DEWALT Carbide Tipped Hole Saw Pilot Drills Are Designed For Tool-Free Use With The DEWALT RAPID LOAD Hole Saw Accessory System And Are Compatible With All Non-Quick Change Arbors. Carbide Tip Design Is Optimized For Extreme Durability Drilling Through Hard Materials Like Concrete Block And Fiber Cement. Not Compatible with proprietary Arbor Systems Not Using Standard 1/4in Shank Pilot Drills