PURPOSE: To prevent the development of peeling caused to development of miss roll by arranging a fixed guide at between each disk roll and cross helical roll and bringing the fixed guide into sliding contact with outer peripheral face of a material to be rolled.

CONSTITUTION: A solid billet B heated to the prescribed temp. with a heating furnace is shifted as matching this axis to pass center X-X from inlet 12 side of the cross helical rolls 1, 1. At first, the tip part is bitten in between the inlet parts 12, 12 in the cross helical rolls 1, 1 and after that, while shifting as screwing with rotation of both cross helical rolls 1, 1 along the pass center X-X with the disk rolls 3, 3 and the fixed guides 4, 4, the intermittent rolling reduction is received at one time per half rotation at between plug 2 inserted into the axial position and the cross helical rolls 1, 1 and the billet is pierce- rolled. At the time of receiving no rolling reduction, the billet B is bulged outward to the radius direction with the rotation, but the disk rolls 3, 3 and the fixed guide roll is brought into sliding contact with the outer periphery of bulged part and the bulging to outside can be restrained.