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" 3-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. Includes: 5/32", 5/16", 3/8", 3/16", 1/4" bits in 6" lengths.