The present disclosure relates to a pair of screw elements suitable for a multishaft screw machine with m screw shafts SW.sub.1 to SW.sub.m rotating in the same direction and at the same speed, the respective neighboring axes of rotation X.sub.1 to X.sub.m of which have a center distance A in a cross-section at right angles to the axes of rotation, and with m interpenetrating circular housing bores which each have an identical housing bore inner diameter D and of which the bore centers M.sub.1 to M.sub.m have a distance equal to the center distance A, and of which the bore centers M.sub.1 to M.sub.m coincide with the respective associated axes of rotation X.sub.1 to X.sub.m of the screw shafts SW.sub.1 to SW.sub.m and coincide with the centers of rotation P.sub.1 to P.sub.m of the screw elements.

An extruder screw including an elongated cylindrical tension rod; screw segments including radially protruding functional elements configured to feed, mix, and/or knead an extrudate, and a respective pass through bore hole oriented in a longitudinal direction of the extruder screw, wherein the screw segments are slid onto the tension rod with the pass through bore hole and axially supported at a tip of the tension rod; a counter element that clamps the screw segments against the tip of the tension rod at an end of the tension rod wherein the end is arranged distal from the tip; and a locking element that is clamped between the screw segments and the counter element.

A method for producing a polycarbonate resin composition pellet with a twin screw extruder, the polycarbonate resin composition pellet has 30 to 95 mass % of a resin pellet (A) containing more than 40 mass % of a polycarbonate resin in the pellet; not less than 5 mass % and less than 40 mass % of a phosphate ester flame retardant (B) that is a liquid at room temperature; 0 to 50 mass % of polycarbonate resin flake (C); 0 to 30 mass % of an ABS resin (D); and 0 to 15 mass % of an additive (E) other than component (B). The method includes feeding components (A), (C), (D) and (E) in a twin screw extruder and kneading with a first kneading zone; feeding component (B) to a downstream part in the first kneading zone and kneading with a second kneading zone; and decompressing a vent in the downstream part in the second kneading zone.