The Chemistry Side of Forging a Sword

The Chemistry Side of Forging a Sword

The forging of a sword is deeply centered in chemistry. Swords have been an important part of our history as humans, playing a huge role especially during Medieval and Renaissance times in Europe. The strength of a sword was a deciding factor to a Medieval army's success; a brittle sword would be a man's death sentence. The sword is also a way of showing the owner's wealth by the adornment it carried. However, a good sword begins with the proper materials.

Alloys of metals must be carefully chosen as to not weaken the weapon. A plain carbon steel is ideal (for example, AISI/American 1050/10xx) because of its high carbon content, which makes a harder steel for the sword because carbon contributes to a rigid crystalline structure. Another important component of the steel is a sizeable amount of silicon, because it is an impurity in an alloy and doesn't form solid crystals which provides the sword with flexibility and strength. Obviously, a large and important part of the content of the steel is iron, and a manganese content is recommended for its deoxidizing properties. Those main elements are commonly recommended elements for forging a sword to make the weapon strong and not brittle.

Proper heating and cooling patterns are essential in ensuring that the sword does not become brittle. The steel must be heated evenly (known as white heat) but not so hot that it turns to liquid and begins to evaporate. The white hot metal is placed on an anvil and is hammered and shaped, thinned from its center to each edge, which forms a diamond-shaped cross section. At the beginning and end of joining and shaping the metal, the blade should be coated in borax, called fluxing the metal, which fills any spaces when it melts preventing oxygen from becoming trapped inside and weakening the weld. A strong sword not only relies on the chemical properties of the sword, like the elements it consists of, but also its physical properties.

The physical shape of the sword must be altered and the hilt should be designed and even adorned. The sword handle can be designed by engraving, etching with acid, or inlaid with precious or semi-precious stones for decoration and adornment.