Nihonto (Japanese Sword)

Nihonto are an important part of Japanese history and culture. There are many varieties of Nihonto, but they can generally be organized into three main catagories, classified by their blade length. The traditional unit used in measuring blade length is shaku, a unit roughly equivalent to 33 cm, or 1 foot.

Less than 1 shaku is known as a tanto (dagger)
Between 1 and 2 shaku is a shoto (short sword)
Greater than 2 shaku is a daito (long sword)

There are also subclassifications denoted by the prefixes "O" for big, and "Ko" for small. For example, a katana (daito) with a length around 2 shaku would be called "Ko-katana", and a wakizashi (shoto) with a length just under 2 shaku would be called "O-wakizashi".

There is also a special classification for very long swords with a blade over 3 shaku. Such swords are called either Odachi, meaning "great sword" or Nodachi, meaning "field sword". Such weapons were usually used by foot soliders to give them an advantage of reach. Due to their extremely effective killing capability, it is now illegal to own one of these swords, except for ceremonial purposes.

Traditionally, swords were generally made by one of five different schools, known as the Gokaden (Five Traditions). These schools were located in the Soshu, Yamato, Bizen, Yamashiro, and Mino provinces, and even today very old swords can still be traced back to their place of origin through certain characteristics that were unique to each school.