Abstract: A ball anchor dowel, arranged to be inserted into and expanded into anchoring contact with a bore hole, is made up of an axially extending shank having a frusto-conical head at its leading end which is inserted first into the bore hole. The trailing end of the shank is threaded. A sleeve formed of a deformable material laterally encloses the shank and for a portion of its length forms a cavity between its inner surface and the shank. The cavity is filled with balls formed of a hard material and it is closed at its ends. By drawing the frusto-conical head rearwardly into the sleeve, the balls deform the sleeve outwardly into anchoring contact with the bore hole.