Product Description Compatible with all ½” three jaw hammer-drill chucks, the Hammer-Drill Bit is specifically designed to reduce the possibility of it spinning in the chuck during heavy torsional loads. Utilizing an innovative flute geometry, the self-centering bit provides superior dust and debris removal. From the Manufacturer Milwaukee's 3-Flat Secure-Grip Hammer-Drill Bits provide superiority in regards to quality, performance and longevity of life. The 3-Flat Secure-Grip shank is designed to fit in all 1/2 in. three jaw hammer-drill chucks and reduces the possibility of the bit spinning in the chuck during heavy torsional loads. The bits drill faster and last longer than other hammer-drill bits on the market due to their reinforced flute geometry and carbide tip design. Milwaukee's offering has a range of diameters from 1/8 in. to 1 in. with lengths up to 18 in. Two per package.