This specification covers an aircraft-quality, low-alloy steel in the form of bars, forgings, flash welded rings, and stock for forging or flash welded rings.

These products have been used typically for parts, 0.50 inch (12.7 mm) and under in nominal section thickness at time of heat treatment, requiring a through-hardened steel capable of developing hardness as high as 50 HRC when properly hardened and for parts of greater thickness but requiring proportionally lower 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; ARP1110 recommends practices to minimize such conditions.