Powers' Tapper+ 3/16" X 4" Phillips Flat Head Concrete Screw Anchors (100/BX) 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 also feature a gimlet point for self-drilling into wood base materials without pre-drilling.