The non standard steel pipe is a kind of steel pipe which is compared with the national standard for the seamless steel pipe
except the state standard. In the production of seamless steel pipe, the thickness of the wall thickness is classified according to the national conventional requirements and the thickness of the wall is classified, and it is allowed to have certain errors, which belongs to the national standard. In practical use, the national standard often has some limitations, which corresponds to the appearance of non-standard seamless steel tubes. The specifications of non-standard steel pipes complement the standard standard seamless steel pipe production, not that the quality of seamless steel pipe is compared to the national standard.
In the production of non standard steel pipe, some national standard seamless steel pipe
or round steel are produced as pipe material. Because of small sales volume, the price is often higher than the ordinary national standard seamless steel pipe, but the non-standard seamless steel pipe is also malpractice, because there is no fixed standard requirement, some manufacturers use seamless steel tube as seamless tube or defective tube, so the price of seamless steel tube is used as a seamless tube. It's much cheaper. Therefore, the price of non-standard seamless steel pipe is often unstable, and the quality of products is also uneven.