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 parts requiring through hardening to a minimum hardness of 50 HRC in section thicknesses up to 12 inches (305 mm) with a combination of high strength, fatigue resistance, ductility, and thermal stability for operation in the range of -100 to +1000 °F (-73 to +538 °C), 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.