12# Mining I-Beam can be used for mine tram road size:9#, ... #,20# Materials:Q235 Length:8,9,10 standard:ISO9001:2000 I-Beam 12# can be used for mine tram road size ... 38-50 KGS/M, the crane rail of QU70QU80QU100 & QU120, I-beam of the mine usage steel of 9#11# & 12 ... consumers from now on more than ten years. 12# Mining I-Beam