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

These products have been used typically for parts 3.5 inches (89 mm) and under in nominal cross-sectional thickness, requiring a through-hardening steel capable of developing a minimum hardness of 52 HRC, the parts being subject to rigid magnetic particle inspection standards, but usage is not limited to such applications. Except for carbon content and tensile properties thsi material sis similar to AMS 6419.

Certain design and processing procedures may cause these products to become susceptible to stress-corrosion cracking after heat treatment; ARP 1110 recommends practices to minimize such conditions.