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 2925-00-132-1280
NSN 6620-01-525-8648
NSN 5985-01-126-5559
NSN 6645-01-468-4990
NSN 2925-00-265-7539
NSN 5915-01-534-9770
NSN 5925-00-920-7066
NSN 5950-01-496-4706
NSN 7035-01-331-5614
NSN 6610-01-511-9079
NSN 5985-01-089-8621
NSN 5835-00-133-9186