Abstract: An expansion sleeve for securing fastening elements, such as screws, into a wall, comprises a substantially cylindrical sleeve having an insertion end with a front portion adjacent said insertion end with an exterior surface tapering inwardly toward this end and with a plurality of outwardly extending sawtooth projections extending along the longitudinal length thereof adjacent this end. The expandable plug has a closed neck adjacent the opposite end and it includes at least one longitudinal slot and preferably one on each diametrical side extending along a substantial portion of its length from the insertion end to the solid cylindrical sleeve portion. A thickening strip extends longitudinally along preferably each diametric side on sides opposite to the slot sides and they are also provided with a series of longitudinally spaced sawtooth projections.