1. Fake steel pipes are prone to fold.
Folding is a variety of lines formed on the surface of steel tubes, which often penetrate the entire product longitudinal. The reason for the folding is due to the high efficiency of shoddy manufacturers, under the pressure of a large quantity, produce Rzi, the next rolling in the fold, folding products will be cracked after bending, the strength of the steel drop.
2. Fake steel pipes often have the appearance of the phenomenon.
The defects of the uneven surface of the steel are caused by the abrasion of the groove. Because of shoddy steel pipe manufacturers to pursue profits, often appear rolling trough the most exceeded.
3. The surface of shoddy steel pipes is prone to scarring.