English: C-frame milling machine modified for friction extrusion. At left is an overview image and at right is a close up of the mechanical spindle which provides die rotation and the hydraulic cylinder that provides the extrusion pressure. Wire is extruded vertically through the hollow draw bar of the milling machine. This configuration corresponds to a direct extrusion with a rotating die: i.e. the charge (billet in this case) is pushed into the rotating die.