The top of the teeth of a blade are required to be hard and the backing to be ductile. These antithetic conditions were cleared by Amada’s bi-metal blades produced by using special electron beam welding. A blade that is composed of two types of material, i.e., the highest grade high speed steel for teeth and tough special spring steel for the backing, exhibits the performance that it is no comparison with conventional quench hardened blades…high speed, high accuracy and long service life. It can handle hard to cut materials of a wide range, it is strong against bending and torsion, and it makes possible large reductions in the cutting cost.