These screw conveyors are designed for conveying or dosing powders and granules. The advantage of these machines are their low maintenance requirements and low energy consumption. As they are non-standard components, they respond to a wide range of requirements and can be built of carbon steel or AISI 304 stainless steel. Diameters are determined by product quantity to be conveyed and usually range from 60 mm to 350 mm. The dosing screw is built with a single or twin screw of various spiral shapes and a direct or indirect motor drive. It is usually controlled by an inverter for more precise dosing and equipped with an on-off valve.