Enhanced strength screw-type masonry anchor

摘要

An enhanced strength screw-type, self-tapping masonry anchor for fastening a fixture or other attachment to masonry (11) in which a hole (10) is drilled to receive the anchor. The anchor is provided with a shank (13) having a root section (13R) surrounded by at least one helical male cutting thread (14;15) whose crest diameter ex-ceeds the diameter of the hole whereby when the anchor is screwed into the hole, the cutting thread then cuts a female thread in the bank (10B) of the hole to mechanically retain the anchor therein to impart to the anchor a holding power that resists axial pull-out forces. Formed on the root in the helical land between successive convolutions of the thread is a ridge (16) that is raised above the root to define a compacting zone (z) between the ridge and the bank of the hole. Particulate debris produced by the cutting action is discharged into the land and forced into the compacting zone to create a dense mass that wedges the anchor in the hole and thereby enhances the holding power of the anchor.