Form

This specification covers a premium aircraft-quality, low-alloy steel in the form of bars, forgings, and forging stock.

Application

These products have been used typically for hotwork tooling or for parts requiring a steel capable of through-hardening to a minimum hardness of 50 HRC in section thicknesses up to 12 inches (305 mm) with relatively high levels of strength, fatigue resistance, ductility, and thermal stability for use in service from -100 to +1000 °F (-73 to 538 °C) and where such parts may require welding, 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. ARP1110 recommends practices to minimize such conditions.