These 1/4 in. x 1-1/4 in. Tapper flat head concrete screw anchors are made of steel and sold as a box of 100. Tapper concrete screw anchors are manufactured for top performance in masonry-based applications and are designed to fasten objects into concrete, brick and block. The Tapper line uses a Perma-Seal climate coating for long-lasting protection against corrosion and the elements. They are an excellent alternative to expansion anchors, and the unique thread design allows a steady drive and torque reduction when installing in concrete. Use a masonry drill bit sized for the anchor to drill the hole before driving.