309S Steel Square Hollow Box is a kind of structural alloy steel, which is also stainless steel. 309S seamless steel tube is a common item. But for cross-country race with roll frameof the steel frame, 309S material is the best choice, on the premise of guarantee equal or even higher strength, frame made of 309S can be done slighter.

It is a tube type square body, many kinds of material can form a square body.Most steel square hollow box after unpacking, smooth, curly, circular tube is formed by welding, pipe rolling into square tube and then cut into required length.

Surface treatment classification of 309S Steel Square Hollow Box
1)Hot rolled pipe
2)Cold rolled tube

The most important thing is that the seamless steel pipe has high strength itself for mill state. its tensile strength is more than 700 mpa, yield strength is also very high. 309S steel pipe will fracture in pipe bending. Correct treatment after processing in the process of stress will be basically eliminated, and strong impact force point when there will be a instantaneous deformation.