Used on a tactical police shotgun
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 5999-01-250-8815
NSN 5930-01-442-6723
NSN 5905-00-816-3536
NSN 6610-01-175-9045
NSN 5905-01-599-7885
NSN 5855-01-282-4881
NSN 2925-00-881-3770
NSN 6130-01-147-5594
NSN 6650-01-017-0980
NSN 5999-00-340-1364
NSN 5945-01-441-9370
NSN 5985-01-065-0959