export joist 1.light steel keel 2.the manufacturer 3.high quality 4.environmental aluminum keel light steel ... .27mm,0.3mm,0.35mm,0.4mm6. The length, thickness and color can be provided in accordance with customers' requirements.Component nameDescrptionThickness ... ,0.50Card light steel keel19x25mm0.619x28mmm0.8019x320.9019x38 1.0 the manufacturer's joist and keel