A method of processing metal, metallic alloys, and metal matrix composites in a plastics injection molding machine is disclosed. The method includes the steps of providing a plastics injection molding machine having a screw. A step of removing the screw is included in the method. A step of replacing the screw with a modified screw configured and arranged for processing metals is also included. Alternatively, a step of removing the flights from the middle portion of the original screw shaft may be included.