A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5915-00-885-8579
NSN 5905-00-176-2695
NSN 6110-01-257-1145
NSN 5990-00-873-3079
NSN 6135-00-161-0746
NSN 5975-01-335-6810
NSN 2925-00-400-2760
NSN 5905-00-102-9612
NSN 5895-01-583-7411
NSN 6220-01-457-2318
NSN 6645-01-659-8683
NSN 5960-00-145-5378