Anchor for fastening a component to a hollow or solid support material, said anchor comprising a sheath of elongate shape that is intended to be introduced into a hole in said support material, said anchor also comprising a bearing mechanism for bearing against an external face of said support material, situated at a first longitudinal end of said sheath, and a piston member situated at a second, opposite longitudinal end of said sheath and configured to engage with a screw intended to be introduced into said sheath, characterized in that said piston member is configured to be moved longitudinally inside said sheath by said screw.