1. Coarse thick-walled steel pipe is easy to fold.
2. Thick-walled steel pipe surface is not good, easy to leave scars.
3. The surface of fake and inferior materials is easy to crack.
4. Pseudo-thick-walled steel pipes are easy to scratch.
5. Coarse thick-walled steel pipe, no metallic luster, light red or similar pig iron.
6. The small cross ribs of counterfeit thick-walled steel tubes often appear dissatisfaction.
7. The cross section of pseudo-thick-walled steel tube is elliptical.
8. Pseudo-thick-walled steel pipe material contains impurities and steel density is too small.
9. Diameter size fluctuation of forged thick-walled steel tube.
10. The quality control of trademark and printing is more standardized.
11. Three large diameter pipes are 16 or more in diameter, and the spacing between the two trademarks is above IM.
12. Longitudinal reinforcement of fake and inferior steel bars is usually wavy.
13. Fake thick-walled steel pipe manufacturers do not drive, so the packaging is looser. Both sides are oval.