Katana Bohi Things you should know about this part


Things You Need to Know About Bo-hi

Bo-Hi, also known as Hi, is a vital part of a Katana sword. Besides creating a visual appeal, it helps to lighten the Katana. So, you should know more about this excellent part of Katana. This guide will help you in this regard.

Overview of the Bo-Hi Part of Katana

On the length of the Katana blade is a groove called the Bo-Hi. Without compromising the blade's durability, it lightens the Katana. Additionally, it slightly moves the Katana's equilibrium state towards the Tsuba. As a result, it increases the sword's cutting speed and lightness.

The term "Bohi" (pronounced "bo-hi") means “Blood groove”. It is the single or number of grooves carving into a sword's blade and extending from the tip to the base. The original purpose of this function was to help stabilize the weapon. It made it simpler to control during combat. But it also had the benefit of rendering the blade more aerodynamic, thereby improving its cutting ability.

What's the Usage of Bo-Hi?

Bo-Hi has many usages, such as maintaining balance, improving cutting ability, etc. It also serves to make the sword more aesthetically appealing.

One myth is that the Bo-Hi prevents blood from sticking to the blade which might render it challenging to control. Some even say that the swordsmiths create this groove for fluid to drain to prevent blood from dripping and making the Katana handle slippery. But these are just myths and nothing more.

In reality the Bo-Hi is strictly there to eliminate certain materials from the sword. Thus, the Hi contributed to the sword's weight reduction from a functional perspective. Besides that, the Bo-Hi groove reduces the risk of the blade breaking at its thinnest point.

Moreover, as mentioned earlier, it helps make the sword more aerodynamic, which may boost swinging power and speed. The Katana Bo-Hi increased the sword's aesthetic appeal and enhanced its intimidating appearance.

Most interestingly, the Bo-Hi is intentionally made to create a certain wind noise when swinging the katana. This is called the “Tachi-Kaze”. Not only does this make capable swordsmen appear more intimidating, it also provides auditory feedback to the user with which he can determine the speed and angle of the cut. 

What Are the Common Types of Bo-Hi?

The five primary varieties found on katana swords are the Soebi, Tsurehi, Soehi, Futasujihi and Koshibi. A brief description of each is given below:

Bo-Hi: The bo-hi, just a single groove along the blade length, is the most fundamental style of the Katana blade groove. 

Soebi: It is a thin gutter that sits beside a main gutter of the katana sword. 

Tsurebi: Just like the Soebi the tsurehi is a thinner gutter that runs beside a main gutter of the katana. But it also slightly extends to the tip of the sword. 

Futasujibi: In this type of Bo-hi the katana blade bares two gutters of the same thickness that remain parallel to each other. 

Koshiba: This bo-hi is distinctively short and is limited to the lower half of the katana. It usually comes scratched at the stem. 

In our custom katana section, you can choose different types of bohi.

Frequently Asked Questions

Will a Badly Done Bo-Hi Impact Performance?

Yes, if excessive material is removed, not if the Bo-Hi is just badly finished in appearance.

Will two or 1.5 blood grooves remove far too much metal from the Katana, rendering it too delicate?

No, the Bo-Hi will make no difference to the overall durability of the katana sword when it’s done correctly by a good craftsman.  


Contemporary martial artists who do numerous katas or demonstrations frequently prefer Bo-Hi. Thanks for reading through. Hopefully, you've found this article helpful. Have a fantastic day! Don't forget to check our katana anatomy guide here.

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