Technical Approach to Prevention of Longitudinal Spiral Eccentricity in Tail End of Cold-drawn Light-wall Seamless Steel Pipe

With consideration of the characteristics of the manufacturing process for cold-drawn light wall seamless steel pipes,the deformation process of the pipe as being drawn over the mandrel is analyzed. Also elaborated are the causes responsible for the so-called “tail swing” as occurs during drawing of the pipe,and the negative influence thereby on the said spiral eccentricity. Meanwhile,practical actions are proposed to prevent the above mentioned eccentricity of the cold-drawn pipe in terms of the cold-drawing process and design of the dies.