A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 7035-01-125-3329
NSN 6145-01-005-1374
NSN 6110-00-686-0581
NSN 5855-01-201-4857
NSN 5855-01-400-1590
NSN 5960-01-468-6508
NSN 5990-01-253-7647
NSN 7035-01-220-6392
NSN 6150-01-464-3456
NSN 5996-01-025-2333
NSN 6150-01-363-2798
NSN 6610-01-342-5952