Alloyed Japanese carbon steel , martensitic, due to carbide formation somewhat tougher and more wear-resistant than White Paper Steel , coarser grain. With heat treatment instructions. (C = 1.1 - 1.2%, Si = 0.1 - 0.2%, Mn = 0.2 - 0.3%, Cr = 0.2 - 0.5%, W = 1.0 - 1.5%, P <0.025%, S <0.004%)