The Grip-Rite Phillips Flat Head Concrete Screws are built of steel for long-lasting durability and are 3-3/4 inches long and have a wire diameter of 3/16 inches. The screws come in a 100-pack for your convenience. Use these screws for a variety of projects like fixing sill plates, electrical equipment, and many other fixtures to masonry. These are ideal for fastening wood and concrete materials.