Abstract: A device for anchoring in and/or reinforcing hard materials, such as stone, concrete and the like, is described. The device consists of a continuous body, made in one piece, designed for insertion axially into a mounting hole in said materials and which has, transverse to its axis, expansible gripping surfaces or points arranged so as to, when expanded, bear against and engage the sides of the hole for anchoring the device into the hole. In order to achieve the said expansion of the gripping surfaces or points, the shell is provided with, firstly, one or more axial rows (1,2) of pressure absorbing braces (3) between the expansible gripping surfaces or points, which braces (3) are, at least upon insertion of the device in the hole, inclined to the axial direction of the device with their first ends (6) axially displaced in relation to their second ends (7) in a direction towards the insertion end (5) of the device.