The Japanese Sword

      There are few weapons that carry the same mystique as the Japanese sword.  It is forged under rites that are directly connected to Japan's Shinto religion, and labeled the "Soul of the Samurai," the Japanese sword serves as both a work of art and as a deadly weapon. For literally hundreds of years, the Japanese sword also served as a symbol of rank for the Samurai class.
         According to legend, there was a swordsmith by the name of Amakuni that created the first true Japanese sword sometime around 700A.D. Although there were small changes in the overall design of the blade during the next thousand years the actual shape of the weapon has changed very little since it was invented. 
       I do not believe that there will ever be a weapon that will fill the dual role or last as long as the Japanese Katana sword has.  Alot of that may have to do with the fact that  no one ever sees the romance of single combat anymore, we prefer to use weapons to just kill from as far away as possible.  We will never again see the likes of the men and weapons like we have for the past 1000 years. 

Making a Samurai Sword

The hardening of steel involves altering the microstructure or crystalline structure of that material through quenching it from a heat above 1,472 °F (bright red glow), ideally no higher than yellow hot. If cooled slowly, the material will break back down into iron and carbon and the molecular structure will return to its previous state. However, if cooled quickly, the steel's molecular structure is permanently altered. The reason for the formation of the curve in a properly hardened Japanese blade is that iron carbide, formed during heating and retained through quenching, has a lesser density than its root materials have separately. The katana gets its gentle curve from quenching during forging, as it is straight prior to quenching. A process of differential tempering causes martensite to form predominantly in the edge of the blade rather than the back; as the spine has lower retained lattice strain, it cools and contracts, and the blade takes on a gently curved shape.

A coating of clay mixed with ashes and a small portion of rust is applied to every surface but the edge of the blade during hardening. This provides heat insulation so that only the blade's edge will be hardened with quenching. This process also creates the distinct swerving line down the center of the blade called the hamon which can only be seen after it is polished, a katana forger's signature.

After the blade is forged it is then sent to be polished. The polishing takes between one and three weeks. The polisher uses finer and finer grains of polishing stones until the blade has a mirror finish in a process called glazing. This makes the blade extremely sharp and reduces drag making it easier with which to cut. The blade curvature also adds to the cutting power.

The katana is characterized by its distinctive appearance: a curved, slender, single edged blade, circular or squared guard, and long grip to accommodate two hands. It has historically been associated with the samurai of feudal Japan and is also known as the "Soul of the Samurai", and has become renowned for its sharpness and cutting ability, to the point that its purported cutting capabilities have reached almost mythical status.

Japanese Martial Arts

    In martial arts, no other weapon held the same status as the Japanese sword.  It was central to training.  But it had to be considering that this weapon was being carried by all warriors as was their right too.  When you look at the older schools their kata has the sword as the central element.  As the students would start to learn the staff or spear they learned to use it first against a sword.
  Regardless of whether you are learning jujutsu, aikido, or judo there is a very strong influence of swordsmanship.  Even the notorious ninjutsu was influenced by the ever present Japanese sword.  Ironically, you will find that people training in martial arts that have been influenced by the Japanese sword are unable to hold that weapon correctly.

Samurai Swordsmen

     There are tales of single swordsmen fighting and beating large numbers of enemys at a single time, however these are for the most part just tales.  The famous swordsmen Musashi, Ittosai, and Yagyu had all at one time faced several opponents  and not only survived but managed to win those encounters.  Combine theses feats with the dueling record of Musashi and you have what it is that makes these swordsmen remembered as the best in Japan's rich history.
       Most who followed the way of the sword did not realistically expect to live to an old age, and most didn't.  But the men mentioned earlier all died of natural causes despite the number of duels and battles that they had fought in.  All these men started their own schools and essentially their own martial arts.  They continued to wander the countryside looking for opponents with whom they can improve their skills.