A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a

rope A rope is a group of yarns, plies, fibres, or strands that are twisted or braided together into a larger and stronger form. Ropes have tensile strength and so can be used for dragging and lifting. Rope is thicker and stronger than similarly ...

in that it is flexible and

curve In mathematics, a curve (also called a curved line in older texts) is an object similar to a line (geometry), line, but that does not have to be Linearity, straight. Intuitively, a curve may be thought of as the trace left by a moving point (ge ...

d in compression but

linear Linearity is the property of a mathematical relationship (''function'') that can be graphically represented as a straight line. Linearity is closely related to '' proportionality''. Examples in physics include rectilinear motion, the linear r ...

, rigid, and load-bearing in tension. A chain may consist of two or more links. Chains can be classified by their design, which can be dictated by their use: * Those designed for lifting, such as when used with a hoist; for pulling; or for securing, such as with a bicycle lock, have links that are

torus In geometry, a torus (plural tori, colloquially donut or doughnut) is a surface of revolution generated by revolving a circle in three-dimensional space about an axis that is coplanar with the circle. If the axis of revolution does not tou ...

shaped, which make the chain flexible in two

dimension In physics and mathematics, the dimension of a Space (mathematics), mathematical space (or object) is informally defined as the minimum number of coordinates needed to specify any Point (geometry), point within it. Thus, a Line (geometry), lin ...

s (the fixed third dimension being a chain's length). Small chains serving as

jewellery Jewellery ( UK) or jewelry (U.S.) consists of decorative items worn for personal adornment, such as brooches, rings, necklaces, earrings, pendants, bracelets, and cufflinks. Jewellery may be attached to the body or the clothes. From a wester ...

are a mostly decorative analogue of such types. * Those designed for transferring power in machines have links designed to mesh with the teeth of the

sprocket A sprocket, sprocket-wheel or chainwheel is a profiled wheel with teeth that mesh with a chain, track or other perforated or indented material. The name 'sprocket' applies generally to any wheel upon which radial projections engage a chain passi ...

s of the machine, and are flexible in only one dimension. They are known as roller chains, though there are also non-roller chains such as block chains. Two distinct chains can be connected using a quick link, carabiner,

shackle A shackle (or shacklebolt), also known as a gyve, is a U-shaped piece of metal secured with a clevis pin or bolt across the opening, or a hinged metal loop secured with a quick-release locking pin mechanism. The term also applies to handcuffs ...

, or clevis. Load can be transferred from a chain to another object by a chain stopper.

Uses for chain

Uses for chain include:

Decoration

Belly chain Belly may refer to: Anatomy * The abdomen, the part of the body between the pelvis and the thorax; or the stomach ** A beer belly, an overhang of fat above the waist, presumed to be caused by regular beer drinking ** Belly dance * The fleshy, cent ...

, type of body jewelry worn around the waist * Jewelry chain, many necklaces and bracelets are made out of small chains of gold and silver *

Chain of office A livery collar or chain of office is a collar or heavy chain, usually of gold, worn as insignia of office or a mark of fealty or other association in Europe from the Middle Ages onwards. One of the oldest and best-known livery collars is the Col ...

, collar or heavy gold chain worn as insignia of office or a mark of fealty in medieval Europe and the United Kingdom * Decorating clothing, some people wear wallets with chains connected to their belts, or pants decorated with chains *

Omega chain An omega chain or omega necklace is a pseudo-chain made by assembling metallic plates on a wire or woven mesh. The plates give the appearance of links in a chain. The embedded wire provides the strength, so the plates can be designed to please th ...

, a pseudo-chain where the 'links' are mounted on a backing rather than being interlinked *

Tie chain A tie chain is a neckwear-controlling device. Description Similar to tie clips and tie bars, it is used to hold in place a tie to the underlying shirt front, ensuring that the tie hangs straight. This accessory is composed of two parts, a dur ...

, used to hold in place a tie to the underlying shirt front

Power transfer

* Bicycle chain, transfers power from the pedals to the drive-wheel of a bicycle, thus propelling it. An application of roller chain. *

Chain drive Chain drive is a way of transmitting mechanical power from one place to another. It is often used to convey power to the wheels of a vehicle, particularly bicycles and motorcycles. It is also used in a wide variety of machines besides vehicles. ...

, the main feature that differentiated the safety bicycle * Chain gun, type of machine gun that is driven by an external power source, sometimes connected by a chain, to actuate the mechanism rather than using recoil * Chain pumps, type of water pump where a loop of chain inset discs is passed around then through a tube submerged in liquid *

Chainsaw A chainsaw (or chain saw) is a portable gasoline-, electric-, or battery-powered saw that cuts with a set of teeth attached to a rotating chain driven along a guide bar. It is used in activities such as tree felling, limbing, bucking, pruning, ...

