Purification by Fire and Water
Last time, I explained the processes as far as tsukuri-komi. This time we will continue
from the sunobe process.
Sunobe –The completed tsukuri-komi billet is now returned to the forge, heated andgradually hammered out to length in the form of a long bar.
Hi-zukuri—This process is performed only using a small hammer. The long square bar
is beaten into the shape of a katana forming the mune (spine), shinogi (ridgeline) andcutting edge. The important task of making the point section (kissaki) is called kissaki
no uchidashi. First, the tip of the sunobe is cut off obliquely. Then, with a small
hammer, the cut edge is forged back on itself until it is in line with the spine. This canbe seen in the hada of the completed blade. This is so that the cutting edge continues
smoothly through the point section. Hada is the visible grain in the steel formed by thefold-forging process. There are various patterns such as ayasugi (cedar tree), itame(wood grain), masame (straight grain) and so forth. It has been compared to a woodgrain pattern. For example, carpenters do not work against the grain of the wood. This
also applies to swordsmiths, in that the grain must appear to run smoothly.
The shape of the blade formed during hi-zukuri can also determine the period ofmanufacture. The shape of the kissaki can also help to determine the period. In addition
to shinogi-zukuri (ridgeline contruction), there are also other forms such as hira-zukuri(flat).
Next is tsuchioki (tsuchitori), the clay application process. The material used fortsuchikoi is made from a combination of clay, charcoal dust, and ground whetstone
mixed in water. First, a thin layer is applied to the whole blade, followed by a thicker
layer along the back edge. This controls the cooling rate of the different parts of theblade at the quench. The thinner layer of clay along the cutting edge causes that part ofthe steel to become hard. The place where different clays meet produces a dividing line
between the softer and harder steels called a hamon. By using the clay, the smith canalso determine the shape of the hamon.
Next, yaki-ire. This is another popular image of swordsmithing. Once the clay has dried,
the blade is put back into the fire. Temperature-controlled by a traditional bellows calleda fuigo, the fire is brought up to 700-800 degrees. It is imperative that the temperature iscorrect. If a mistake is made in the temperature in this final stage, the condition of thesteel will deteriorate. Additionally, the temperature must be the same along whole
length of the blade. If this last process is not performed correctly, all the previous
processes will have been a complete waste of time.
Yaki-ire takes place after sunset. Why is this, you may ask? This is because theswordsmith has to judge the temperature by the color of the heated steel. This is a test of
the swordsmith’s experience and intuition. When he feels the blade is ready, at thatexact moment he must plunge the red-hot blade into a trough of water. As the hot steel
is quickly cooled in the water, it makes a sizzling sound and a cloud of smoke fills theforge. Unlike the forging process, the swordsmith only gets one chance at success when
performing yaki-ire.
The temperature of the water is secret to each school. There are legends of smiths trying
to discover the water temperature used by famous smiths and getting their hands cut off!
The carbon content of the blades and temperature of the water used for quenchingdiffers within the various traditions of swordmaking (Bizen den, Soshu den, etc). In
actual fact, there is no predetermined temperature. It is probably around 30 degrees(known as hitohada in Japanese—body temperature).
This stage is when the familiar curvature of the Japanese sword is induced. The steel’s
differing carbon contents display different qualities when cooled quickly. The cuttingedge becomes hard, whilst at the same time the softer steel induces curvature and retains
durability. These qualities can be controlled somewhat by adjusting the cooling rates
and the temperature of the water. As with variable temperatures suitable to differentsteels, each swordsmith has a preferred moment of quenching. The smith can ascertain
if he has been successful or not by the sound of the heated blade entering the water andthe way in which the smoke rises.
With only the refining work remaining, the main production process is completed. Until
now, you were probably unaware of the importance of the fire and the water.
Many old swords from sword making towns, such as Osafune in Bizen province(present day Okayama prefecture), are ranked as National Treasure or Important
Cultural Property. There are also many swords made by the same smiths that do notattain these standards. Why is there such a gap in the workmanship of the same smiths?
This is because the Japanese sword undergoes a baptism of fire. Our ancestors believedthat even though the sword is produced by man from natural resources, the fate of its
completion is decided by the gods.
Japan also has an indigenous lacquerware. However, lacquerware production iscontrolled at every single stage by man, and therefore does not obtain godliness. Eviland impurity are removed on a level where human intellect cannot reach, by passingthrough fire and water. This is the basis of the shinto purification ceremony. 
A brief explanation of the finishing stages.
Once quenching is complete, the curvature of the blade is adjusted and it is roughly
filed into shape. Gradually finer stages of filing remove any distortions. This is calledkaji-oroshi. Put simply, it is the foundation before applying make up. Next is kaji-togi, arough polish by the swordsmith on a whetstone to bring out and check the quality of thehamon. It is then passed to a professional polisher.
Next is nakago-shiage, the finishing of the nakago (the part that is inserted into thehandle or tsuka). The shape is refined and the hole for the bamboo retention peg isdrilled. After this, the tang is filed to grip the inside of the handle. The filing patterns
vary from smith to smith.

Lastly is mei-kiri. The swordsmith inscribes his name into the tang using a small metalchisel type tool. T achi and katana (uchigatana) are worn with this inscription facing
outwards, and the nenki (date) facing inwards.
The swordsmith’s work is completed. However, the sword is not yet finished. Up to thispoint we have a weapon that will not break, will not bend, and cuts well; but does nothave the soul of the samurai yet.
I spoke earlier of the Shinto ceremony seeking purification. The ceremony must be oneof purity and cleanliness as it involves the gods. For the same reason, it must also bebeautiful. Our ancestors thought that because the Japanese sword is the soul of thewarrior, it too had to be beautiful.
Next is the polishing process, but let’s talk about that next time.