A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6685-01-630-3146
NSN 5905-01-322-5490
NSN 5996-01-622-3519
NSN 6320-01-476-7476
NSN 5965-00-424-9636
NSN 5975-00-098-0131
NSN 5925-01-264-7296
NSN 5965-00-351-7460
NSN 5998-00-351-5736
NSN 6110-00-793-9803
NSN 5985-01-461-9895
NSN 6645-01-315-9238