Form

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

Application

These products have been used typically for parts, 0.875 inch (22.22 mm) and under in section thickness at time of heat treatment, requiring a through-hardening steel capable of developing hardness as high as 50 HRC when properly hardened and tempered, and also for parts of greater thickness requiring proportionately lower hardness, but usage is not limited to such applications.