Concrete screws, also known as masonry screws or anchor screws, are screws used to secure materials to concrete, brick or block. Made for light duty fastening, concrete screws are quickly becoming a popular way to anchor materials to masonry. These screws are hardened and coated in a blue coating to protect them, which is part of the protective coating which extends the corrosion and rust resistance of the screw, making them suitable for exterior and long-lasting applications. Due to this unusual color these screws have also become known as blue screws. One of the greatest benefits of concrete masonry screws is that they can be easily removed if necessary unlike expanding masonry anchors. Concrete screws come in 3/16" and 1/4" diameters. The 3/16" screws are considered good for general use applications and where the concrete is soft. If the screws have a problem drilling into the material or the load is heavy, 1/4" concrete screws will be a better fit. As a rule of thumb, the harder the material is the stronger the hold will be. They are hardened and tap their own threads during installation. Anchor screws are mainly used to hold metal or wood to concrete. Concrete screws are available in both Phillips flat head and Hex Washer head varieties. The Phillips version is often used when a flush head is needed but the hex washer head is easier to drive. Anchor screws need to be a minimum of 1" embedded in the masonry material to be considered properly installed. Hex Slotted Washer Head 1/4 x 3-1/4 Qty-100 Tapcon masonry anchor screw fasteners.