Irwin Turbomax Drill Bit Self-centering jet point Revolutionary tip design stays sharper longer and drills up to 28% faster than other leading drill bitsHigh performance metal drilling for portable drill users, works well on curved surfacesBit is constructed of M-1 high speed steel for the best combination of strength, heat resistance and wear resistance1/4 in. diameter, 2-3/4 in. twist length, 4 in. overall lengthThree flatted shank on 3/16 in. and above for better chuck grip4 in. overall length2-3/4 in. flute length1/4 in. size drill bit