A washer or cone or disk shape with a centrally located hole, designed to accommodate a flat or oval head screw and provide additional bearing area on the material being fastened. It may or may not have a flush flange feature.
NSN 6650-01-399-0628
NSN 5945-01-284-0396
NSN 5910-01-590-4506
NSN 5915-00-757-2664
NSN 7035-01-459-7545
NSN 6130-01-350-3585
NSN 6320-01-220-2264
NSN 5925-00-708-8769
NSN 5855-01-503-3452
NSN 6240-01-444-1673
NSN 5985-01-386-4419
NSN 5835-00-884-4480