THE JAPANESE SWORD FORGING PROCESS - PART 1
From The Samurai Sword Shop
Through the histroy of the samurai, the forging process used in the creation of authentic Samurai Swords is as much an art form as it is a science. The steps involved have been refined throughout this sword’s history however, even with all the technological advancements, much of the work involved remains very similar to the techniques developed by the original masters of this craft.
From selecting the most suitable raw materials to hand-polishing each Japanese sword, the sword making process is a process that requires substantial knowledge of the real Japanese weapons
history. It also requires knowledge of the available materials and probably most important, the process requires patience. It is, after all, the fine craftsmanship and the attention to detail that make the Japanese sword the remarkable piece that it is.
In order to create authentic Japanese swords of the highest quality, it’s important to begin with high-quality steel. It’s also important not to take any short-cuts. The highest quality Japanese swords are made using Tamahagane or iron sand. Few swords made from this traditional material are made outside of Japan.
FOLDING AND HAMMERING
Forge Folding, which is also known as kitae, is an important step in the sword-making process as it is what helps to remove impurities from the raw metals and helps to evenly distribute the carbon content. Folding also is what creates the subtle grain pattern in the metal which is known as the jihada.
To begin, the smith selects the metal pieces he feels are suitable for the project. High-carbon and low-carbon pieces are usually combined which makes the metal malleable. Combining the carbons is also what helps to ensure that the resulting metal is neither too soft nor too brittle.
Once the pieces have been selected, the smith welds the pieces to create the block about the size of a brick that will form the outside layer of the sword called the kawagane. Next, the block is hammered out and folded onto itself several times. This laborious hammering/folding process will be repeated as necessary, usually 10 to 14 times. The smith determines the number of times the folding/hammering process will be repeated.
The folding and hammering process creates thousands of layers within the block. These layers are where the unique patterns called jihada, an important visual component of the Japanese sword, start to develop each time the block is folded and hammered. The smith can influence the look of this pattern simply by folding the block in different ways, either always in the same direction, or in alternating directions, or by folding crosswise.
When the outer layer is finished it is then wrapped around the sword’s inner layer, called the shingane. The two pieces are then welded together and hammered into a long, thin shape that incorporates a slight curvature. Various other tools including planes and files are used to refine the shape of the blade. The piece is rough polished and at this point, it begins to resemble a sword.