The square tube is bent into an arc by hand, and the bending moment is formed by the unidirectional contact between the outer roller and the outer wall of the tube blank, so that the strip is bent. Empty bending will compress the bending line, and the compression effect will lengthen the bending line longitudinally, and the metal at the bending point will accumulate and thicken, which is the compression thickening effect of empty bending.

1, bend 100 60 square pipe. If the pipe wall is too thin, you can put sand in the pipe and bend it again. Bend by hand, preferably with a bending die.

2. Square tube It is a square section steel with Q235 hot-rolled or cold-rolled strip or coil as the base material, which is made after cold bending and high-frequency welding.

3. The corner size and edge straightness of hot-rolled ultra-thick-walled square tube reach or even exceed the level of resistance welding cold-formed square tube, but the wall thickness is thickened. Good comprehensive mechanical properties, weldability, cold and hot workability and corrosion resistance, and good low temperature toughness.