Heavy Hex Nut Black Oxide

A six-sided internally threaded fastener which is both thicker and wider across the flats than a same sized finished hex nut. Nuts in sizes 7/16 & smaller shall be double chamfered. Larger sizes are either double chamfered or chamfered on top with a washer faced bearing surface. This is the strongest of all comparably-graded nuts because of its greater length of thread engagement and greater resistance to dilation (widening or stretching).