A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5990-01-143-2518
NSN 5945-01-009-8880
NSN 6130-01-072-3137
NSN 5915-01-265-0326
NSN 5835-00-280-8494
NSN 5960-00-011-9315
NSN 5990-01-548-5979
NSN 5990-01-390-2177
NSN 6135-01-167-7604
NSN 6685-00-842-6721
NSN 7035-01-617-0072
NSN 5835-01-362-1946