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 6220-01-044-0708
NSN 6130-00-230-3746
NSN 5975-01-127-5988
NSN 5910-01-556-0538
NSN 5965-01-213-3989
NSN 5855-00-294-7532
NSN 4140-00-482-2668
NSN 5996-01-261-6758
NSN 5935-01-512-1697
NSN 5935-01-167-5139
NSN 5925-00-513-7610
NSN 6240-01-394-8125