Part number 13-010-052 on the nsn is a bolt
A nut, flat on top and bottom having 6 flat sides. For items which have internal tapered or straight (parallel) pipe threads, specific electrical conduit size designation, and which when installed, provide a method of tightening to lock the connection, see locknut, electrical conduit. See also locknut, tube fitting. 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 5925-01-222-6638
NSN 5905-01-218-2285
NSN 5996-00-707-6228
NSN 6110-01-518-3318
NSN 5996-00-121-7677
NSN 5905-00-280-2747
NSN 6645-01-119-3496
NSN 5855-01-444-1233
NSN 6645-00-083-6853
NSN 5950-00-670-0402
NSN 2925-01-327-3069
NSN 5990-01-011-0683