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 5930-00-922-6491
NSN 5985-00-243-4160
NSN 5990-01-370-7912
NSN 5915-01-437-2962
NSN 5905-01-169-6374
NSN 5950-00-734-9281
NSN 5930-00-161-5101
NSN 6110-01-478-4084
NSN 4140-01-545-4301
NSN 2925-01-394-9658
NSN 5930-01-258-3454
NSN 5985-01-097-4060