A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5835-01-025-8761
NSN 6105-00-407-6244
NSN 6105-01-547-7612
NSN 6240-00-565-9141
NSN 5990-01-128-3758
NSN 5835-01-044-2628
NSN 6620-01-053-6650
NSN 6135-01-530-9327
NSN 5996-01-280-3860
NSN 5999-01-159-8571
NSN 5998-01-353-7281
NSN 6130-01-359-2701