Composition 4 material stress relieved per specification mil-b-857a ships
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.)
Classification: Copper screws, nuts, bolts, rivets, and other fasteners not threaded
NSN 4140-01-276-8307
NSN 5905-00-842-2232
NSN 5999-01-463-2867
NSN 5915-00-304-8195
NSN 5920-00-702-6694
NSN 6110-01-619-9301
NSN 6220-00-632-6469
NSN 5945-01-529-5607
NSN 5915-01-579-4810
NSN 6240-01-218-5187
NSN 5990-01-353-3691
NSN 5855-01-180-5369