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 5998-01-634-0604
NSN 5920-01-013-8594
NSN 5855-00-925-0114
NSN 5990-00-127-5584
NSN 7035-01-145-5059
NSN 5990-01-537-1124
NSN 5920-00-451-0463
NSN 5960-00-064-2952
NSN 5905-01-442-6887
NSN 6130-00-365-4572
NSN 6610-01-548-7604
NSN 6685-00-752-4429