A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 4140-01-632-3377
NSN 5910-00-420-3305
NSN 7035-01-633-9537
NSN 5930-00-785-4751
NSN 5925-01-144-0445
NSN 5835-00-986-5985
NSN 5945-01-012-3610
NSN 5999-01-473-4236
NSN 6135-01-077-5705
NSN 6645-00-754-4108
NSN 5950-00-012-2490
NSN 6610-01-364-8295