A die is provided for extruding elongate particles suitable for use in catalysis. The die comprises a plurality of channels extending from an inlet to an outlet. From the inlet to the outlet each channel comprises a first section with a helical bore with a non-circular cross-section, and a second section with a cylindrical bore. The cylindrical bore of the second section which has a diameter equal or greater than that of the first section. The second section is at least twice as long as a diameter of the first section.