| 摘要 |
<p>The present invention concerns an improved mandrel (4) for forming metal materials, polymers or composites by extrusion which consists of a rotary cylindrical mandrel with alternate bulges and recesses along its longitudinal axis respectively defining the working parts (12) of a calibrated diameter and recessed areas (13) for a lubricant suitable for the extrusion rate and nature of the extruded material. It is applicable in particular to the manufacture of metal tubes.</p> |
