Abstract: A honeycomb extrusion die comprising a die body incorporating an inlet face, a discharge face opposite the inlet face, a plurality of feedholes extending from the inlet face into the body, and an array of intersecting discharge slots extending into the body from the discharge face and interconnecting with the feed holes, the intersecting discharge slots being formed by the side surfaces of a plurality of pins bounded by the slots and extending into the die body from the discharge face, wherein a plurality of the pins include one or more multi-textured side surfaces, each side surface including at least two surface regions differing in surface finish from each other.

Abstract: In a metal honeycomb extrusion die which incorporates apertures for the conveyance of extrudable material through the die body toward a discharge opening in the face of the die, the aperture sidewalls are shaped by electrochemical machining or the like to develop a periodically varying aperture size, surface shape or surface finish, superimposed on the conventional randomly varying machined aperture sidewall surface, in order to reduce the adverse effects of random surface variations on extrusion process stability and extruded product quality.

Abstract: A steel honeycomb extrusion die having an array of feedholes extending into a die inlet face and intersecting with an array of discharge slots on the die discharge face is made by a process wherein the slots are cut into blind feedholes by wire EDM slotting while dielectric fluid is provided in or flushed through the feedholes. The resulting improvements in EDM process stability reduce the number of wire electrodes broken during machining of the array, and in feedhole/slot intersection configuration and finish, provide dies with improved extrusion performance and extended service life.

Abstract: A process of electrolytic machining holes of uniform diameter in a conductive workpiece, particularly one having a slotted lower portion. Drilling is accomplished electrochemically by providing a conductive tube, passing an electrolytic fluid through the tube to the workpiece, and passing a DC current between the tube and the workpiece through the electrolyte. The DC current causes material from the workpiece to "deplate" into the electrolyte, resulting in the formation of the hole. Hole diameter is made uniform by maintaining the supplied DC current constant, despite sudden changes in the conductivity of the electrolyte, the workpiece or both.

Abstract: The present invention is directed to a shaped-tube electrolytic polishing process which involves providing a workpiece with at least one hole. The hole is polished by advancing a metal tube electrode through the hole while passing an electrolyte through the tube and into the hole and while passing electric current between the metal tube and the workpiece through the electrolyte. As a result of such polishing, reduced surface roughness is imparted to the hole. It is particularly desirable to provide the hole in the workpiece by a shaped-tube electrolytic drilling process.