A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6145-01-286-4720
NSN 4140-00-924-8116
NSN 6320-01-227-2648
NSN 6610-01-396-5344
NSN 5985-01-015-2405
NSN 5996-00-862-5514
NSN 5855-00-100-9003
NSN 5985-01-605-0230
NSN 6685-01-551-8504
NSN 6645-01-038-2829
NSN 6150-01-257-5798
NSN 5999-01-209-2166