A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5925-01-368-3723
NSN 5990-01-258-3848
NSN 6645-01-558-5057
NSN 5920-00-515-3617
NSN 7035-01-498-4895
NSN 5996-01-167-9234
NSN 5895-01-122-5582
NSN 6220-00-934-9099
NSN 5835-00-907-0777
NSN 5905-01-307-0621
NSN 5985-01-020-8259
NSN 6110-01-160-5257