Types of bo-hi on samurai katana swords
The bohi is also called the fuller or blood groove, it's purpose is to reduce the weight of a sword and produce an excellent tachi kaze (the sword wind sound) when you do training. Bo-hi blade is lighter, thus easier to balance. You can see several types of bo-hi below.
1. Bohi for shinogi zukuri, do not through kissaki, it is the most common type of blood grooves.
2. Bohi for shinogi zukuri, through to the kissaki.
3. Bohi for unokubi zukuri (Cormorant's Neck), no geometry. Such blades often added bohi to the shinogi zukuri part to them, creating a very light blade. Unokubi zukuri provides excellent balance in a strong cutting blade.
4. Bohi for unokubi zukuri (Cormorant's Neck) with geometry.
5. Bohi do not through habaki, this style bohi always for iaito, the purpose is to balance the point.
6. Double bohi, it features two blood grooves that runs lengthwise of the blade.