PURPOSE: To prevent a mandrel from an occurrence of partial abrasion, by controlling the mandrel position in the circumferential direction so that the number of rollings of the mandrel surface opposing to a rolling roll is made uniform at any point on the mandrel circumference in case of performing a large number of rollings with the same mandrel.

CONSTITUTION: A mandrel is rotated in the circumferential direction by driving a turning roll 5 through a rotary machine 6 with the aid of a controlling device 8, and a projecting part 2 at the neck part of the mandrel 1 is detected by a standard position detector 3 to put the part 2 as a standard position of the mandrel 1. On the other hand, a preset counter 10 is adjusted back to the intial position by an aimed rotating quantity setter 9 which is used for setting the mandrel 1 to a prescribed position. A rotated quantity of the mandrel, counted from the point of time that the detector 3 generates a detecting signal 4, is detected by inputting a signal 12 outputted from a rotating quantity detector 7 to an operator 10, and a stopping command 11 is outputted to a rotary machine controlling device 8 at the point of time when the preset value of the setter 9 coincides with said rotated quantity to stop the mandrel 1 at the prescribed position.