A stuffing screw (2) for use in an extruder system comprises a housing (7) and at least one screw conveyor (5) mounted rotatably inside the housing (7), wherein a conveying space is formed between an inner side of the housing (7) and the screw conveyor (5). The stuffing screw (2) is characterized in that the inner side of the housing (7) is provided, at least in one section, with one or more depressions, in particular in the form of a groove (13).