Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
B21B—ROLLING OF METAL
B21B17/00—Tube-rolling by rollers of which the axes are arranged essentially perpendicular to the axis of the work, e.g. "axial" tube-rolling
B21B17/08—Tube-rolling by rollers of which the axes are arranged essentially perpendicular to the axis of the work, e.g. "axial" tube-rolling with mandrel having one or more protrusions, i.e. only the mandrel plugs contact the rolled tube; Press-piercing mills
B21B17/12—Tube-rolling by rollers of which the axes are arranged essentially perpendicular to the axis of the work, e.g. "axial" tube-rolling with mandrel having one or more protrusions, i.e. only the mandrel plugs contact the rolled tube; Press-piercing mills in a discontinuous process, e.g. plug-rolling mills