Bo-Hi VS. No-Hi Blade - Parts of a Japanese Katana
What do you think are the advantages and disadvantages of bo-hi or no-hi of a Japanese Katana? Do you think whether or not to have it with bo-hi?
A bo-hi (also known as a 'bohi','hi', 'fuller' or 'blood groove') is the groove in the blade located just under the spine that helps to reduce the weight slightly without major sacrifices to its durability. A bo-hi blade can be 20% to 35% lighter than a No-Hi blade without any sacrifice of strength or blade integrity. The more weight that is reduced will in turn create a faster blade and move the balance point closer to the wielder. The lighter the blade and the more balanced towards the hilt it is, the less powerful its cutting action is and it is ever so slightly less durable. The bo-hi sword felt better but is at an disadvantage when it comes to lateral strength, it is not very suitable for hard targets like bamboo.
A blade without bohi of course will take on thicker targets with less strength needed from the user compared to the bo-hi. No Hi makes an affordable sword that will hold up well to cutting practice.
Japanese swords are often forged with different profiles. There are many styles of hi out there, but the general purpose remains the same: removing steel from the blade to reduce weight. The main difference is that a blade without bo-hi is a little heavier and has a more forward balance point - giving it more power, but making it a little less graceful. Both bo-hi and no-hi can cut very similar targets if both are properly made. Having a Bo-Hi or No-Hi blade, it depends on your training style and preferences, what you like depends on you.