M16 Hex Nut - A2 Grade - Fine Pitch Thread A2 stainless steel has good resistance to corrosion except in severe industrial and Marine Condition. Use A4 in a marine environment. Where: e = point to point m = thickness s = across flats d = Thread Thread Pitch - 1.5 mm e - 26.75 mm (min) m - 12.3 mm (min) s - 24 mm d - M16 DIN934