Extruder screw for a screw extruder

The invention concerns an extruder screw for a screw extruder for plasticizing and/or transporting thermoplastic materials comprising at least one extruder cylinder, a material feed means and at least one extrudate discharge at the end of the extruder cylinder, that is remote from the material feed means. The extruder screw has a screw flight, wherein the extruder screw has at least one intake region and forms at least one transport and mixing region and provided in the transport and mixing region are means for shearing the extrudate. The extruder screw according to the invention is distinguished in that provided as means for shearing the extrudate there is provided at least one shearing land which extends over more than half the length of the extruder screw, over the periphery of the extruder screw, wherein the shearing land is in the nature of a screwthread in opposite relationship to the screw flight.