Thick-walled pipe, a pipe called a square and rectangular tubing,like 200x200 steel square pipe which is the side looks like a pipe. After treatment process is rolled strip made. Generally the strip hot rolled steel coil after unpacking, smooth, curl, tube welding to form, and then rolled into the square tube by a tube and then cut into the desired length. Typically 50 per pack. Square hollow square tube, also known as cold-formed square and rectangular hollow sections, referred to as thick-walled square tube and square tube, code-named F and J.

1, square thick-walled square tube wall thickness tolerances schedule 40 square steel pipe, when the wall thickness of not more than 10mm nominal thickness shall not exceed plus or minus 10% of the time when the wall thickness greater than 10mm wall thickness plus or minus 8 percent, corners and weld areas except for wall thickness. 

2, Delivery normally square walled square tube length is 4000mm-12000mm, to 6000mm and 12000mm majority. Square hollow square tube to allow the delivery of not less than 2000mm length short ruler and non-product, can also form the interface tube delivery, but the demand side should be used in the interface tube removed. Short-foot length and weight of non-product does not exceed 5% of the total deliveries for the theoretical weight greater than 20kg / m square thick-walled square tube should not exceed 10% of total deliveries 

3, thick-walled square tube bending astm a500 grade b square steel pipe per meter shall not be greater than 2mm, the total curvature is not greater than 0.2% of the total length.

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