Also known as square and rectangularcoldbendinghollowsection,referredtoas "square and rectangulartubes,code FandJ,respectively 1,theallowable deviation in thewallthicknessofthemoment, when thewallthickness is not more than 10mmshallnotexceedthe nominal wallthicknessof plus or minus10%,whenthewallthickness is more than 10mm for thewall thicknessofplusorminus8%, except corners and weldarea wallthickness.2,thetorquetubeusually delivery length is 4000 mm- 4000 mm,6000 mmand12000mminthe majority. Torque tube allowdelivery notlessthan2000mmshortfeet and the length of theproduct,canalsointerfacetubeformdelivery, but the buyer whenuseinterfacetubeshouldberemoved.Short feet and non scale product weightisnotmore than5%ofthetotal amount of delivery, fortheoreticalweightgreaterthan20kg/msquare torque tube shall not exceed10% ofthetotalamountofdelivery3, square torque tube bending shall notbegreaterthan2 mmpermetre,total bending shall not be greater than 0.2%ofthetotal length