M30 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 - 50.85 mm (min) m - 13.9 mm (min) s - 46 d - M30 Thread Pitch - 3.5 mm DIN439