Jun 03, 2019 · The size of an extruder can be described by the three main factors: the screw diameter in mm the screw length in multiples of the diameter the drive power in kW. An extruder of type 45/35 (40kW) thus has a screw diameter of 45mm and a screw length of 1,620mm (45mm x 36). The drive power in this case is 40 kW. Extruder size, relevant data: