The Simpson Strong-Tie SDS-Plus Shank MDPL08718Q Drill Bit 7/8” x 18” with Quad Head4x offers contractor-grade quality for use in commercial construction. This high-volume double-helix designed bit has many enhanced features including its chromium-nickel-molybdenum steel alloy body to improve the ease of use, hammering quality and overall efficiency. Installers appreciate the centering tip for easy spot drilling, along with the uniformly brazed carbide inserts resulting in extended bit life.