A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5998-01-029-3568
NSN 6145-00-835-1088
NSN 6145-00-959-5897
NSN 5960-01-025-2526
NSN 6130-00-494-8451
NSN 5996-01-564-6557
NSN 6145-00-862-7069
NSN 5990-01-264-9759
NSN 5895-00-100-6970
NSN 7035-01-473-7582
NSN 5999-00-703-2008
NSN 6110-00-338-9015