MetricChrome vanadium steel (except * which are made from drop forged carbon steel) with a satin finish body and highly polished heads, with a 15° offset.DIN 3110: 4 x 5mm to 32 x 36mm.ASME B107.39: 36 x 41mm to 46 x 50mm* 36 x 41, 41 x 46, 46 x 50mm Made from drop forged carbon steel.