The forging and shaping of the katana is a delicate process, instrumental to the functionality of the weapon. Still, this Japanese sword is far from complete and may pass through a number of hands before it is deemed battle-worthy.
Polishing the Katana Blade
After the forging process, the swordsmith polishes the blade or passes it on to a skilled sword polisher to complete the task. The progression could take days or even weeks to properly hone the razor-sharp edge. A series of grinding and polishing stones are used and some of them can be valued at more than $1,000 each. Also called “water stones, these tools are often passed down through families for generations. The stones typically consist of hard silicate particles suspended in clay. As the tool is used the clay slowly wears away and more silicate particles are exposed. This supports excellent polishing quality throughout the life of the stone. Multiple sets of stones are used, with each set containing finer silicate particles to remove less and less of the steel.
Hirimono and Hi
Decorative grooves such as the “horimono” and “hi” are then added to the blade. The horimono is a carving that is specifically for aesthetic purposes and is especially common in ceremonial blades. There are a number of different designs, which may be completed by the swordsmith if he is skilled in this specific art, or it may be completed by a horimonoshi (engraver). The decorative grooves of the horimono must be carefully placed to not compromise the balance of the sword, if it is in fact intended for battle.
The hi is also known as the “blood groove.” This addition serves to make the sword lighter while maintaining its integrity. The groove can either extend to the edge of the blade or reach all the way to the nakago (tang), which is the part of the steel that extends into the handle of the sword.
The nakago is also filed to adorn a specific pattern called “yasuri”. The mei “swordsmiths name” is carved into it like a signature or stamp authenticating it to that maker. This is usually done with a chisel and hammer, but may be completed by a mei-kiri-shi who specializes in inscribing and acts for the swordsmith.
The mei is always written such that is faces outward, away from the body when the sword is being worn. The signature may consist of not only the swordsmith’s name, but also the providence in which it was created and potentially a date. It is often difficult to decipher by the untrained eye given that it is comparable to an actual handwritten signature.
After the completion of the carving and engraving, the blade is passed along to a polisher who’s duty is to sharpen and clean the blade. This serves to reveal the details of color and texture and is completed after a couple of days of work.
A metalsmith is next in line to add to the process of finishing the katana. Here the blade is fitted with the collar or “habaki” which is usually made of brass, copper or iron. It assists in keeping the blade in place.
The tsuba is also created by the metalsmith. This is the part of the katana that separates the blade from the handle of the swords and keeps the hand from slipping onto the blade. The tsuba is also called the “cut guard” because it can help to protect the swordsman’s hand from an attacking opponent. The piece is often made of iron and is decorated.
Creating the Tsuka
The handle of the katana, which is called the “hilt” or “tsuka” is made of two pieces of wood that carved to tightly fit onto the tang. Two panels of ray skin are then places over the wood. Thin strips of wood are placed at both edges of the tsuka and serve to influence the shape of the tsuka as assist in securing the silk braid overlay called the “ito”.
The art of wrapping the silk braid or “ito” around the tsuka is called tsukamaki. The wrapping process begins with the center of the length of the ito placed flat on the front side of the tsuka just behind the collar. The work extends down the length toward the butt end of the tuska with the two half-lengths of the ito intertwining and crisscrossing. This prevents the ito from being totally unraveled if a portion is cut.
The diamond-shaped openings commonly found in the hilt design are made using paper triangles (hishi-gami) to guide the process. These openings allow the hilt ornaments or “menuki” to be seen. The menuki are placed to fit in the palm for grip and originally meant to hide the “menugi” which is the peg that secures the tuska to the nakago.
Every detail of the katana is important to the swordsman. When life and death are on the line it is fair to say that each detail is more than important. It is crucial. The katana is a symbol of strength and beauty from the polished tip of the blade, through the wave of the hamon, down to the ito that wraps the handle. Each katana is as individual as its wielder and the craftsmen he trusts to create this battle-ready weapon.