11Ni-13Co Maraging Steel (var. 6)

11Ni-13Co Maraging Steel (var. 6) is a precipitation-hardening iron-nickel-cobalt alloy designed to achieve very high strength levels through controlled aging rather than carbon hardening, resulting in a martensitic structure with exceptional toughness and minimal distortion during heat treatment. This variant is employed in aerospace and defense applications where extreme strength-to-weight ratios, dimensional stability, and damage tolerance are critical—such as landing gear, rocket motor casings, and precision tooling—and is preferred over conventional high-carbon steels when engineers need high hardness without sacrificing fracture toughness or machinability in the solution-annealed condition.