A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5945-01-452-1067
NSN 5925-00-905-5135
NSN 5975-00-465-6397
NSN 6645-01-034-6037
NSN 5910-00-544-7448
NSN 5905-01-622-2933
NSN 5990-00-155-2306
NSN 2925-01-271-6234
NSN 5999-01-068-8749
NSN 5996-00-851-5802
NSN 6610-00-811-6072
NSN 5920-01-218-1733