The conical screws, unlike traditional versions, feature a particular geometry: a larger diameter near the reducer and a smaller one at the upper end. This structure creates a natural compression that increases the pushing force of the plastic material, proving particularly useful in applications with back pressure at the tip of the screws, improving the material processing efficiency.

The choice of material for the screws is closely linked to the quality of the mix of plastic materials to be processed. Generally, traditional nitriding steels are used, but depending on the needs, different types of welding overlays can be employed. In some cases, H.V.O.F. technologies are also used to extend the life of the screws.