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 6610-01-567-2765
NSN 6220-01-126-3586
NSN 6645-01-595-6165
NSN 5925-01-407-4105
NSN 6645-01-598-3976
NSN 6145-01-357-6288
NSN 5895-01-412-0950
NSN 5910-00-324-1862
NSN 5960-01-580-6360
NSN 6130-01-123-7586
NSN 6685-01-540-3220
NSN 5905-01-137-0858