A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5996-01-043-2105
NSN 5895-00-406-3696
NSN 5920-01-501-8467
NSN 6130-00-019-3032
NSN 5975-01-525-7728
NSN 5930-01-153-2667
NSN 6135-01-252-0315
NSN 6645-01-495-0939
NSN 2925-01-174-6786
NSN 5950-00-161-3044
NSN 5905-01-610-2018
NSN 6685-01-139-7388