... Mild Steel Black Square Tube Material: Q195 ,Q235,Q235 Sizes: 15x15mm to 500x500mm Thickness:0.5-25mm Length: 1-12m Square Tube/ ... BV certificate,PC certificate,ISO9001-2000,SGS inspection. Steel Square TubeSquareDimension: 10mm*10mm-400mm*400mmRectangular Dimension: 10mm*20mm-350mm ... -92, GB/T6728-2002MaterialsQ195,Q215,Q235,Q345TechniqueERW Welded square tubePacking1.Big OD:in bulk2.Small OD:packed by ...