A nut, flat on top and bottom, having 4 flat sides. For items having a thickness (or height) exceeding two times the width across the flats, use post, electrical-mechanical equipment. (when height or thickness and/or width across the flats is designated as a tolerance dimension, the maximum dimension will be used to determine compliance.)
NSN 5990-00-424-1598
NSN 6685-00-652-2657
NSN 7035-01-419-1462
NSN 5960-01-202-6610
NSN 6150-01-144-8953
NSN 6105-01-500-0891
NSN 5960-00-583-4902
NSN 5935-01-621-1134
NSN 5930-00-050-9525
NSN 5855-01-003-7102
NSN 2925-01-300-6602
NSN 4140-01-492-4797