A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5910-01-086-8557
NSN 5930-01-441-8479
NSN 6610-01-177-5033
NSN 5965-01-189-4805
NSN 5960-01-444-2205
NSN 5985-00-681-3586
NSN 5910-01-075-8640
NSN 5999-00-420-1483
NSN 6110-01-448-4265
NSN 5895-01-487-7032
NSN 7035-01-423-8343
NSN 5965-01-261-6073