A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5945-00-082-1195
NSN 6110-01-603-9546
NSN 5910-00-855-8027
NSN 6240-01-539-0030
NSN 6135-01-214-6441
NSN 6220-01-605-9623
NSN 6220-01-239-0559
NSN 5945-00-260-4333
NSN 5915-00-112-0947
NSN 5835-01-359-2575
NSN 6610-01-098-5723
NSN 5996-00-539-7956