A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5990-01-298-3152
NSN 6650-01-074-8232
NSN 5925-00-717-6319
NSN 6130-00-143-7304
NSN 5999-01-351-9236
NSN 5965-01-487-4479
NSN 6145-01-498-4726
NSN 5965-01-118-1416
NSN 5895-01-245-9240
NSN 5835-00-939-7470
NSN 6135-00-269-5843
NSN 2925-00-225-5386