The reduction of the production faults and the increase of the production efficiency of the ring spinning machines is considered the ultimate goal of the yarns producers. In spite of the huge development of this industry, there are still some unsolved problems that the designers of the ring spinning machines are hoping to solve. One of these problems is to design a draughting device that reduces the breakages of threads that occur in the first draughting pair, i.e. in the rubber pressure roller with the front metallic cylinder, where there are high speed and high pressure on the fibres passing between the rubber roller and the grooved metallic cylinder. The breakages of the threads occur because of these sharp metallic grooves. The results of theoretical and experimental studies performed in this research has shown that encrusting the grooved areas of the metallic cylinder with a layer of rubber can reduce the breakages in the fibres and the spun yarns, and greatly improve the physical properties of these yarns.