Quality of Non-standard P-shaped tube, P-tube model, Gaotong customizes non-standard P-tubesSpecial-shaped steel tubes, including octagonal pipes and rhombic pipes.[1]  Elliptical tubes and other shapes. These are economic cross-section steel pipes, including those with non-circular cross-sectional contours, uniform wall thickness, variable wall thickness, varying diameter and wall thickness along the length, and both symmetrical and asymmetrical cross-sections. Examples include square, rectangular, conical, trapezoidal, and helical shapes. Special-shaped steel pipes can better adapt to the specific conditions of use, save metal, and increase the labor productivity of parts manufacturing. They are widely used in aviation, automotive, shipbuilding, mining machinery, agricultural machinery, construction, light industry and textiles, as well as boiler manufacturing. The methods of producing special-shaped seamless steel pipes include cold drawing, electric welding, extrusion, and hot rolling, with cold drawing being the most widely applied.