IRWIN® Straight Shank Carbide Tip Installer Bits feature an Tungsten carbide tip for extended life when drilling in brick, block and mortar joints. These bits are made with a hole in the flute for easy wire pulling through walls, ceilings and floors. They have a 3-flatted shank to prevent slipping in drill chucks and the shank also includes a hole for wire pulling. Plus, they are made from premium high carbon steel for extended drilling life in tough materials.