This specification covers an aircraft-quality, low-alloy steel in the form of heat-treated bars 1.50 inches (38.1 mm) and less in diameter or least distance between parallel sides.
This specification covers steel cleanliness requirements in SI (metric) units for aircraft-quality ferromagnetic steels, other than hardenable corrosion-resistant steels, by magnetic particle inspection methods.
This specification covers manganese-silicon-nickel alloy steel bars and forging stock of aircraft quality and suitable for heat treatment to 220,000 psi minimum tensile strength.