SAE AMS 6424F

This specification covers an aircraft-quality, low-alloy steel in the form of bars, forgings, mechanical tubing, and forging stock.These products have been used primarily for parts 3.5 in. (90 mm) and under in nominal section-thickness at time of heat treatment requiring a through-hardening steel capable of developing hardness as high as 40 HRC and also parts with thicker cross-section which require proportionately lower hardness, but usage is not limited to such applications.

This product replaces:SAE AMS 6424E - Steel Bars, Forgings, and Tubing 0.80Cr 1.8Ni 0.25Mo (0.49-0.55C)