export joist 1.light steel keel 2.the manufacturer 3.high quality 4.environmental aluminum keel light steel keel main joistSpecificatons:1. Main tee:38x24x3000/3600mm; 32x24x3000/3600mm2. Cross tee:32x24x1200mm;26x24x1200mm3. Cross tee:32x24x600mm; 26x24x600mm4. Wall angle:24x24x3000mm; 22x22x3000mm; 20x20x3000mm5. Thickness:0.25mm,0.27mm,0.3mm,0.35mm,0.4mm6. The length, thickness and color can ...