A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5915-01-062-0592
NSN 6610-01-479-0466
NSN 5930-01-631-3871
NSN 4140-01-438-0310
NSN 6685-01-112-5746
NSN 6110-00-066-9614
NSN 5950-01-655-1836
NSN 6685-01-498-4631
NSN 5960-01-353-5947
NSN 6220-01-555-8332
NSN 5920-00-608-9731
NSN 7035-01-472-8658