JALLOY 7 is a manganese-molybdenum oil-hardening steel applicable where high hardness with good ductility or wear resistance is desirable. This datasheet provides information on composition, hardness, and tensile properties as well as fracture toughness. It also includes information on heat treating, machining, and joining. Filing Code: SA-32. Producer or source: Jones & Laughlin Steel Corporation. Originally published August 1955, revised January 1963.