Nozzle for guiding molten metal, including an inlet at an upstream first end, at least one outlet towards a downstream second end, and an inner surface between the inlet and the outlet defining a bore through the nozzle having a throat region adjacent the inlet. An annular channel is provided in the inner surface of the nozzle, and a fluid supply is arranged to introduce fluid into the bore via the annular channel or downstream thereof. The throat region has a convexly curved surface and the annular channel is located within or adjacent the convexly curved surface of the throat region.