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 6620-01-290-2973
NSN 5960-00-264-5233
NSN 5855-01-535-7127
NSN 6645-01-341-3436
NSN 5855-00-149-0766
NSN 5996-01-508-2467
NSN 5925-01-357-5560
NSN 6645-00-348-2841
NSN 6130-00-257-5599
NSN 6135-00-268-8492
NSN 6150-00-624-3201
NSN 6150-01-559-4019