The disclosure relates to a three roll piercing mill made up of a roll stand for receiving the rolls in which the stand with the rolls is removed and carried from the mill to a roll removal and replacing station arranged normal to the direction of travel of the material rolled by the mill and adjacent to the mill. In the station there is provided a block having pins for supporting a used roll set and a new roll set, which block is rotated to position one or the other of these sets in registry with the removed roll stand.