Also known as square and rectangular cold bendinghollowsection,referredto as "square and rectangular tubes, code FandJ,respectively 1,the allowable deviation in the wall thicknessofthemoment, when thewall thickness is not more than 10 mm shallnotexceedthe nominal wallthickness of plus or minus 10%, whenthewallthickness is more than 10mm for the wall thickness of plusorminus8%, except corners and weldarea wall thickness. 2, thetorquetubeusually delivery length is 4000 mm- 4000 mm, 6000 mm and 12000mminthe majority. Torque tube allowdelivery not less than 2000mmshortfeet and the length of the product,can also interfacetubeformdelivery, but the buyer when use interfacetube shouldberemoved.Short feet and non scale product weight is notmore than 5%ofthetotal amount of delivery, for theoretical weightgreater than20kg/msquare torque tube shall not exceed 10% of the totalamountofdelivery3, square torque tube bending shall not be greater than2 mmpermetre,total bending shall not be greater than 0.2% of the total length