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 5998-00-587-3341
NSN 5998-00-691-6070
NSN 5920-01-287-3343
NSN 6135-01-468-6491
NSN 5835-00-023-0780
NSN 6610-01-003-5794
NSN 6145-01-315-4263
NSN 6145-01-566-0756
NSN 6610-00-216-6538
NSN 4140-00-501-7833
NSN 6650-01-429-9242
NSN 5905-01-421-3156