B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
B21B—ROLLING OF METAL
B21B13/00—Metal-rolling stands, i.e. an assembly composed of a stand frame, rolls, and accessories
B21B13/16—Metal-rolling stands, i.e. an assembly composed of a stand frame, rolls, and accessories with alternatively operative rolls, e.g. revolver stands, turret mills