The curved single-edge blade of the Japanese katana is one of the world’s most recognizable swords. It originating during Japan’s Kamakura period (1185 to 1333), using high-carbon steel. Today, the katana remains as popular sword among collectors and martial arts practitioners as always.
Many katanas were stolen from the dead during the Second World War and smuggled to countries far from the fallen. The katana is not considered just an object but has a life of its own and is known to be both a teacher and a relative of the family. Under the fittings of the hilt, when one such as this is claimed, found or sold, can be several blacksmith marks in kanji. While many blades were mass produced towards the end of that errible war, many pre-dated those events. If the kanji stamped into the tang is that of the relatives of the dead soldier it is honourable to make contact with your closest Japanese embassy and prepare to return the katana to its original home. I have known of one man who found such a sword while renovating a house, in Castlemaine, Australia, up in the crawlspace beneath teh slant of the corrogated iron roof. He fulfilled the above and was received, all expenses paid and with great fanfare, for honouring the weapon in this way.
PARTS OF THE JAPANESE SWORD
NAGASA
The NAGASA of the KATANA refers to the length of the blade. It is found by measuring in a straight line from the notch at the back of the HABAKI, called MUNEMACHI, to the tip of the blade.
SORI
The SORI measures the curvature of the blade. This curvature can vary according to the katana and has several names depending on the intensity of the curvature.
SHINOGI and SHINOGI-JI
These two Japanese terms are complementary. The SHONOGI is the part from the edge of the blade to the line that determines the flat of the blade. The flat section of the blade is therefore called SHINOGI-JI.
HAMON, BOSHI and YOKOTE
The HAMON is the line of tempering that demarcates the most rigid and sharp part of the blade with the other, more flexible part. We coat part of the blade with a clay mixture that we will heat and temper, the part with the clay will cool much faster and will be more rigid and sharp.
BOSHI
This part refers to the hardening line of the HAMON which extends to the tip (KISSAKI). The polishing of this point can take a long time, as it is very important. It is as important as the rest of the blade and reveals the BOSHI.
YOKOTE
The YOKOTE defines what separates the blade from the KISSAKI. Almost all KATANAS have this feature, there are some exceptions with swords without YOKOTE where the blade is continuous along the whole length.
KISSAKI
The KISSAKI is the tip of the sword. This tip separates the rest of the KATANA blade from the YOKOTE.
HA
The HA is the cutting edge of the blade. It is this part that is usually hardened with the HAMON in the traditional way. The sharpening of this part as well as the hardening and the steels used will determine the quality of the edge, but also its rigidity and solidity. It is important to have a blade that lasts over time and can withstand many cuts.
BOHI and NAKAGO
The BO-HI is a line carved inside the blade of the KATANA that allows to reduce the weight of the blade, but also to adjust the balance point of the sword. This bo-hi throat is also useful for the sound, because it allows to know if the cut is good at the sound of the wind, which is rather satisfactory.
NAKAGO
The NAKAGO is the tang beneath all fittings. It is the part that continues from the blade under the handle. This hidden part reveals many things like the signature of the smith and perhaps the family kanji. Even if this part is not visible at first sight it is actually very important for the strength so that the steel does not break during a cut.
SAYA (SCABBARD)
The SAYA is the scabbard. This SAYA is designed to draw the blade as quickly as possible. Its size is also specific for holding the KATANA without it falling out. This SAYA is usually made of lacquered wood with various patterns and colours.
SHITADOME, KURIGATA and SAGEO
These two parts are a pair. This small part allows to tie the SAGEO which will be then hung on the belt/obi. This brings a practical side as well as aesthetics to the SAYA.
The SAGEO is the cord that allows the KATANA to be attached to the belt (obi). There are different materials for this string and many colours. Traditionally, the colour of the SAGEO is matched to the TSUKA.
HABAKI and SEPPA
Before tackling the handle part, there are some important details between the blade and the beginning of it, which is the Habaki and the SEPPA. These two small parts are linked and very important.
The HABAKI allows maintaining the blade, to fit perfectly in the SAYA to maintain it without it being too complicated to draw the sword, but it also allows reducing the shocks and vibrations felt in the handle during a cut or thrust.
The SEPPA are two small washers to fill the gaps between the TSUBA and the TSUKA, as well as the HABAKI and the TSUBA. This holds the nomenclature better and also reduces shock.
TSUBA
The TSUBA is the guard of the KATANA. It allows both to protect the hand, but also to prevent the hand of the warrior from sliding forward. It also allows for weight and balance point adjustment while being a real work of art.
FUCHI and TSUKA-ITO
The FUCHI is a metal talisman that reinforces the structure of the sword, but also disguises the same beneath. It is often carved in unique traditional patterns.
The TSUKA ITO is the flat cord used to wind the handle (same). There are different techniques and materials for this. The TSUKA ITO can be made of leather, cotton, suede or other materials.
MEKUGI and SAME
The SAME is the stingray leather. Stingray skin or shark skin, this material allows the Ito to hold well on the stingray, but is also perfect to absorb the blows while offering an aesthetic side.
MEKUGIS are wooden pegs (two). These Mekugis help to fix the handle to the blade by passing through the tang. But in reality the handle is already very strong without them and there could be only one MEKUGI.
MENUKI
These are ornaments made of different materials like copper or brass. They are used to facilitate the grip, but also to decorate the TSUKA with the FUCHI.
KASHIRA
The KASHIRA is the pommel of the KATANA, it is made with the FUCHI (similar patterns are often found between the two) and it allows fixing the TSUKA while offering a unique visual.
Blade
- Mune: This is the back edge of the blade
- Ji: The softest section of metal in the back of the blade
- Ha: The harder section of the metal at the front of the blade
- Kissaki: This is the slightly rounded tip of the blade
- Shinogi: The ridgeline of the blade (not the same as the hamon line).
In the past swordsmiths produced the blade using tamahagane steel with differential heat treatment. By coating the spine in a thick layer of clay, swordsmiths could cool it more slowly than the edge, thus resulting in a strong edge and flexible spine.
Habaki
The blade collar found in the katana is known as the habaki. Once the swordsmith created the blade, he would mount the habaki to it at the bottom. Like a hand guard, the habaki was primarily designed to protect the samurai warrior’s hands from self-injury. If a warrior accidentally grabbed the bottom part of the katana’s blade, he would touch the habaki instead of the blade itself.
Tsuka
The tsuka is the handle of part of the katana. It is often designed with intricate carvings and included the swordsmith’s signature.
Parts include:
- Mekugi: These are wooden pegs that adhere the tang of the blade to the hilt.
- Ito: This is a silk wrap that covers the samé for better grip of the hilt.
- Samé: This is the material that covers the hilt of the sword. It’s traditionally ray skin.
- Menuki: A final, decorative charm that is wrapped into the ito. It covers the mekugi.
Saya
The saya is the scabbard in which the katana is stored. While it may sound insignificant compared to the blade, the saya played an important role in preserving the katana and protecting it from damage. Traditionally, lacquered wood was used to make saya, though other materials have since been introduced to the craft.
Sageo
Attached to the saya is a piece of cord known as a sageo. Using the sageo, the warrior can easily carry the katana without necessarily securing it to their uniform.
Tsuba
The traditional Japanese katana also features a tsuba, which is the hand-guard. Normally, the tsuba is either circular or square. Although it does have some aesthetic value, it’s used primarily to protect the hands from self-injury. It is important, when the katana or iaito is in the obi that the thumb of the appropriate hand restrict the drawing of the sword from the saya. The thumb must, however, be off centre so that the warrior does not cut down the centre of the thumb if the sword is pulled by an enemy.