What is the structure of the Japanese samurai sword?

Japanese samurai swords learned from our country’s Tang swords, evolved from Japanese culture, and eventually formed samurai swords with Japanese characteristics. Below is the structure of the Japanese katana I shared. Let’s take a look.

The structure of the Japanese samurai sword The structure of the samurai sword

1. Head: the cover of the head of the handle, the silk rope on the handle is knotted on the head, mostly made of copper and iron. Metal products.

2. Handle roll: The silk rope wrapped around the handle of the knife acts on the center of the fixed surface and makes the handle easier to hold and less likely to fall off.

Third, knife: Most of the decorations on the handle are metal products, with fine workmanship. They are the favorite of collectors in the field of Japanese metal crafts.

Fourth, tan: or e, commonly known as the guard or sword grid in modern times. It has the same function as the hand guard. In addition to protecting the palm, it is also the part that must be used when drawing the knife. It is also the most exquisite accessory for knife decoration. Like the eye guard, it is the focus of a collection that has a unique world in the minds of collectors.

Fifth, millet shape: When the knife is tied to the waist, the scabbard is fixed to prevent it from slipping. Mostly made of wood or angle.

Sixth, lower thread: When the knife and fork are placed at the waist, tie the end of the lower thread to the belt. To prevent the scabbard from slipping, the material is mostly made of silk.

Seventh, Dang: the sheath at the end of the scabbard, mostly made of metal or horn.

8. Shark handle: the mackerel skin wrapped on the handle of the knife, commonly known as shark skin in China. This fish is native to Southeast Asia. The grown fish is about one and a half feet long. The surface of the leather is covered with protruding fine stone particles, making it easy to wrap the handle around the handle of a knife. The shark skin has been expensive since ancient times, but it was loved by warriors. And rush to buy.

9. Hairpin: used for fixing the blade and decoration, and can also be used as hairpin and ear palladium. Most of them are copper or copper alloy products.

10. Return angle: The device that prevents the scabbard from protruding and falling to the ground. It is mostly made of wood. If it is a metal product, it is called "response gold". But not every knife has this accessory.

Expansion:

Japanese samurai sword making method

Japanese swords have a very high level of technology in making them, and they include steel training, knife making, To polishing and sharpening the knives are made by different masters. ***It is divided into the following steps:

Steelmaking

The material steel of Japanese swords is called Wakou (Wakou) or Tamangang (たまはがね, Tamahagane). Jade steel is made using traditional Japanese methods. This is a low-temperature steelmaking method, with the furnace temperature not exceeding 1000°C. This method may seem primitive, but compared to modern high-temperature steelmaking methods, it can produce good steel with pure quality. However, steel produced at high temperatures is softer and easier to shape, while steel produced at low temperatures is harder and more difficult to forge. It can be said that making Japanese swords is a labor-intensive fortification, and quality is obtained with blood and sweat. According to different regions and different schools, the composition of the steel used will be different, and the steel-making master will only visually select the steel that he feels is of the best quality from the smelted steel and send it to be made into a samurai sword. Generally speaking, the ingredients contained in jade steel are as shown in the table.

Water Subtraction

The jade steel sent to the knife maker is not a complete piece of steel; it is fragmented and incomplete; it is scattered into several pieces. The master swordsman must restructure these scattered jade steel into a single piece of steel that can be made into a samurai sword. This process is the quenching process. Quenching is the so-called heat treatment. In Japan, it is called water reduction (みずへし, Mizuheshi). From the perspective of modern material science, this step can be regarded as a knifemaker's method of controlling the carbon content of steel.

First of all, in order to prevent the jade steel from being oxidized by the air, the steel must be covered with clay; then the cutter will hammer the heated and steel into flat sheets with a thickness of about 5mm. It seems like a simple process, but it is not. In order to control the carbon content of the steel, the number of heating times is strictly limited; and the hardness of the steel will change as it continues to cool. Only experienced knife workers can accurately grasp the changes in hammering force and temper the jade steel into thin slices of uniform thickness under a limited number of heatings.

After the steel sheet is formed, the knife will quickly cool it with water. It can peel off excess carbon-containing parts of steel. The blade has good elasticity and the blade is hard and not easy to chip. The knifemaker needs to have an extremely accurate grasp of the temperature of the steel sheet and the amount of water in order to obtain a material with the appropriate carbon content.

Exercise

The knife worker beats the red-hot steel block for forging. The steel block is beaten open and then folded up and beaten. Repeat this until the 10th time, and there will be 1024 layers. Through this step, impurities such as sulfur and excess carbon in the steel can be removed to increase the elasticity and toughness of the steel. This is like kneading dough. The more layers you beat, the more uniform the carbon and various components in the steel will be, and the finer the iron crystals will be. The final forged steel will have uniform quality, thousands of layers, and is very strong. .

