In the through-flow mixer according to the invention having a novel neck bearing, the axle furnished in the dry zone with a metering screw is guided on the driving side by the drive motor and on the power take-off side by the novel neck bearing. A protective tube provided with stirrer tools which is welded to the axle on the power take-off side and on the driving side engages in a lip seal permits no material to be mixed to penetrate into the neck bearing. The mixer tool axle of the wet zone is held and driven via a simple push-in connection by the mounted axle of the dry zone.
