heavy rail U71Mn U71 45Mn 50Mn ISO9001 ASTM AI JIS E 1103/ ... -200844.6531050kg/mU71Mn/U71/45MnGB2585-2007 Q/YYG002-200851.514101 Light rail:(type)6kg/m, 8kg/m,12kg/m, 15kg/m,18kg ... , 43kg/m, 50kg/m, 60kg/m (quality)U71Mn 50Mn3 Crane light rail:(type)QV70, QV80, QV100, QV120 (quality)U71Mn4 japan/Korea standard ...