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 5855-01-410-8979
NSN 6110-00-613-1430
NSN 5925-00-959-4983
NSN 5985-01-327-3451
NSN 5965-01-364-7275
NSN 5965-00-553-3505
NSN 6110-00-623-3468
NSN 6650-01-219-3731
NSN 5998-01-526-8298
NSN 5905-00-393-2757
NSN 5855-01-342-3824
NSN 5905-01-102-5223