This specification covers an aircraft-quality, low-alloy steel in the form of bars, forgings, mechanical tubing, and forging stock. These products have been used typically for parts requiring a combination of high tensile strength and good ductility with relatively-high impact strength and hardness, but usage is not limited to such applications. Certain design and processing procedures may cause these products to become susceptible to stress-corrosion cracking after heat treatment. SAE ARP 1110 recommends practices to minimize such conditions.