A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5950-01-456-7300
NSN 6620-01-385-6172
NSN 5975-00-012-3894
NSN 5905-00-832-5237
NSN 6645-00-853-0073
NSN 5999-01-333-0930
NSN 6240-01-656-4920
NSN 6320-00-284-1524
NSN 5990-01-493-4039
NSN 5985-00-223-6202
NSN 5999-01-066-6426
NSN 6135-01-305-6958