San Mai
November 18
A traditional Japanese blade construction technique that involves sandwiching a core layer of hard steel between layers of softer steel. The outer layers, known as "jigane," are typically made of softer, more flexible steel, while the inner core, known as "hagane," is made of harder, more resilient steel. This creates a blade with the sharpness and edge retention of the hard steel core, combined with the flexibility and durability of the softer outer layers.