... *4.5mm-400*104*14.5mm length:6m,9m,12m U channel1.Material:Q235,Q195,Q345,SS400,ASTMA362.Standard:GB,ASTM ... :50mm*37mm~400mm*104mm5.ISO9001 Quality System Certificate 6.Aplication: Construction,large-span,metal structure,/towercrane, water heating, electrical installation and ...