The Chinese Sword
Medieval China saw great advancements in the science of metallurgy. They were far ahead of the technology available in Europe. These advancements allowed China to become a major military power. The power of the sword and arrived.
The basic techniques of forging and tempering developed in China. From these techniques, the renowned Japanese samurai swords were crafted. These skills arrived in Japan as early as the Sui and Tang Dynasty China AD 589.
Research has shown that the sword smiths of China were able to combine the following attributes over the past 20 centuries: Hard and durable edge, a resilient body that absorbs shock without breaking. In a sword this is very difficult to achieve and found to be impossible to combine for centuries before.
Smiths were able to combine these two apparently incompatible attributes by combining hard and soft steels in various ways. Hard steel tends to be brittle but strong. Soft steel tends to be resilient and springy but not strong and easily bendable.
There are 3 basic methods: There is Baogang or wrapped steel method. The hard high carbon steel forms the cutting edge and encloses a softer core of mild steel. The core metal is often folded on itself to increase density and strength. A baogang blade must be made with fairly thick jacket of hard steel or else it will lose it's sharpness after some use.
A more common form of blade forging is qiangang, or "inserted" steel. The high-carbon edge forms a core with is sandwiched between "cheeks" of mild steel. The cheeks are often made of alternating layers of iron and steel, which produce a pattern on the surface when the blade is polished. A skilled smith can manipulate the layers to produce patterns of great beauty, in addition to providing structural strength to the sword.
The last major type of forging is known in the West as "twistcore". This type is formed of parallel bars of twisted layers of hard and soft steel, all welded into a single unit under heat and hammer. When ground and polished, the surface resembles rows of feathery, star-shaped, or swirling elements.
Other technological advancements involved hardening the blade through the use of heat and quenching in liquid. This technique is universal today wherever blades are manufactured. China was one of the few places in which techniques were devised to differentially heat treat the edge as opposed to the entire blade. This technique was then further perfected by the Japanese, who used the skill labor of enslaved Chinese and Korean Smiths.
Editor:Yang Jie
