Galvanized pipe is deeply rooted in the steel bar profile industry, and is deeply loved by everyone. However, when purchasing galvanized pipe, we must master some skills to distinguish the advantages and disadvantages of products, so as to help us choose the best steel when purchasing.
1. Fake and inferior galvanized pipe is easy to be scratched. The reason is that the manufacturer's equipment is simple and easy to produce burr and scratch the steel surface. Deep scratch reduces the strength of the steel.
2. The fake and inferior galvanized pipe has no metallic luster and is light red or similar to pig iron color.
3. The transverse reinforcement of fake and inferior galvanized pipe is thin and low, and the phenomenon of insufficient filling often occurs. The reason is that in order to achieve large negative tolerance, the reduction of the first few passes of the finished product is too large, the iron mold is too small, and the pass is not fully filled.
4. The cross section of the fake and inferior galvanized pipe is oval. The reason is that in order to save materials, the reduction of the first two passes of the finished roll is too large, and the strength of the pipe is greatly reduced, and it does not conform to the standard of the external dimension of the steel pipe.
5. The composition of the galvanized pipe is uniform, the tonnage of the cold shear is high, and the end face of the cutting head is smooth and neat. However, due to the poor quality of the galvanized pipe, the end face of the cutting head often has the phenomenon of falling off, that is, uneven and without metallic luster. And because of the fake and inferior products cut less, head and tail will appear big ears.
6. The fake and inferior galvanized pipe material contains many impurities, the density of steel is too small, and the size is out of tolerance seriously, so it can be weighed and checked without vernier caliper. Generally speaking, the whole phase weighing effect will be better, mainly considering the cumulative error and probability theory.