The Powers Tapper+ 3/16" X 3-1/4" Concrete Screw Anchors w/ Phillips Flat Heads (100/BX) (2748SD) are for light to medium duty applications in concrete, masonry block, brick, and wood base materials. They are fast and easy to install and provide a neat, finished appearance. These Tapper+ screw anchors are engineered with matched tolerance drill bits and installation tools designed to meet the needs of the user and also provide optimum performance. They feature a gimlet point for self-drilling into wood base materials without pre-drilling.