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 6220-01-113-9952
NSN 6685-00-329-7010
NSN 5999-01-173-2774
NSN 5985-00-248-4978
NSN 5990-01-481-8441
NSN 6650-01-145-5173
NSN 6130-01-600-0763
NSN 5925-01-150-8127
NSN 5960-01-210-0879
NSN 6620-00-144-7201
NSN 5905-01-607-5985
NSN 5925-00-612-7159