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 6620-00-916-3134
NSN 5935-01-415-0887
NSN 5915-01-215-1473
NSN 5998-00-205-2951
NSN 6220-01-359-4857
NSN 5960-00-005-7132
NSN 7035-00-124-9383
NSN 5920-00-581-9471
NSN 6220-01-415-0553
NSN 2925-01-456-6010
NSN 6645-01-528-7152
NSN 5895-01-379-6248