MIL-S-7393C (AMENDMENT 1), MILITARY SPECIFICATION: STEEL ALLOY CARBURIZING, BARS AND BILLETS, STEEL NICKEL-CHROMIUM (3310, 3316 AND 9310), AIRCRAFT QUALITY (22 JUL 2002)., This amendment forms a part of MIL-S-7393C, dated 28 AUGUST 1968, and is approved for use by all Departments and Agencies of the Department of Defense.