It is a type of Tachi and can also be called " Taichi Black Woodgrain "(no-dachi).
The length of the Tachi knife is longer than the average samurai sword. In terms of real knife, blade up to 90 cm called the big Tachi knife,
it is quite a huge weapon compare to the Japanese average height of 150 cm to 165 cm. The big Tachi knife is usually carried in the back,
but if more than 180 centimeters of people will wear in the waist.
Usually the literature is Tachi knife refers to the blade more than 150 cm and 90 cm or more is called no-dachi knife.
But ordinary people are called a large knife is Tachi knife, and the no-dachi knife as another name.
According to the user's height comes different ways to use.
The blade body 810mm
The diameter of handguard 90mm x 88mm
The thickest of blade 21mm
The thinnest of blade 9mm
The thickest of back blade 13mm