Commonly used materials for welded pipes are: Q235A, Q235C, Q235B, 16Mn, 20#, Q345, L245, L290, X42, X46, X60, X80, 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb, etc.

With the rapid development of continuous rolling production of high-quality strip steel and the advancement of welding and inspection technology, the quality of welds has been continuously improved, the varieties and specifications of welded steel pipes have been increasing, and seamless steel pipes have been replaced in more and more fields. Welded steel pipes are divided into straight seam welded pipes and spiral welded pipes according to the form of the weld. Classification by production method: process classification - arc welded pipe, electric resistance welded pipe, (high frequency, low frequency) gas welded pipe, furnace welded pipe.

The blanks used for welded steel pipes are steel sheets or strips, which are divided into furnace welded pipes, electric welded (resistance welded) pipes and automatic arc welded pipes due to their different welding processes. Due to the different welding forms, it is divided into two types: straight seam welded pipe and spiral welded pipe. Because of its end shape, it is divided into circular welded pipe and special-shaped (square, flat, etc.) welded pipe.