Manufacturing a knife involves multiple steps that are important to ensure a strong and durable blade. Below, Kaz’s Knife and Kitchenware takes a look at each of these steps in detail, from forge welding through to knife stone sharpening.
The first step involves bonding the jigane (malleable iron) and the blade (carbon steel). The red-hot metal jigane is beaten and fired together with the blade using forge welding.
*Carbon steel is the black part towards the tip
While shaping the forged material with a power hammer that moves up and down, the general shape of the kitchen knife is formed. While being hammered, the jigane and the blade are blended and extended. This work is an important process to ensure the metal can be cut without breaking or bending.
The knife is heated to 750°C - 800°C. It’s then dipped into water and cooled. Tempering increases the hardness of the blade.
The cooled knife is heated again and drops of water are dropped onto it, with the temperature judged by how the water drops run. This is a technique that requires skill and experience. As a result, it produces a blade that’s tough and not easily chipped.
The jet-black knife is sharpened with multiple coarse grinding, buffing, hon-togi, ura-togi and whetstones. Knife stone sharpening is an integral part of the manufacturing process to ensure a fine edge.
A handle is attached to the sharpened knife. Finally, it’s finished by adding a name.