Mysterious weapon--Swords

Since human found the first kind of metal, copper, the development of blades making have become prosperous. Edged weapon is one of the most frequently used equipment for battles and wars in the human history. Ancient people believed that a finely made sword has spirit, making the weapon more powerful and magical. They also believed that humans' soul can be contained in the blades, giving swords consciousness to choose their own masters. Although people mostly use guns as weapons for battle, the attractiveness of swords still exist. High quality and delicate blades or antique swords are precious to collectors. They are willing to pay millions of dollars to get such a treasure.

Nowadays, the blade making industry is still common. Blade smiths are dedicating to making knives as pieces of arts or practical weapons such as hunting knife.  To make a high quality blade, blade smiths must go through many processes carefully. The first step of making blades is initial forging. Initial forging is a process in which blades are shaped. To give blades an approximate shape, smiths have to put the material in the forge, increasing the temperature of metal. When the temperature of metal gets very high, the material can be shaped easier with a hammer. If the material is shaped before reaching the temperature that is high enough, the metal will not be shaped easily and may have some cracks after being hammered.

The second step of making blades is grinding. Through this process, blades will have more accurate and detailed shape. Blade makers normally use machines such as grinding wheels and belt sanders to create the sharp edges and give specific functions to the blades. By using different methods of grinding, blade smiths can emphasize particular functions such as thrusting and chopping.

After giving shapes to blades, the next step will be to harden them. Materials are stronger when the atoms with in them are aligned in the same direction. That is to say, the structure of atoms decide the strength of the material. Since blades are made in alloy or carbon steel, the arrangements of atoms are not consistent. Therefore, the blade are usually not hard and tough enough. To make blades more durable, an important process must be done- the heat treatment. During the heat treatment, blades will be heated to a high temperature and then cooled instantly in water or oil. When being heated, the boundary of different material in metal disappears, making the structure of material more consistent and increase the hardness of steel. However, if material is over heated, steel will crack while cooling because of the instant change of material size.

The final step of making blades is blade finishes. There are many types of finishes. Each of them can achieve different purposes such as making the surface of blades prettier or giving blades better resistance to corrosion. This process has a great influence on the quality of blades.

Swords can be made out of many materials. The most common materials are carbon steel, stainless steel, too steel, and alloy steel. Each of them has different degrees of  hardness and toughness. The choice of material depends on what portrait of blades do makers want to emphasize. They always consider the balance of hardness and toughness before they choose the material for blades because the harder the material is, the more brittle the material will be.

Speaking to the materials and the techniques. There's one way to make a hard and beautiful swords---using Damascus steel. Damascus steel is a kind of high-carbon steel. It can be used to make sharp and strong blades. The most spectacular portrait of Damascus steel is that it creates distinctive pattern of banding and mottling on the surface of swords. However, the material of Damascus steel swords and the technique to deal with them were lost. The present blades smiths are trying to duplicate and recreate those techniques. The modern Damascus steel are created by welding many layers of steel sheets together. The modern Damascus steel can also give high toughness to swords and create distinctive patterns on their surface. Nevertheless, the real material and technique of making Damascus steel is still a mystery.