FED-STD-H28/4 (NOTICE-1), FEDERAL STANDARD: SCREW THREAD STANDARDS FOR FEDERAL SERVICES, SECTION 4, CONTROLLED RADIUS ROOT SCREW THREADS, UNJ SYMBOL (
FED-STD-H28/4 (NOTICE-1), FEDERAL STANDARD: SCREW THREAD STANDARDS FOR FEDERAL SERVICES, SECTION 4,
CONTROLLED RADIUS ROOT SCREW THREADS, UNJ SYMBOL (09 FEB 1998).