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 5960-01-627-6547
NSN 5990-01-421-3325
NSN 7035-01-217-3591
NSN 6130-01-608-7925
NSN 5915-01-196-9620
NSN 6130-01-634-0603
NSN 5960-01-019-0017
NSN 6105-00-104-5306
NSN 5910-00-246-9417
NSN 5950-00-028-0082
NSN 5945-01-415-5835
NSN 6135-01-116-3385