A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5920-00-407-0310
NSN 5930-01-172-7541
NSN 5975-01-545-4309
NSN 5975-01-008-9099
NSN 5915-01-157-0977
NSN 5950-00-395-9976
NSN 6240-01-171-0374
NSN 5920-01-556-4823
NSN 5999-01-081-7300
NSN 5910-01-429-4648
NSN 6105-00-130-6961
NSN 5960-01-034-6537