Yake-Ire

Yake-Ire

Once a blade has been shaped, it must be tempered which may be edge tempered or differentially tempered using the traditional method of yaki-ire which requires application of a clay, ash, earth and water mixture. Yaki-ire is the process that gives Japanese blades their unique temper line which is known as it’s hamon. The hamon is created in numerous patterns depending upon how the Tsuchi or clay mixture is applied. The blade is coated with the Tsuchi mixture which serves as an insulator during the tempering or heat treatment process. Once the Tsuchi has been applied based on the swordsmiths preferences the blade is then heated, and quenched in water (unlike western smiths, who usually use oil). If everything has been done perfectly, the blade will be ready to be polished. If anything is not quite right, the entire yaki-ire process will have to be repeated. A blade can go through the yaki-ire process at most three times before it must be melted down to begin again. Hamon patterns are usually adopted or developed by specific schools or smiths which are handed down from Sensei to apprentice and are often part of the defining identification of who made what.