M12 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 Where: e = point to point m = thickness s = across flats d = Thread e - 21.10 mm (min) m - 9.64 mm (min) s - 19 mm d - M12 Thread Pitch - 1.75 mm DIN934