Spiral welded pipe: It is made by rolling low-carbon carbon structural steel or low-alloy structural steel strip into a pipe blank at a certain angle of the spiral line (called the forming angle), and then welding the pipe seam together.Specification:10MM---720MM customizable,Tolerance (Mm):Width±0.02; Thickness±0.02; Wall Thickness±0.02; Processing Methods:Hot Extrusion / Extrusion Forming.