A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6110-01-238-9160
NSN 6650-00-932-1144
NSN 5895-00-361-2609
NSN 5975-00-499-5741
NSN 6150-01-232-4762
NSN 5999-01-463-7443
NSN 6110-01-458-7125
NSN 6645-01-522-7447
NSN 2925-01-656-8217
NSN 5996-01-453-2464
NSN 6620-01-105-3264
NSN 5835-01-384-3206