A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5895-01-085-5471
NSN 6650-01-364-8504
NSN 5998-01-555-8650
NSN 5985-01-580-2835
NSN 5985-01-333-0910
NSN 5950-01-268-7827
NSN 6240-01-480-8996
NSN 6220-01-423-9491
NSN 6105-01-056-7511
NSN 5975-01-106-9555
NSN 5990-01-516-9665
NSN 6645-00-487-8044