Abstract: A stabilizer is disclosed that can be mounted on the outside of the drill string. It includes a tubular body having a bore to receive the drill string to allow the body to be moved over the drill string to the desired location. A portion of the bore has a locking taper in which is located a plurality of slip fingers. A sleeve member is connected to the body by threads and is in engagement with the slip fingers. Relative rotation of the sleeve and the body will cause the sleeve to force the slip fingers along the tapered bore of the body and into frictional engagement with the outside surface of the drill string to hold the stabilizer in the desired location thereon.