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 5925-01-618-9984
NSN 6610-01-529-2337
NSN 6150-00-666-3635
NSN 5985-01-651-4949
NSN 6610-00-248-1559
NSN 5998-01-409-2874
NSN 6650-01-618-2285
NSN 6220-00-125-3805
NSN 6110-01-027-0004
NSN 6220-00-920-8225
NSN 5905-01-381-2552
NSN 5935-00-163-1655