A friction part for a frictionally acting device comprising an annular friction surface which has an inner edge and an outer edge, with the friction surface having provided in it an encircling first groove which extends in zig-zag or undulating form between radially inner and radially outer deflection points, a plurality of second grooves which extend from the inner edge to the outer deflection points and a plurality of third grooves which extend from the outer edge into the encircling first groove and which open into the encircling first groove at opening-in points between the deflection points.