Quenching is a critical step in the sword-making process that involves rapidly cooling a heated blade to alter its internal structure. In simpler terms, “to quench” means to immerse or cool hot metal—usually steel—in a chosen medium, such as oil, water, or brine. The goal of this technique is to increase the hardness and strength of the blade while also promoting a certain level of toughness.
When a swordsmith heats steel until it becomes red-hot and then plunges it into a quenching medium, the rapid drop in temperature causes changes in the metal’s crystalline structure. This transformation locks in the properties needed for a sword that can both hold a sharp edge and withstand impact.
