The item is a flight safety critical aircraft part (fscap)
A nut having 6 flat sides and an integral washer which extends beyond the flats or periphery. An integral feature is incorporated for locking on the threads of a mating member.
Classification: Nuts of iron or steel
NSN 6685-00-392-4577
NSN 6145-00-493-4073
NSN 6110-01-495-4216
NSN 5910-01-655-0360
NSN 5910-01-525-4794
NSN 5990-01-486-2556
NSN 5930-00-829-3761
NSN 5910-00-830-9575
NSN 6240-01-284-6482
NSN 5930-00-466-3643
NSN 5945-01-176-6961
NSN 5910-01-618-6018