A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6110-00-481-7022
NSN 5965-00-011-6742
NSN 6320-01-317-7312
NSN 5920-01-477-7221
NSN 2925-01-545-2717
NSN 5855-01-400-1590
NSN 5999-01-519-2998
NSN 5945-01-253-8424
NSN 5945-01-519-2733
NSN 6150-01-322-8112
NSN 5905-01-401-5325
NSN 6645-01-271-7583