The Draper Sds+ Series Drill Bits Are Tough And Precise. Made From An Alloy-Steel With A High-Grade Tungsten Carbide Tip For Extra-Long Life. The Double Flute Design Ensures Accuracy And Clean Holes. For Use On Concrete Masonry Brick Stone Marble Granite And Blocks. Compatible With Drills With An Sds Plus Chuck.PTDDRPDIR13883