M30 Hex Nut - A2 Grade A2 stainless steel has good resistance to corrosion except in severe industrial and Marine Condition. Use A4 in a marine environment. Thread Pitch - 3.5 mm Where: e = point to point m = thickness s = across flats d = Thread e - 50.85 mm (min) m - 22.7 mm (min) s - 46 mm d - M30 DIN934