1, the allowable deviation of the thickness of the square tube, when the wall thickness of not more than 10mm shall not exceed the nominal wall thickness of plus or minus 10%, when the wall thickness greater than 10mm for the wall thickness of plus or minus 8%, angle and weld area Wall thickness excepted.
2, rectangular tube usually delivery length of 4000mm-12000mm, to 6000mm and 12000mm majority. Rectangular pipe to allow delivery of not less than 2000mm short and non-scale products, can also be delivered in the form of interface pipe, but the demand side should be used in the removal of the interface tube. Short and non-cut length of the product weight does not exceed 5% of the total delivery, the theoretical weight greater than 20kg / m square tube should not exceed 10% of the total volume of delivery.
3, the bending moment of the square tube shall not be greater than 2mm per meter, the total curvature of not more than 0.2% of the total length.