export joist 1.light steel keel 2.the manufacturer 3.high quality 4.environmental aluminum keel light steel ... :0.25mm,0.27mm,0.3mm,0.35mm,0.4mm6. The length, thickness and color can be provided in accordance with ... ,0.50Card light steel keel19x25mm0.619x28mmm0.8019x320.9019x38 1.0 the manufacturer's joist and keel