M12 Galvanised Heavy Hexagon Nut - A194 Grade 2H tapped oversize Quenched & tempered carbon steel heavy hex nuts Since hot-dip galvanizing typically adds 2.2 to 5 mils of thickness to the threaded portion of a fastener, galvanized heavy hex nuts are tapped oversize to compensate for the corrosion resistant coating on the thread of the bolt Where: e = point to point m = thickness s = across flats d = Thread e - 21.10 mm (min) m - 11.57 mm (min) s - 18.67 mm (min) d - M12 Thread Pitch - 1.75 mm