CARPENTER NIMARK 300 is a vacuum-melted, low-carbon nickel-cobalt-molybdenum maraging steel that develops yield strengths in excess of 270,000 psi (1862 MPa) by simple low-temperature aging at 900 F (482 C) following a solution anneal. It is readily weldable and exhibits good ductility at high strength levels and excellent notch ductility. Its many uses include aircraft structural assemblies, pressure vessels, shafting, bolts and fasteners, and rocket motor cases. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and fatigue. It also includes information on low and high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: SA-423. Producer or source: Carpenter.