A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 7035-00-131-8219
NSN 5965-01-651-7274
NSN 5855-01-400-1590
NSN 5999-00-518-0462
NSN 6220-00-188-7525
NSN 5975-01-142-3190
NSN 6645-01-319-6583
NSN 5965-01-601-4413
NSN 6220-00-950-7477
NSN 7035-00-585-2113
NSN 6685-00-284-2244
NSN 7035-01-622-5984