Volume 16 of the Tang Dynasty's Six Classics records that there are four types of swords, one is the ritual knife, two is the barrier knife, three is the horizontal knife, and four is the Mo knife.

The word "Tang Knife" is a general term for the four saber styles of the Tang Dynasty. It does not specifically refer to a certain kind of knife. It is commonly known as "Tang Knife". Its narrow and straight blade body, small cube, and long handle (can be held with both hands); the direct prototype is the collection of Masakura Inn in Japan, and the "Gold and Silver Ding Tang Dao" imported from the Tang Dynasty. The sword shape of the Tang sword originated from the Han Dynasty's ring-headed sword. Most military Tang swords retained the ring-headed sword in the early stage, and also had a straight blade.

The Tang sword is an army combat knife. Its biggest function is to fight. Its production process is strict and another purpose must be taken into account when fighting, which is armor-breaking and durability. Armor-breaking requires hardness, and a narrow edge, while durability requires toughness. Therefore, the Tang sword adopts the most advanced steel-blocking process. It uses cooked iron as the outer skin and has hundreds of steel-making in the middle. Some of the blades adopt local quenching technology, namely, covering the soil and burning the blade. The hard edge can chop and break the armor, and the blade body is tough and does not deform and durable. This is also the biggest difference from Japanese swords.

The full name of Japanese knives is a flat-broken dark-light patterned blade. According to their shape and size, they can be divided into Taidao, Knife, Rib Difference (Rip Finger), Short Knives, etc. The material steel of Japanese knives is called Hesteel or Jade Steel. This is a low-temperature steelmaking method with a furnace temperature not exceeding 1000c. This method seems primitive, but compared with modern high-temperature steelmaking methods, it can produce pure quality steel. The steel made from high-temperature steel is softer and easy to build. The steel made from low-temperature steel is harder and more difficult to build. It can be said that making Japanese knives is a human-intensive fortification, which is a quality exchanged for the blood and sweat of thousands of times.

Its main production process is divided into: pill forging - that is, the knife means that the steel material is heated until red and beaten and forged. After the steel block is opened, it is folded and beaten. This repeatedly makes the steel material extend. Usually, it can be beaten at least 7 or 8 times, and at most 20 or 30 times, and each time it has to be beaten hundreds of hammers. For example, when the hammer is hit the 10th time, there will be 1,024 layers of steel. Through this step, impurities such as sulfur and excess carbon in the steel can be removed, so as to

Increase the elasticity and toughness of steel. This is like kneading dough. The more layers of pounding, the more uniform carbon and various components in the steel will be, and the iron crystals will be more detailed. The final forged steel is of uniform quality, reaching thousands of layers, which is very strong, and eventually becomes a steel with a uniform texture. The unique patterns on Japanese knives are hammered in this way. There are many methods of hammering forging, such as cross forging, folded wood forging, short book forging, wood forging, wood forging, etc., with different patterns.

Water reduction - that is, quenching process, quenching is the so-called heat treatment. After the hammered steel sheet is formed, the knife worker will use water to quickly cool it. The excess carbon-containing part of the steel can be peeled off. The blade body has good elasticity and the blade edge is hard and not easy to get a gap. The knife maker must have an extremely accurate grasp of the temperature of the steel sheet and the amount of water used to obtain a material with a suitable carbon content.

Steel matching: The shape of a Japanese knife, whether the tip or the entire blade is based on "circle", is mainly caused by the combination of steel and quenching. First, the knife is wrapped with a hard and hard blade with a small carbon content and a soft texture. It is called crafting in Japanese. The outer blade and skin make the blade sharp and appropriate hardness not bend. In the subsequent burning stage, the difference in volume expansion between the blade tip and other parts is controlled by the amount of carbon and the cooling speed of the inlet, so that the blade tip produces strong compression stress, making the knife less likely to break and form the arc of the scimitar.

Su Yan: The shape of the knife is beaten and extended into a long strip, called Su Yan. At this stage, the prototype of the knife basically appears. After this step is completed, the knife workers will cut off the front part to make the tip of the knife.

Burning blade: The knife first uses clay, charcoal powder and whetstone powder to make the burning blade soil, and then the formed blade body is wrapped with burning blade soil. The blade is thinner and the pick and floor soil is thicker. The sealed blade body will be placed in the furnace fire of 750c-760c. The knife method judges the temperature in the furnace based on experience based on the color of the flame. If the temperature exceeds 800c, it will affect the strength of the knife. After a specific heating time, the knife will put the knife in water and cool it quickly and perform another quenching process. Through this step, the knife becomes harder and sharper, and the heat rises and shrinks, causing the blade to bend and creates a curve, and a very strong "Madens crystal" or "Matian Powder" on the surface of the knife

". The so-called Madens crystal (Mata Pellet) is simply that the high-temperature crystal structure is locked in the grains due to quenching, resulting in a "metastable" state, so there is a great internal tension between the crystals, resulting in a "hard" effect. After this step, granular patterns like sprinkled silver sand are produced at the boundary between the blade and the knife surface, which is called boiling in Japanese. Overall, these small white dots form white mist-like lines, called thorns, which are an important basis for appreciating the quality of a Japanese knife. Due to this step, the technical requirements are very high, and if there is a slight mistake, it may cause the blade to collapse and cause fatal damage to the entire knife. In addition, even if it is barely formed, beautiful patterns may not be produced.

At this point, a Japanese knife has taken shape and is basically the final work later.

Forging: Adjust the bending degree of the knife that has been inserted, and the tooling is roughly cut.

Stem: The part left for installing the knife handle, which is called the stem in Japanese, can also be written as a center and a neutron. The knife worker adjusts the shape of the stem, opens a staple used when inlaying the handle, and carves the zigzag.

Mingke: Generally, knife workers engrave their names, residences, and production years on the stems at the end. Strictly speaking, the inscription is "cut" or "engraved" on the stem by sharp tools. Similar to the Qin Dynasty, the workers in pottery workshops implemented the system of "the name of things is to test their sincerity" for the workers, requiring craftsmen to print or carry their own names on the body of the made figurines. This was written by the ruler to inspect the quantity and quality of pottery figurines made by pottery workers, but it left a large number of names of artists for future generations. Nowadays, those who can distinguish them include "gong Bing", "gong Jiang", "gong Bai", "Xianyang Wu", "Liyang Chong", "Lin Jin", etc.

There are also grinding, sheathing, decoration, and rolling handles behind them. At this point, a Japanese knife is truly completed.

The knife assembly of Japanese knives also includes sheath, small handle, hairpin, edge, head, eyebrow, snail, etc.

Among them, squid is the main accessories, squid is equivalent to a general sword grid or handguard. Its functions are: switches for making and retracting the knife; protecting the palms and wrists during fighting; showing social status and honor, and symbols of nobility; before the Atsu Momoyama era, it focused on practicality, that is, the first two items, and later on, it focused on decorativeness.
Chapter completed!