LSAW steel pipe is a welded pipe produced by pressing (rolling) a single medium and thick plate into a tube blank in a mold or a forming machine, using double-sided submerged arc welding and expanding its diameter.

High frequency resistance welded pipes are widely used. The produced steel pipe requires straight welds, no burrs, and no defects such as cracks, cracks, and unwelded welding, and the surface of the steel pipe does not exceed the specified scratches, pressure injuries and other defects.

Thick-walled seamless square pipe is a square steel pipe with four corners, which is a square steel pipe formed by cold drawing and extrusion of seamless steel pipe.

Straight seam steel pipe is a welded pipe with the weld seam parallel to the longitudinal direction of the steel pipe. According to the production process, it is divided into ERW steel pipe and LSAW steel pipe.

Cold-drawn precision seamless pipe is a kind of high-precision seamless steel pipe material processed by cold-drawing or hot-rolling. Due to the advantages of no oxide layer on the inner and outer walls of the precision steel tube, no leakage under high pressure, high precision, high finish, no deformation after cold bending, no flaring, no cracks in flattening, etc.Therefore, it is mainly used to produce products for pneumatic or hydraulic components, such as cylinders or oil cylinders.

In the manufacturing process of seamless steel pipes, it will be affected by various factors such as processes.When these factors disappear, if the above-mentioned effects and effects on the seamless steel pipe cannot be completely eliminated, and some of the effects and effects remain in the seamless steel pipe, such residual effects and effects are called residual stress.