An anchor includes a rotatable anchor rod an anchor plate and an anchor nut. The screw thread in the anchor nut matches the screw thread of the anchor rod only over part of the screw thread hole. Thus the anchor nut can only be screwed some way further onto the anchor rod, and up to a predetermined torque can be used for rotating the anchor rod during placement of the anchor. As soon as the anchor rod is firmly seated in the drill hole, as a result of the action of adhesive, mortar or expansion or spreading, the anchor rod forms a through-thread in the screw thread hole when the anchor nut is rotated relative to the anchor rod, and consequently the anchor nut can finally be screwed onto the anchor rod until it affixes the anchor plate in its final position to the ground.