MIL-S-7720A, MILITARY SPECIFICATION, STEEL, CORROSION,RESISTANT (18-8) BARS, WIRE AND FORGING STOCK (AIRCRAFT QUALITY) (25 OCT 1967) [S/S BY SAE-AMS-S-7720]., This specification covers the requirements for compositions of corrosion-resistant (18-8) steel bars, rods, wire and forging stock.