M30 Hex Nut - A4 Grade A4 grade stainless steel has a greater corrosion resistance than A2 in certain environments. It is often used for Marine applications especially when coming into direct contact with salt water 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