A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5895-01-431-9365
NSN 6135-01-100-3593
NSN 5985-01-372-3069
NSN 5925-01-165-9913
NSN 5920-01-097-9927
NSN 6145-01-397-8526
NSN 5998-00-925-2169
NSN 6685-01-386-3110
NSN 7035-01-013-0934
NSN 5999-00-754-4123
NSN 5960-00-389-2915
NSN 6685-00-659-7831