Chuck (engineering)

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. Chucks commonly use jaws to hold the tool or workpiece. The jaws are typically arranged in a radially symmetrical pattern like the points of a star. Jawed chucks may require a wrench-like device called a chuck key to be tightened or loosened, but other jawed chucks may be tightened or loosened by hand force alone, offering convenience at the expense of gripping force. Chucks on some lathes have jaws that move independently, allowing them to hold irregularly shaped objects. More complex designs might include specially shaped jaws, greater numbers of jaws, or quick-release mechanisms. Instead of jaws, a chuck may use magnetism, vacuum, or collets, which are flexible collars or sleeves that fit closely around the tool or workpiece and grip it when squeezed.

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. Chucks commonly use jaws to hold the tool or workpiece. The jaws are typically arranged in a radially symmetrical pattern like the points of a star. Jawed chucks may require a wrench-like device called a chuck key to be tightened or loosened, but other jawed chucks may be tightened or loosened by hand force alone, offering convenience at the expense of gripping force. Chucks on some lathes have jaws that move independently, allowing them to hold irregularly shaped objects. More complex designs might include specially shaped jaws, greater numbers of jaws, or quick-release mechanisms. Instead of jaws, a chuck may use magnetism, vacuum, or collets, which are flexible collars or sleeves that fit closely around the tool or workpiece and grip it when squeezed. ===== Drill chuck===== is applied. Bottom: the widely used keyed type of drill chuck with its key. The arbor is shown separately to the right. These chucks require a toothed key to provide the necessary torque to tighten and loosen the jaws. When the key is turned its teeth mate with teeth on the chuck, turning an internal screw which in turn moves the threaded jaws in or out along a tapered surface. The taper allows the jaws to clamp drill shanks of a range of diameters. The end view shows the three small jaws that slide within the body.]] A drill chuck is a specialised self-centering, three-jaw chuck, usually with capacity of or less, and rarely greater than , used to hold drill bits or other rotary tools. This type of chuck is used on tools ranging from professional equipment to inexpensive hand and power drills for domestic use. Some high-precision chucks use ball thrust bearings to reduce friction in the closing mechanism and maximize drilling torque. One brand name for this type of chuck, which is often genericized in colloquial use although not in catalogs, is Super Chuck. A pin chuck is a specialized chuck designed to hold small drills (less than in diameter) that could not be held securely in a normal drill chuck. The drill is inserted into the pin chuck and tightened; the pin chuck has a shaft which is then inserted into the larger drill chuck to hold the drill securely. Pin chucks are also used with high-speed rotary tools other than drills, such as die grinders and jig grinders.

Text derived from https://en.wikipedia.org/w/index.php?oldid=1373605314 under CC BY-SA 4.0; modifications have been made.