AISI Type S2 is a water-hardening tool steel with extreme toughness and resistance to shock loading. Even at a hardness of Rockwell C 59-60, it will bend before it breaks. When hardened in medium-size and large-size pieces, it acquires a hard case and a tough core. Sizes under 3/4-inch (19mm) diameter will water harden to the center. The extreme toughness of Type S2 makes it suitable for use in many applications where no other tool steel will hold up. Its many uses include chisels, rivet busters, spike mauls, screw drivers, punches and sledges. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-408. Producer or source: Tool steel mills.