U-Beam steel for mine timbering Spec.: 25U, 29U, 36U Standard:GB/QB Materials: 20MnK, Q275 Length: 8,9,10,12m U-Beam steel for mine timberingSpec.: 25U, 29U, 36U Standard:GB/QB Materials: 20MnK, Q275 Length: 8,9,10,12mit is mainly used for mining tunnel support ,with the features of high presure long fit strong structure. U-Beam steel Arch