Wood screw (lead) anchors are wedged into a hole and then expanded for a tight fit with the insertion of a wood screw or similar item. They are used where strength requirements are not as great as when shields are used, and are not threaded internally. Wood screw anchors can also be used in solid masonry and concrete, and are used for light, shallow hold anchoring. As it expands, the outer wall flows into any irregularities in the hole wall, enabling correct setting in imperfect holes.
