A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6685-00-194-1710
NSN 6220-01-530-2931
NSN 6620-01-037-8468
NSN 6650-01-325-0678
NSN 5905-01-532-9102
NSN 6110-01-625-9709
NSN 6650-01-249-3201
NSN 5985-01-466-4946
NSN 5905-01-198-9085
NSN 5925-00-519-0631
NSN 5996-01-119-6535
NSN 6130-01-157-8094