A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5905-00-721-0118
NSN 5905-01-025-7454
NSN 5905-01-557-5395
NSN 5998-00-010-1445
NSN 6110-01-258-6343
NSN 6220-00-458-4633
NSN 2925-00-899-4261
NSN 5835-01-608-3319
NSN 5985-01-603-6974
NSN 5965-00-164-8092
NSN 5920-01-560-9487
NSN 5950-00-225-8557