Steel Matching

The shape of Japanese swords, whether the tip or the entire blade, is based on a circle. The reason why the blade is curved is mainly caused by the matching and quenching of steel. of. First, the knife is wrapped with Hagane (Hagane) and Hagane (Kawagane), which are hard and high in carbon content, and Shingane (Shingane), which is soft and low in carbon content. In Japanese, it is called Tsukurikomi (つくりこみ). This dual structure is a major feature of Japanese swords. The edge metal and leather iron on the outside make the knife sharp and have the right hardness to prevent it from bending. In the subsequent burning stage, the amount of carbon and the cooling rate of the firing are used to control the difference in volume expansion between the blade tip and other parts, thereby generating strong compressive stress at the blade tip, making the blade less likely to be damaged, and forming a curved edge of the scimitar. radian.

Japanese samurai sword cross-sectional structure diagram

Sunobe

The shape of the sword is beaten and extended into a long bar, called sunobe (すのべ, sunobe). At this stage, the prototype of the knife basically appeared. After this step is completed, the knife will cut off the frontmost part to make the tip.

Burning in

? Quenching? The last fire forging process. The knife maker first prepares Yakibatsuchi (Yakibatsuchi) from clay, charcoal powder and whetstone powder, and then encapsulates the shaped blade with Yakibatsuchi. The soil used for the blade is thinner, while the soil used for the pickaxe and ridge is thicker. Basically, some clues about the distribution of Burning Blade Earth can be seen from the blade text of the finished product. The ingredients and preparation methods of Shao Ren Tu from different schools also vary. The sealed blade will be placed in a furnace fire at 750°C - 760°C (when it reaches the temperature, the blade will appear fiery red like the morning sun). Knife makers judge the temperature in the furnace based on experience based on the color of the flames. If the temperature exceeds 800°C, it will affect the strength of the knife (the blade will crack). After a specific heating time, the knifemaker will put the knife into water to quickly cool it and perform another quenching process. Through this step, the knife becomes harder and sharper, the blade will naturally curve, and a very strong layer of Martensite crystals or Martensite is formed on the surface of the knife. In short, the so-called Maddens crystal (Maden bulk) is a high-temperature crystal structure that due to rapid cooling, the carbon atoms are locked in the crystal grains, resulting in a metastable state, so the crystals are in a metastable state. There is a lot of internal tension, creating a hard effect. After this step, a granular pattern like sprinkled silver sand is produced at the boundary between the blade and the blade surface, which is called boiling (にえ, Nie) in Japanese. Taken as a whole, these tiny white dots form white mist-like lines, called Nioi (におい, Nioi), which are an important basis for appreciating the quality of a Japanese sword.

Because this step requires very high technical requirements, a slight mistake may cause the blade to break and cause fatal damage to the entire knife. In addition, even if it is barely formed, it may not produce beautiful patterns. In order to reduce mistakes, knife makers now mostly use oil to perform the burning step.

Finishing

At this point, the knife has been basically formed and needs to be transferred to more detailed deep processing.

Forging and pressing

Adjust the curvature of the knife after it has been fired and perform rough cutting. At this time, the inspection and trimming of small flaws, the shape of the cutter body, etc. enter the final adjustment stage.

Stem

The part set aside for installing the knife handle is called stem (なかご, Nakago) in Japanese, and it can also be written as center, neutron. The knife maker adjusts the shape of the stem and creates a Mekugiana hole for inlaying the handle. And engraved with Yasurime (やすりめ, Yasurime). This part is prone to rust, and the age of the knife can be roughly determined based on the rust.

Inscription

Generally, the knife maker will engrave his name, residence, and the year and month of production on the stem at the end. Strictly speaking, the inscription is cut or chiselled on the stem with a sharp instrument. Generally, the name of the swordsman and his address are engraved on the outside (the outside side is the outside when wearing the sword), and the year and month of production and the name of the sword holder are engraved on the inside, but there are many exceptions.

After the above steps are completed, the knife maker’s work has come to an end. Processes such as grinding, sheath making, decoration, and handle rolling are handled by dedicated personnel and are not within the scope of the knife maker’s work.

Other accessories

Japanese samurai sword accessories include sheaths, handles, hairpins, rims, heads, heads, tangs, etc.

Among them, Tsuba (つば, Tsuba) is the main accessory. The tsuba is equivalent to a general sword grid or hand guard. Its function is:

The switch for drawing and retracting the sword.

Protect palms and wrists during fighting.

It is a symbol of social status, honor and nobility.

Before the Azuchi Momoyama period, the emphasis was on practicality, that is, the first two items, and later on, the emphasis was on decoration, that is, the third item.