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

Application:

Primarily for critical bearing components requiring a through-hardening steel, usually with hardness of approximately 60 HRC and section thicknesses of 0.40 to 0.80 inch (10.2 to 20.3 mm), and subject to very rigid inspection standards.