A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6105-01-431-8998
NSN 5975-01-222-9457
NSN 5965-01-120-6086
NSN 5910-01-334-1877
NSN 6240-01-368-6248
NSN 5920-00-771-7280
NSN 5985-01-217-5881
NSN 5960-01-389-0629
NSN 7035-01-371-0091
NSN 5999-00-328-1649
NSN 6240-01-386-5952
NSN 5855-01-600-0486