joint schematically indicated by 17 by the free tip 16 u2032 respectively penetrating deeply into the surrounding material particularly as a function of the material in which the bore hole 2 has been formed the safe anchorage of the widenable expansion elements 3 can be realized through a rearward movement of the foremost portion by screwing the anchor rod 4 in the sense of arrow 11 in the stop element which is stationarily fixed within the bore hole 2 in the modified embodiment represented in fig2 a plurality of widenable expansion elements 3 are fixed at different distances from the tip of the expansion anchor 1 in addition to the different distances of the widenable expansion elements 3 from the front portion 12 of the expansion anchor it is apparent in particular from fig3 that the expansion elements arranged in different radial planes also are arranged in a mutually offset relationship wherein in fig3 the expansion elements that are located closer to the tip which are each denoted by 3 u2032 in the widened state in fig2 in the system of coordinates chosen in fig3 are arranged at 0 u00b0 90 u00b0 180 u00b0 as well as 270 u00b0 while the widenable expansion elements that are located at a larger distance from the tip 12 which are denoted by 3 u2033 in fig2 are each arranged between elements 3 u2032 in the illustration according to fig2 the widenable expansion elements 3 u2032 and 3 u2033 which are illustrated.