Milwaukee 3-Flat Secure-Grip Hammer-Drill Bits drill faster and last longer than others on the market. The 3-Flat Secure-Grip shank fits in all 1/2 In. three-jaw hammer-drill chucks and maintains unyielding bit hold with heavy torsional loads. Designed especially for conical anchor, concrete screw, nail-in and hollow wall anchor applications, the bit provides superior performance through its reinforced flute geometry and carbide tip design.