Bi-Metal Die Microstructure of Bi-Metal Die "The High Function Die" Due to extreme demands on certain tools, it is sometimes necessary for dies to be replaced more frequently than other tooling. This occurs more frequently on "heavy duty" and "high usage" jobs which are punched from material such as thick gauge Mild Steel and Stainless Steel. This inevitably results in higher tooling costs. Amada's Bi-Metal Die is an effective way to help combat these costs. As the name suggests, the Bi-Metal Die consists of two metal properties. The upper layer is manufactured from high speed steel, this ensures a very hard and sharp cutting edge. This upper layer is friction welded to a lower layer consisting of a special alloy steel, making the die very tough and durable. Also, a "mushroom" keyway compliments the strength of the die by reducing the risk of fracture and prevents the die base collecting slugs and scrap which can weaken the die further.