Sugata (Blade style): Hand-forged curved blade with a Bohi (groove) and Chu-Kissaki (tip). Folded steel (C45 & C105W- USA: Steel 1095). 13 times folded to achieve ca. 8192 layers. Traditional clay-wrapping technique for differential hardening. There are beautiful hada (grain in steel, pattern of folding the steel) in the blade. The hardness of its Mune is ca 43° and the Ha (blade edge) is ca 60° HRC Rockwell. The blade spine is iori-mune, the edge is without Niku. (The blade has got a flat and cutting sharp edge). The blue color of the blade is the color of the steel, which is achieved by a special technique. It is not a surface-coating which might reduce the sharpness of the edge. The colouring results in better visual effects of the folded steel pattern as well as the hamon line and different hardening areas. The hada can be easily seen.