A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6645-00-755-9782
NSN 5835-01-381-2683
NSN 7035-00-756-4374
NSN 6135-01-142-6456
NSN 5960-01-052-9577
NSN 5999-01-256-6023
NSN 5950-01-163-6566
NSN 5945-01-437-5401
NSN 6145-01-408-5004
NSN 6650-01-399-8552
NSN 6150-01-021-8089
NSN 6240-00-905-7512