Friction clutch by means of friction material is the most common way to control power transmission. Clutch discs can widely vary according to different applications. In dry applications clutch discs can be both rigid or spring-loaded type. Coupling with the rotating part is mainly on the central hub. It can be carried out on the outside diameter by means of a toothed profile or radial wings. The friction material used on clutch plates for dry use can be moulded, woven or sintered type. Clutches for wet use which are often made by multiple discs has the advantage of lower noise and wear as well as softer couplings. In such kind of applications paper based and sintered friction materials are required. Paper based friction materials are mainly used in automotive automatic transmissions, but are also very popular in the industrial and tractor fields where are used on power shifts due to their low noise level and very low wear.