Forging Craft: hand forged and polished by 13 procedures, clay tempered

Hamon: real hamon, clay tempered line

Tang: full tang

Blade style: Unokubitsukuri鵜首造,"小烏丸"

BO-HI: Double bo-hi,a long and a short one

Whole length: about 50 cm

Blade length: about 30 cm

Nakago length: about 19 cm

Weight: 346g

 

There is no hole on nakago, but we can drill it if you need. The hole will be placed randomly ,and we will not do the maintenance with the nakago,hope you can understand,thank you.

 

This blade is 100% hand-forged and hand-sharpened according to the Japanese traditional forging methods. Our differentially hardened carbon steel blades have been heat-treated, sharpened, and well-balanced. The blade is constructed from high quality carbon steel, carefully hand beaten into shape, forged, quenched before being polished by hand to a mirror sheen.

 

Before being quenched, a special clay mixture can be applied onto the blade to harden the edge and obtain different hardness on the blade. The clay mixture, was a special recipe and considered a crucial trade secret, guarded protectively by sword making masters.It would contain such things as feathers, powdered bones, grass, etc. and would be applied to the edge of the blade before being quenched. During quenching, a chemical reaction between the clay mixture and the hot steel occurs during the sudden temperature drop and carbon is fed into the blade in high amounts, creating an extremely tough edge. A clay hardened blade can only be quenched in water, thus increasing the defect rate even more.

 

Another way for clay tempering is to apply clay along the blade but let edge exposed. Thus, while quenching the blade into water, the uncoverd edge will cool down suddenly, but the rest of blade will cool down slowly. Such differential temperature change results in the different hardness of the blade. So the edge is tough enough to cut, where the back of blade is soft/flexible enough to absorb the impact during cutting. Such quenching process usually will leave beautiful wavy tempered line on the blade, as known as "homon" in Japanese swords term.

 

After quenching, the sword will be quite tough and brittle, with little flexibility. To overcome this, the blade would undergo a tempering process. The blade would be reheated to a certain temperature degree then allowed to cool naturally. The blade would be slightly less tough afterward but have a greater degree of flexibility – the art would be to perfectly balance the blade for toughness, sharpness and flexibility.

 

While it is common to find swords which have a rat tail tang (two pieces welded together), a thin tang or even no tang at all, all of our Japanese swords have a thick tang running from the blade to the full length of the handle.