in the early stage of the steel pipe industry, the trick of cheating is much more, but now people are more proficient in this industry, so those means can be identified under our naked eye.
1. the thickness of the steel pipe is not enough to use the gate means, the mouth of the steel pipe looks thicker with the iron hammer shield, but it will be exposed with the appearance of the instrument.
2. with straight seam as seamless steel pipe, straight seam weld is less on a longitudinal weld, using machine to wear the whole steel pipe, commonly known as polishing, looking at the same as no gap to act as seamless.
several points to be paid attention to in the procurement of anticorrosive steel pipes
3. there is a more sophisticated way now is seamless steel pipe, seamless steel pipe, that is, the expansion of the steel pipe. after the expansion, there is the lead powder inside, there is also a burning trace outside the weld is also invisible, many of the larger steel pipes used to act as seamless to sell, to seek large profits.
飞艇手机免费计划4. girth weld anticorrosive steel pipe is used for polishing seamless steel pipe.