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Secrets of the Samurai Sword


A samurai sword is more than just a weapon. For the ancient samurai, his swords were an extension of himself. Because the samurai relied so heavily on his swords, they eventually took on more spiritual significance over time. Is it no wonder that the samurai soldiers of old believed that their souls would actually move into their swords.


This is the explanation for the high level of care and discipline that went into the fabrication of each sword made for the samurai to use before he went into battle. These swords of old hold many secrets. From how they are constructed to the reasons for some of the features found in samurai swords, to the words used to describe them, you will come across little-known facts about Japanese swords.


How Sword Names Specify Their Time Periods

Japan has historically been divided into provinces, which are similar to the states in the U.S. Each province had its own samurai school and traditions. Not only did each school have its own traditions, they had their own trademarks. This means that the swords from each province became known for a particular quality.


Collectively, the five province schools are known as Gokaden or the Five Traditions:


º Mino School

º Soshu School

º Yamasiro School

º Yamato School

º Bizen School


During the Koto era, 19 other province schools had traditions or practices that didn’t fit in with the Gokaden. These schools also mixed several elements of each Gokaden. To differentiate them from the Gokaden, they were called wakimono or small school.


Secret of How Samurai Swords Were Made

Samurai swords were never cast in molds. Instead, the sword smith heated the steel and hammered it flat. Once this was done, the hammered steel was folded, then hammered again. Once again, the steel was folded. This process could be repeated as much as 30 times or until the sword smith was happy that he had done his work properly.


Why did he do this? He wanted to remove any air pockets that might have formed inside the steel. That air pocket would have created a week point–which would have reflected badly on the sword smith and on the samurai. By hammering and folding the steel so many times, even more strength was added to the soon-to-be blade.


Forging a Japanese sword could take several weeks or even months. Instead of being just an occupation, swordsmithing was considered to be a sacred art, involving several artisans. Even the sharpening and polishing of the sword’s blade could take just as long as the forging process took. Just as it took several smiths to make the sword’s blade, the manufacturing process of the different parts of the sword and its fittings could also involve several different artisans.


Secret of How the Sword is Strengthened


By hammering and folding, the swordsmith worked to spread the carbon elements inside the steel, along with its impurities throughout the entire blade, which increased its strength more uniformly.


To cool the heated steel, the sword smith used a technique to give the blade both hard and supple qualities. He painted onto the blade a formula of clay before dunking it into cold water. Beyond this, he painted thinner amounts onto the cutting edge, then thicker amounts of clay onto the back of the blade. By doing this, he enabled the sword’s blade to have both the hard cutting edge and the supple back.


The two halves of the blade cooled at different speeds. The skilled sword smith used this tendency to allow the blade to take its characteristic curve.


Secret of the Katana and Wakizashi Swords

Samurai traditionally wore two swords: the katana and the wakizashi. The second sword was a shorter one and both together enabled the samurai to fight on the battlefield more effectively.


The Uses of the Katana and Wakizashi Swords

The wakizashi was used for close quarters fighting and to stab and decapitate opponents. The longer, or katana sword, was used for open combat. When worn together, both swords were known as the daisho, which marked the social status and honor of each samurai.


Secret of Carrying and Drawing the Samurai Sword

The samurai would carry his daisho in several ways. The most commonly used way of carrying his sword would be with the sheath pushed through his sash. Once the sheath was placed into the sash, the samurai would slide his sword edge up into the sheath.


There was a reason for wearing the swords this way. Wearing them with the blade turned down made it more comfortable for the samurai to carry and draw his weapon while he was mounted on horseback. His armor was bulky and made it difficult for him to remove the sword from any other part of his body.


When he wasn’t armored, the samurai could easily carry his sword with the blade facing up, which made it much simply for him to draw and strike, all in one motion. As he was preparing to draw out his sword, he would turn the sheath down about ninety degrees, then pull it out of his sheath slightly with his left hand. After doing so, using his right hand, he would grab the hilt and pull the sword out while simultaneously pushing the sheath back into position.


Secret of the “Blood Groove”

Every samurai sword has a shallow groove that has been put into it. This is for more than simple decoration. Known as the “blood groove” or HI, this groove works to make the blade lighter and stronger. As swords bend, they are put under increasing stress, especially near the edge or back of the blade. The blood groove takes material away from the back, by the spine of the blade. This area of the blade is close to its neutral axis. Once the blood groove has been put into the blade, stiffer blades will be lighter. Sword blades of a specific weight will be given added stiffness.


Lore has it that the blood groove was put into samurai swords to make it easier to pull a blade from the saya or scabbard. The grooves don’t allow blood to flow more freely from wounds inflicted upon opponents. Nor do they decrease the sucking sound when the blade is pulled out of the bodies of opponents.


