A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5915-00-259-3772
NSN 5990-01-356-4259
NSN 5945-01-342-4501
NSN 6135-00-221-4720
NSN 5910-01-548-3098
NSN 5925-01-101-9480
NSN 6130-01-541-2512
NSN 6220-01-202-8907
NSN 6135-00-284-1406
NSN 6135-00-519-1325
NSN 5945-01-367-2754
NSN 7035-01-048-7122