Drill Chuck and Spare Key

Drill chucks are devices used to hold a drill or other cutting tools on a spindle. They are available in keyed, keyless or hybrid systems, allowing for quick changes of a drill bit. Diagram of a Drill Chuck. Key Styles: Keyed chucks are engineered to either loosen or tighten the hold on a tool by using a key.A chuck is a specialized type of clamp used to hold an object with radial symmetry, especially a cylinder. In a drill, a mill and a transmission, a chuck holds the rotating tool; in a lathe, it holds the rotating workpiece.10mm (3/8 inch) is the first standard size. These have a smaller chuck and are less powerful than those with a bigger chuck. To make up for this, they are usually more cheap than other drills. 13mm, or 1/2 inch, is the next common size. These are often larger, more professional drills.Loosen the chuck (the black circular section on the front of the drill) by twisting it counterclockwise to widen the diameter of the jaws that clamp onto the drill bit. Insert the shank (smooth part) of the drill bit into the jaws, and re-tighten the chuck until the drill bit is secured.