Drill bit shank Drill bit shank The shank is the end of a drill bit grasped by the chuck of a drill. The cutting edges of the drill bit contact the workpiece, and are connected via the shaft with the shank, which fits into the chuck. In many cases a general-purpose arrangement is used, such as a bit with cylindrical shaft and shank in a three-jaw chuck which grips a cylindrical shank tightly. Different shank and chuck combination can deliver improved performance, such as allowing higher torque, greater centering accuracy, or moving the bit, but not the chuck, with a hammer action. This
Drill bit sizes are named for their use in screw machines. Their shorter flute length and shorter overall length compared to a standard jobber bit results in a more rigid drill bit, reducing deflection and breakage. They are rarely available in retail hardware stores or home centers. Jobber-length drills are the most commonly found type of drill. The length of the flutes is between 9 and 14 times the diameter of the drill, depending on the drill size. So a diameter drill will be able to drill a hole deep, since it is 9 times the diameter in length. A diameter drill can