Tire mould and tread made by this mould

The mold to shape tire tread strips, with a tread surface (15), has at least one axial cavity opening from a wall. The cavity is molded by a finger (54) with a contour (154) which forms two rubber flows around it to a junction surface (34). The line of the junction surface has a mean length, at right angles to the mold surface (16) and in an axial direction, is longer than the minimal distance (24) between the cavity and the mold surface. The finger surface can have parallel and axial ribs (91) and grooves (92).