The main trend in the world’s pipe rolling production is the use of a continuous longitudinal rolling mill in a pipe-rolling line. In such mills, shells are rolled into pipes using long cylindrical mandrels, which are subject to severe temperature and force conditions. In addition, mandrels are the most expensive tool of continuous mills. The wear of mandrels during rolling, producing different wall thickness with a mandrel of the same diameter, and producing the same wall thickness with mandrels of different diameters necessitate adjusting the position of the rolls in the mill stands.

The adjustment of the position of the rolls in the stands of a mill is known to lead to changes in the wall thickness and the formation of defects on the surface of the mother pipe, which affects other parameters of the process. This necessitates experimental study into the process of longitudinal rolling of pipes in order to evaluate the effect of the mandrel diameter on the accuracy of pipes, the angle of contact between the mandrel and the metal, and the overfill of the groove. The defects caused by the irrational choice of the diameter of a cylindrical mandrel are characterized. Lead was used as a model material for making samples during the study.

世界管道轧制生产的主要趋势是在管道轧制线上使用连续纵向轧机。在这样的轧机中，使用长圆柱形心轴将壳体轧制成管子，这些心轴要经受严酷的温度和作用力条件。此外，心轴是连续磨机中最昂贵的工具。轧制期间心轴的磨损，使用相同直径的心轴产生不同的壁厚以及使用不同直径的心轴产生相同的壁厚需要调整轧辊在轧机机架中的位置。

轧机在轧机机架中的位置的调整已知会导致壁厚的变化以及在母管表面上形成缺陷，这会影响工艺的其他参数。为了评估心轴直径对管道精度，心轴与金属之间的接触角以及沟槽的过度填充的影响，需要对管道的纵向轧制过程进行实验研究。表征了由不合理选择圆柱心轴直径引起的缺陷。在研究期间，铅被用作制作样品的模型材料。