ALMAR 18 is a high-nickel martensitic steel which is strengthened by precipitation hardening. It has excellent combination of strength and toughness particularly in the presence of notches or cracks. It is recommended for applications such as solid fuel rocket cases and aircraft landing gears. It is supplied in three different compositions to produce yield strengths from 200,000 to 280,000 psi. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on low temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SA-156. Producer or source: Allegheny Ludlum Corporation.