The coupling comprises an assembly of axially clamped lamellae (5) at least one of which is surface-treated or surface-formed on one or both sides in order to increase the frictional torque with constant surface pressure and a given number of screws (7). The surface treatment may be carried out by abrasive blasting (using glass splinters or beads, sand or metal shot), rolling, corrugating or stamping and may be applied only to part of the area of a lamella.
