). The illustration below is the cross-section.

32 Kobuse drawing

Sword Micro (3)

The above photo (taken by my husband) shows a cross-section of a sword.  Many years ago, a member of our sword club gave us a very rusty, damaged sword.  My husband cut the blade and took the micro photo of the cross-section.  This sword has a more complicated construction than the usual Kobuse method.  It looks like it has 3 (4?) different hardness of steel.  This sword seems it was once one of the top swords made by a top sword-maker.

Hizukuri (火造 )

Hizukuri is to make the final shape of the sword from Sunobe by heating and hammering.  At this point, Ha (cutting edge) gets thinner, the Shinogi side gets higher, and it starts to form a sword’s shape.

Arashiage (荒仕上げ)

This process is rough finishing.

Tsuchitori (土取)

Mix clay, pine tree ash, ground stone, and water.  Coat the sword with this muddy mixture.  Scrape off a thin layer of the mix a little around the hamon area, then dry out.  By doing the Tsuchitori process, hamon is created, and cutting-edge hardens at the same time.

Yaki-Ire (焼入れ)

After the muddy paste is dried, heat the sword evenly in the furnace.  Judging by the heated sword’s color, pull it out from the furnace, quickly quench it in the water. Usually, this process is done after the sun goes down so that the swordsmith can see the color of the metal and can judge the temperature of the heated sword more accurately. This is the most crucial process since all the work done up to this point may be ruined if he fails to judge the heated sword’s precise color, water temperature, and quenching timing.

The final process is to send the sword to a polisher.  The polisher called Togishi polishes and sharpens the blade.   He brings out the beauty of the surface and the sharpness of the sword.  This completes the whole process of sword-making.  Every step is essential, but the polishers’ final process is as important as the rest of the work.