A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5895-01-260-4206
NSN 5996-01-421-4080
NSN 5855-01-180-5369
NSN 6135-01-167-7604
NSN 5985-01-272-9745
NSN 6105-01-504-8764
NSN 6110-01-633-9660
NSN 6645-01-412-5781
NSN 5990-00-803-0490
NSN 5960-01-138-3337
NSN 5975-00-890-9860
NSN 5910-00-473-5755