A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5895-01-108-7895
NSN 2925-01-478-8191
NSN 5935-00-578-5687
NSN 6240-01-529-6624
NSN 5835-00-675-5159
NSN 5999-00-608-4260
NSN 5945-01-068-9973
NSN 6645-00-498-6869
NSN 5960-00-273-3058
NSN 6150-01-197-9063
NSN 5905-01-510-2312
NSN 5930-01-357-6511