The production process of stainless steel square tubes and how to discern quality

Stainless steel square tubes are extruded from stainless steel round tubes. After undergoing heat treatment, flawless, crack-free, and unbent stainless steel round tubes are placed on the platform of rolling equipment for extrusion shaping. Subsequently, straightening processing is carried out. At this stage, quality inspectors conduct tests on mechanical properties, chemical analysis, tensile experiments, and other processes. Once confirmed, the tubes undergo saw cutting processing. Then, they proceed to mechanical grinding and polishing. Well-polished tubes are carefully packaged by packaging personnel using brand-new packaging materials, ready for direct shipment or warehousing.

What characterizes inferior stainless steel square tubes?

Inauthentic tubes exhibit irregular surface irregularities and defects. Due to profit pursuit, manufacturers of counterfeit tubes often compromise on surface smoothness.

Counterfeit tubes are prone to surface scarring due to two reasons:

(1) Material inconsistency and high impurity content.

(2) Poor equipment in counterfeit factories leads to steel adhesion, resulting in impurities.

Surface cracking is common in counterfeit materials due to the high porosity of the raw material, resulting in cracks during the cooling process and persisting through rolling.

Counterfeit tubes are susceptible to scratches because of the rudimentary equipment in such factories, often resulting in burrs that scratch the steel surface, thereby reducing its strength.

Irregular cross-sections characterize counterfeit tubes, usually due to excessive reduction in the initial rolling stages to save material. This compromises the strength of the tubes significantly and deviates from the standard dimensions of stainless steel square tubes.