A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5925-00-879-9567
NSN 5920-01-150-0758
NSN 5945-00-798-3412
NSN 2925-01-327-3069
NSN 5915-00-705-1780
NSN 6645-00-392-8728
NSN 6130-00-018-8621
NSN 5925-01-436-9833
NSN 6130-00-406-5728
NSN 5935-00-960-7324
NSN 6240-01-369-6464
NSN 5990-01-258-3848