Drills are end cutting tools used to produce holes when rapid removal of material is desired. Use the shortest drill available for accurate hole location and minimum runout. Twist drills are generally effective in holes up to 3 tool diameters deep. Peck cycles should be used for deeper holes to achieve better chip evacuation. Die drills are excellent in hardened steel 35 to 65 Rockwell C and will cut without annealing the workpiece.