Galvanized steel pipes are deeply rooted in the steel profile industry and are deeply loved by everyone. However, when we purchase galvanized pipes, we must also master some skills to distinguish the pros and cons of the products to help us choose high-quality steel when purchasing.
1. Fake galvanized steel pipes are easy to scratch. The reason is that the equipment of the manufacturers of inferior galvanized pipes is simple and easy to produce burrs and scratch the surface of the steel. Deep scratches reduce the strength of steel.
2. The shoddy galvanized pipe has no metallic luster and is light red or similar to pig iron.
3. The cross ribs of fake galvanized steel pipes are thin and low, and the phenomenon of dissatisfaction often occurs. The reason is that in order to achieve a large negative tolerance, the reduction of the first few passes of the finished product is too large, the iron type is too small, and the hole type is not full.
4. The cross-section of the shoddy galvanized steel pipe is elliptical. The reason is that in order to save materials, the manufacturer has a large reduction in the first two passes of the finished roll, and the strength of this pipe is greatly reduced, and it does not meet the standards of the external dimensions of the steel pipe.
5. The composition of galvanized pipe is uniform, the tonnage of the cold shear is high, and the end face of the cutting head is smooth and tidy. However, due to the poor material of the shoddy galvanized pipe, the end face of the cutting head often has meat loss, that is, it is uneven and has no metallic luster. Moreover, because of the few cuts of the shoddy products, big ears will appear in the head and tail.
6. The shoddy galvanized steel pipe material contains many impurities, the density of the steel is small, and the size is seriously out of tolerance, so it can be weighed and checked without a vernier caliper. Generally speaking, the effect of phasing weighing will be better, mainly considering the problem of cumulative error and probability theory.