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 5835-00-851-6470
NSN 5965-01-109-2917
NSN 6320-00-343-1798
NSN 5915-01-210-2709
NSN 6620-01-622-9976
NSN 6105-00-758-4190
NSN 6130-01-146-6971
NSN 5895-01-050-9616
NSN 6320-01-245-5307
NSN 7035-01-118-9461
NSN 5925-01-258-2129
NSN 5905-00-944-3884