The article describes a solution to eliminate spiral W.T. uneveness of the shell from the rotary piercer by means of modifying the roll taper and presents the calculating formula for the roll taper.

• 介绍了用改进穿孔机轧辊锥角解决毛管产生螺旋性壁厚不均的方法，给出了确定轧辊锥角的计算公式。