[MS] Blade Length

The blade length is measured in the Japanese traditional unit called Shaku. One Shaku equals 30.3 cm, or roughly 1 feet (0.994 Ft.). Its sub-unit is the "Sun". There are ten "Sun" in one "Shaku", so 5 Sun can also be written 0.5 Shaku. Please note that a blade length does not include the Habaki (see pictures), but is measured in a straight line from the tip (Kissaki) to what is called the Munemachi (base of the blade), hidden under and partly covered by the Habaki. Light and standard blades are available for lengths up to 2.55 Shaku and thick/heavy blades are available for lengths up to 2.70 Shaku, owing to the alloy’s resistance. Wakizashi are available from 1.30 to 1.50 Shaku.

The Satsuma Koshirae is the only Iaito that can be manufactured up to 3 shaku. The blade being specifically designed and manufactured for extra long blade, it is not possible to manufacture it under 2. 80 shaku.

The blade length depends on your height, on your arms length and on the school in which you practice. The size table below is the official recommendation of the Japanese Iaido Federation. Women are advised to use a blade one size shorter than that of men of the same height. We also recommend for people who are not specialists (Aikidoka for example) to use a blade a size shorter than the recommendation, because it will make the sword unsheathing/sheathing easier.
Blade length is of course related to the Saya length, but note that for a same blade length, the Saya length can slightly vary.

Please also make sure to consult your teacher to check that the size table below is applicable to your school.

Please note that the size recommendation does not apply to Wakizashi as the Iaido federation does not provide such recommendations. However, we do recommend avoiding too long blades for small practitioners