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 6110-01-392-3226
NSN 6110-01-641-5006
NSN 6320-01-388-3125
NSN 5965-01-503-8485
NSN 5910-01-564-9064
NSN 5998-01-416-1948
NSN 5855-01-565-0336
NSN 6645-01-243-3138
NSN 6135-00-078-9931
NSN 2925-01-416-6927
NSN 5915-01-444-2860
NSN 5905-01-058-2241