A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5996-00-125-4570
NSN 5965-01-165-9787
NSN 5835-01-416-6449
NSN 6150-01-519-3942
NSN 4140-01-287-3903
NSN 5965-01-231-9125
NSN 7035-01-010-4257
NSN 5999-01-500-4008
NSN 5915-01-510-3867
NSN 5930-01-567-8491
NSN 5910-00-203-2119
NSN 5895-01-435-5090