M12 Galvanised Hexagon Thin Nut - Grade 4 - Din 439 Tapped Oversize 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 - 21.1 mm (min) m - 5.7 mm (min) s - 19 d - M12 Thread Pitch - 1.75 mm DIN439