A screw for use in an extruder or in a twin screw extruder exhibits a mandrel and a number of segments held on the mandrel disposed axially to one another. Between the mandrel and a segment, a separate torque entrainer is disposed. The torque entrainer is in contact with the mandrel at a contact surface area of the mandrel, wherein the contact surface area is notch-free.To transmit the high occurring torque, the elements are connected to the mandrel in a positive-locking manner and also axially braced.