A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6220-00-076-0428
NSN 5960-00-837-5146
NSN 5925-00-694-9607
NSN 6240-01-026-1376
NSN 5965-01-640-7104
NSN 2925-01-578-7731
NSN 6135-01-167-7604
NSN 5945-01-298-8337
NSN 5945-01-045-4011
NSN 5950-00-357-1594
NSN 6150-01-407-3186
NSN 6650-01-467-8818