Abstract: A tool for positioning a tapered anchor bolt assembly with its part initially oriented in a hole in a concrete wall which has been undercut to provide a conical hole portion, and for setting the anchor bolt by rigidly holding its cone properly positioned opposite the conical portion of the hole while impact-driving its sleeve inwardly of the hole to expand it over the anchor cone and fill the conical undercut portion of the hole to set the anchor therein, the tool having mutually interfering parts which limit the distance that the sleeve can be driven inwardly with respect to the cone so as to limit the driving effect of impact applied to the tool.