U Steel Beam Arch for Coal Mine 1.We are manufacturer 2.It is made of U25 ... , SGS Certification U Steel Beam Arch for Coal MineU type steel support main purpose: for mine tunnel, mine tunnel secondary support, and mountain tunnel ... .U25,U29,U36 type steel frame. U Steel Beam Arch for Coal Mine features:1.Spec.: 25U, 29U, 36U 2.Standard:GB/QB ... our samples of U steel arches U Steel Beam Arch for coal mine