A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6645-00-067-7070
NSN 5999-00-160-5366
NSN 6145-01-130-9585
NSN 5996-00-960-9494
NSN 5915-01-442-3822
NSN 5910-00-202-1056
NSN 5965-01-444-3098
NSN 6645-01-370-4259
NSN 5855-01-110-9564
NSN 5835-01-644-8013
NSN 6320-01-449-1014
NSN 6150-00-196-0696