Nihonto Club Japanese Sword Information Exchange

Double-edged straight sword. Ken form is most commonly seen in tanto, but longer kens also exist.

A tachi with a cutting edge that exceeds 3 shaku (91cm).

See also The Nodachi/Ôdachi web files.

A thick, curved type of companion sword of the Nambokucho Period with wide mihaba and o-kissaki.

Blades longer than 60 cm are called katana. They are worn thrust through the belt, with the cutting edge facing upward. The katana superseded tachi beginning in the Muromachi period. One distinctive style, produced in late Muromachi, is known as uchigatana. It as it's deeply curved in the upper part of the blade and is wielded with one hand.

Blades greater than 30 and less than 60 cm (12 and 24 inches) in length are known as wakizashi. During the Edo period, this was the shorter of the pair of swords worn by samurai.

The word "wakizashi" comes from waki (脇), meaning "side", and zashi (差し), whose root is the verb sasu (差す), meaning "to wear a sword at one's side".

Special terms are used for blades of unusual length:

ko-wakizashi (小脇差) - short wakizashi (between 1 shaku and 1 shaku 9 sun, 9 bu (30.3 cm to 60.297 cm))
chū-wakizashi - medium wakizashi (between 1 shaku, 5 sun and 1 shaku, 7 sun, 9 bu (45.45 cm to 54.237 cm))
o-wakizashi (大脇差) - long wakizashi (between 1 shaku, 8 sun and 1 shaku, 9 sun, 9 bu (up to 60.297 cm))

A curved sword with a blade longer than 2 shaku (~60cm). It was worn suspended from the belt with the blade edge down. They were mainly produced in Koto times. Later, many old tachi were cut down into katana. The majority of surviving tachi blades now are o-suriage, so it is rare to see an original signed ubu tachi.