A decanter centrifuge for separating a supplied material in a light phase and a heavy phase comprising an elongate bowl arranged for rotation about its longitudinal axis, the bowl having a separation chamber with a circumferential wall, a screw conveyor being provided in the separation chamber and being coaxial with the bowl, the screw conveyor comprising a conveyor hub. The conveyor hub comprises a longitudinal tubular steel body part and a helical steel conveyor flight attached to the tubular steel body part. The conveyor hub further comprises an inner longitudinal body extending coaxially relative the longitudinal tubular steel body part. The inner longitudinal body is extending through at least a part of the tubular steel body and is made of a first material, such as carbon fiber reinforced epoxy, whose specific modulus is larger than specific modulus of the steel material of the tubular steel body part.