A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5920-00-705-2916
NSN 5990-01-164-8673
NSN 5835-01-190-0482
NSN 5905-01-648-0228
NSN 5935-01-119-0873
NSN 6650-00-312-1200
NSN 5985-01-131-8275
NSN 5855-01-459-9254
NSN 5990-00-184-5750
NSN 6320-01-084-8821
NSN 6110-01-437-1495
NSN 5965-00-188-5531