Bainite is a structure of high-carbon steel that combines great strength with excellent flexibility and shock absorption characteristics. It has been known as an exemplary Katana blade component for a number of years but its use has been restricted to a few top-class master smiths, due to the difficulties involved in performing the exacting heat treatment procedures necessary for the production of a Bainite blade body in combination with the very hard Martensite Yakiba (edge section) required for Katana blades.