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 5915-01-204-9482
NSN 6130-01-171-7003
NSN 4140-01-225-9539
NSN 2925-00-167-6763
NSN 6320-01-116-3980
NSN 6150-00-840-3674
NSN 2925-01-439-0219
NSN 5935-01-125-3981
NSN 5975-00-178-1584
NSN 5925-00-387-3956
NSN 6610-01-234-9098
NSN 6105-01-245-8932