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 6110-01-178-0814
NSN 5975-00-283-1320
NSN 5915-00-682-0650
NSN 5935-01-327-2759
NSN 5895-00-728-3655
NSN 7035-00-153-3826
NSN 5905-01-099-9496
NSN 6150-01-188-8232
NSN 5999-00-215-7295
NSN 2925-00-159-9003
NSN 2925-00-150-7334
NSN 5935-00-244-6065