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 5920-00-781-3572
NSN 5905-01-062-3332
NSN 5945-00-080-7136
NSN 5996-00-212-5917
NSN 5895-00-953-4916
NSN 5920-00-856-9663
NSN 5935-01-173-0359
NSN 5915-01-058-5449
NSN 5905-01-204-4553
NSN 5930-00-690-1152
NSN 5895-01-569-7446
NSN 6145-00-112-1449