Secret of the Whistle and Tachikaze

Look at the placement of the blood grooves. Sword smiths placed them on both sides of the blade. When the sword is swung (called tachikaze), it whistles.


One whistle from a katana sword with a groove means that the whistling sound is coming from only one groove. Two whistle sounds indicate that the whistling sound is coming from a grove and the edge of the blade. If the samurai and an opponent heard three whistles, this meant the sound was coming from the edge of the blade and both grooves. The samurai would know then that his katana blade was angled perfectly with the direction of the cut.


Influence of the Mongol Invasion of Japan

During the 13th century, the Mongols invaded Japan several times. These repeated invasions led to a transformation of the Japanese samurai swords, due to the damage the swords sustained when used in battles against Mongolian warriors. The Mongols wore heavy, thick leather armor, which was well-able to resist the Japanese swords of that time period.


Samurais and sword smiths realized they would have to make significant changes to the design of their Japanese swords, which, up until that time, had been too fragile, easily sustaining damage during battles with the Mongols.


Some of these changes included crafting thinner sword blades with more simple temper lines. Other Japanese sword smiths decided that blades with bigger points and thicker backs were the answer to creating swords that would withstand the heavy, sturdy Mongolian armor.


Secret of the Evolution of the Katana Sword

Before the year 1500, samurai usually wore their samurai swords suspended from cords on their belts, so the edges faced down toward the ground. Beginning around 1600, more samurai wore their swords edge-up, through a sash. They paired their katana swords with shorter swords, “buke-zukuri” style.


After 1600, wearing their swords hung from cords strung onto their belts helped the samurai, especially when they were in battle and on horseback. If their swords had been allowed to hang vertically, this would have made it much more difficult to pull their swords out of their scabbards. Having the swords suspended horizontally made it much easier for samurais to withdraw them from their scabbards.


How Peacetime Affected Sword Quality

In peacetime, sword smiths had the time to create and make more artistic sword blades. During the Momoyama period, high quality swords became much more common. During one wartime period, the methods and techniques of the old sword smiths was lost. The swords made during wartime were inferior, probably because of a decline in the smith’s manufacturing abilities.


During the Edo period, which ran from about 1600 to about 1850, sword blade quality deteriorated even more. Ironically, the ornamentation on the blades was more refined during this time. This time period, known as the Tokugawa shogunate, was a period of isolationism. Japan and its leaders did not feel the need to involve itself, its citizens or samurai in the issues of other countries. Accordingly, the use of firearms and swords went down.


Master sword smith Suishinishi Masaide stated that he found the art of sword making and the swords themselves were inferior to the blades of old. He advocated a period of research by the sword smiths of the day to study and recover the old techniques. Sword smiths all over Japan heard his call and began making swords of a higher quality.


Secret of General MacArthur’s Decision on Samurai Swords

After the end of World War II, the U.S. occupying government banned the production of swords with edges, unless the person requesting the swords had a permit from the police or government. Not only were swords banned, all armed forces were disbanded.


Dr. Junji Honma, a renowned sword scholar, met with General Douglas MacArthur to request that the ban on swords be overturned. As he sat in his meeting with Gen. MacArthur, Honma showed several samurai sword blades to MacArthur, who quickly learned to identify which blades held potential as a weapon and which had only artistic value. After this meeting, Gen. MacArtthur amended the swords ban so that swords that held artistic merit could be preserved by individual Japanese. Blades that were clearly weapons were kept under the ban.


During the ban, Japanese sold many of their nihonto swords (wakizashi, katana, nagamaki and tachi) to American soldiers stationed in Japan during the American occupation.


Because of the American occupation and the regulations put into place by the American administrators, the production of samurai swords nearly ended. Even so, a few sword smiths throughout Japan continued making their swords. Dr. Honma became the founder of the Japanese Sword society. This society’s mission was to preserve the old manufacturing techniques and blades that had been made by sword smiths. As a result of the formation of this society, sword smiths continued their swordsmithing, helping to rediscover and re-establish the old techniques.


Secret of the Daisho

Ancient samurai wore a wakizashi sword with the katana sword as they went into battle. The wakizashi was shorter than the katana, with both swords serving their own purposes. These swords were worn by the samurai and, when they were worn in combination with each other, this was known as “daisho.” Daisho stood for the samurai’s personal honor as well as for the social power they held in Japanese society.


Even though the samurai wore his two swords together, they were not necessarily forged at the same time by the same sword smith. Instead, the samurai bought two separate swords, often made by different smiths. If a samurai was fortunate enough to own a daisho composed of two swords that had been forged and mounted as a pair, he would have been a rare samurai with a rare pair of swords. These swords would have held a much higher value, especially if they still had their original mountings.