1. The raw materials come from different manufacturers, indicating that the prices of raw materials are different.
2. For suppliers with different technologies and high prices, they will first examine whether the raw materials are checked and what inspections they need, such as chemical composition inspection, pickling, and appearance inspection. If there is no problem, cut the head and then roll and polish it. After the processes of cold drawing or cold rolling, then conduct pickling, heat treatment, straightening, and then the cutting of the head again. Finally, pickling should be done again, and the ultrasonic inspection, eddy current inspection, surface size inspection, or water pressure inspection are required.
So those suppliers with seamless stainless steel tube at low prices may omit a lot of processes. The first is that raw materials are not rolled and polished. Here, nearly 1,000 yuan can be saved for one ton. Why can it save so much cost? The reason is that rolling and polishing will lead to product loss and cost of labor. The heat treatment of raw materials that are not rolled and polished will cause the contaminants and oil to fuse with the seamless stainless steel tube itself, which will lead to unqualified mechanical properties and uneven surfaces. The products with a low price in pickling only need to be washed once, and the cost of pickling is 400 yuan per ton each time, and therefore another 800 yuan per ton can be saved here. The head cutting is also not fully conducted, which will result in unqualified outer diameter or thickness. What's more, those suppliers will basically not have inspections. Then these inspections can save them nearly 1,500 yuan/ton in cost.
Therefore, it is normal that the price difference of suppliers is so great, which can even reach 3,000 yuan per ton. In this way, suppliers with low prices have a very low pass rate, and they don't know how many seamless stainless steel tube products are qualified or unqualified.
Do you understand all above? If you have any questions, welcome to consult us at any time. Thanks.
Here are the piercing processes of seamless pipes/tubes: