Suqiao Non-standard Seamless Steel Pipe refers to seamless steel pipes with cross-sectional shapes other than circular. According to the different dimensions of the steel pipe cross-section, they can be further divided into Equal Wall Thickness Non-standard Seamless Steel Pipes (code D), Unequal Wall Thickness Non-standard Seamless Steel Pipes (code BD), and Variable Diameter Non-standard Seamless Steel Pipes (code BJ).

Special-shaped seamless steel tubes are widely used in various structural components, tools, and mechanical parts. Compared to round tubes, special-shaped tubes generally have larger inertia moments and section moduli, offering greater bending and torsional resistance. This can significantly reduce structural weight and save on steel.