M20 Self Colour Heavy Hexagon Nut - A194 Grade 4 Quenched & tempered medium carbon-molybdenum heavy hex nuts Where: e = point to point m = thickness s = across flats d = Thread e - 33.53 mm (min) m - 19.48 mm (min) s - 29.67 mm (min) d - M20 Thread Pitch - 2.5 mm