Abstract: An insert for installation in a hole therefor in parent material comprises a ferrule which is longitudinally serrated externally so as to provide cutting teeth at its leading end and initially has a thin section connection at the leading end co-axially with a smaller diameter end of a body member of exterior taper form whereby on the body member being positioned for end location by its larger diameter end in a hole therefor and axial force is applied to the free other end of the ferrule, the thin section connection is first broken and the ferrule is then axially driven over the exterior taper form of the body member and expanded thereby to cause the cutting teeth at the leading end of the ferrule to shear material from the wall of the hole to a corresponding taper form and so lock the ferrule and body member in the hole against axial pull out.