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 5930-01-645-0474
NSN 6105-01-524-3994
NSN 5895-01-513-7386
NSN 6650-01-082-5534
NSN 5925-01-559-5397
NSN 6105-01-354-5874
NSN 5950-01-440-4229
NSN 6620-01-239-7671
NSN 6145-01-249-8540
NSN 6110-01-422-0526
NSN 5996-01-279-0143
NSN 4140-01-347-6503