THERMOLD J is the basic 5% chromium hot-work steel, modified by the addition of 1.5% nickel and higher carbon content. The nickel addition is intended to increase the toughness to compensate for the higher carbon. The exceptional properties of Thermold J have led to wide usage in both hot and cold-work applications. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, and machining. Filing Code: TS-330. Producer or source: Cyclops Corporation.