A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5950-00-761-2459
NSN 6150-00-279-9337
NSN 5985-01-004-1149
NSN 5975-01-514-3500
NSN 6320-00-213-0477
NSN 5990-00-934-3145
NSN 6135-00-728-9860
NSN 6105-00-869-3353
NSN 5910-01-462-1205
NSN 5915-01-220-9560
NSN 6130-01-079-3712
NSN 5905-01-150-1894