The invention relates to an anchor for friable materials, comprising a piercing end (3), at the other end, a bearing flange (4) with means (4') of collaboration with a tool for turning the anchor, and an anchoring screw thread (8). The anchor is characterized in that it comprises, between the bearing flange (4) and the piercing end (3), a plurality of struts (7a, 7b, 7c, 7d) for transmitting a turning torque, about which struts the screw thread (8) runs. By virtue of the invention, material is saved in the body of the anchor, the struts (7a, 7b, 7c, 7d) correctly transmitting torque without the need to overengineer the screw thread (8).