A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5935-01-473-7963
NSN 6685-01-100-1071
NSN 5945-01-180-6063
NSN 5905-01-289-0391
NSN 6135-00-889-1485
NSN 5835-01-085-5487
NSN 6620-00-970-2363
NSN 5835-00-113-6090
NSN 6685-00-913-0533
NSN 6685-00-946-5112
NSN 5935-01-433-4340
NSN 5985-00-842-9269