The knife blade is heated to a temperature exceeding 800°C (an example of traditional carbon steel) and then quenched.

After this "quenching" process, the blade undergoes a process called "tempering," in which it is heated at an appropriately high temperature for a certain period of time, resulting in a blade that is appropriately soft and has just the right strength (toughness).

The required heat treatment conditions vary depending on the type and shape of steel. In order to maximize the potential of each steel material, we are constantly adjusting each heat treatment process to achieve the best results based on accumulated data.