A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5975-01-206-6316
NSN 6650-01-354-3363
NSN 5965-01-222-2613
NSN 6110-01-435-9906
NSN 6620-01-598-2271
NSN 5985-01-423-9769
NSN 5998-00-769-9477
NSN 5895-01-241-9924
NSN 6135-01-501-5376
NSN 5905-00-754-3327
NSN 5895-00-170-4568
NSN 6620-01-133-4193