, portable mechanical, motorized saw using a cutting chain to saw wood * Timing chain, used to transfer rotational position from the crankshaft to the valve and ignition system on an

internal combustion engine An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combus ...

, typically with a 2:1 speed reduction.

Security and restraint

* Ball and chain, a phrase that can refer to either the actual

restraint device Physical restraint refers to means of purposely limiting or obstructing the freedom of a person's bodily movement. Basic methods Usually, binding objects such as handcuffs, legcuffs, ropes, chains, straps or straitjackets are used for ...

that was used to slow down prisoners, or a derogatory description of a person's significant other *

(or waist chain), a physical restraint worn by prisoners, consisting of a chain around the prisoner's waist, to which the prisoner's hands are chained or cuffed Prisoner in belly chain

* Bicycle lock (or bicycle chain), lockable chain *

Chain boom A boom or a chain (also boom defence, harbour chain, river chain, chain boom, boom chain or variants) is an obstacle strung across a navigable stretch of water to control or block navigation. In modern times they usually have civil uses, such as ...

, large chains used to exclude warships from harbors and rivers *

Chain link fencing A chain-link fence (also referred to as wire netting, wire-mesh fence, chain-wire fence, cyclone fence, hurricane fence, or diamond-mesh fence) is a type of woven fence usually made from galvanized or linear low-density polyethylene-coated st ...

, fencing that utilizes vertical wires that are bent in a zigzag fashion and linked to each other * Chain mail, a type of armor consisting of small metal rings linked together in a pattern to form a mesh. *

Door chain A door chain, security chain, or security door chain or chain door interviewer consists of a small chain attached to the door frame, which attaches to a track on the door for security purposes. It is a type of lock Lock(s) may refer to: Common ...

, a type of security chain on a door that makes it possible to open a door from the inside while still making it difficult for someone outside to force their way inside * Gang transport chain, a chain used to shackle two or more inmates together for transport or work outside the facility, forming a

chain gang A chain gang or road gang is a group of prisoners chained together to perform menial or physically challenging work as a form of punishment. Such punishment might include repairing buildings, building roads, or clearing land. The system was no ...

* Leg iron chains ( fetters), an alternative to handcuffs * Prisoner transport restraints, a combination which consists of a pair of handcuffs attached by a longer chain to a pair of leg irons * On chain-linked

handcuffs Handcuffs are Physical restraint, restraint devices designed to secure an individual's wrists in proximity to each other. They comprise two parts, linked together by a Link chain, chain, a hinge, or rigid bar. Each cuff has a rotating arm whi ...

, the cuffs are held together by a short chain

Traction, pulling and lifting

* Anchor cable, as used by ships and boats; in British nautical usage the component is a cable, the material is chain * Chain slings * Chain hoist , device used for lifting or lowering a load *

Chain boat A chain boat,John MacGregor (1867). ''The voyage alone in the yawl "Rob Roy": from London to Paris, and back etc.'', London: Maranda merrill, Son and Marston, pp. 97-99. chain tug or chain-ship was a type of river craft, used in the second half o ...

, a type of river craft that used a steel chain laid along the riverbed for its propulsion * Chain-linked lewis, a self-locking lifting device particularly for stone using a chain link as a pivot *

Curb chain A curb chain, or curb strap, is a piece of horse tack required for proper use on any type of curb bit. It is a flat linked chain or flat strap that runs under the chin groove of the horse, between the bit shank's purchase arms. It has a buckle ...

, used on curb bits when riding a horse *

High-tensile chain A high-tensile chain, also referred to as a transport chain, is a link chain with a high tensile strength used for drawing or securing loads. This type of chain usually consist of broad (thick/heavy) metal, oblong torus-shaped links for high str ...

(or transport chain), chain with a high tensile strength used for towing or securing loads * Jack chain, a toothed chain used to move logs * Lead shank (or stud chain), used on horses that are misbehaving *

Pull switch A pull switch, also known as pull-cord switch, or light pull, or pull chain is a switch that is actuated by means of a chain or string. An electric pull switch is attached to a toggle type switch: one pull to switch on and next pull to switch off ...

, an electrical switch operated by a ball chain ** Lavatory chain, the chain attached to the cistern of an old-fashioned W.C. in which the flushing power is obtained by a gravity feed from above-head height. Although most cisterns no longer work like that, the phrase "pull the chain" is still encountered to mean "flush the toilet". *

Rigid chain actuator A rigid chain actuator, known variously as a linear chain actuator, push-pull chain actuator, electric chain actuator or column-forming chain actuator, is a specialized mechanical linear actuator used in window operating, push-pull material handl ...

, a type of chain that only bends in one direction, allowing it to operate under compression *

Snow chains Snow chains, or tire chains, are devices fitted to the tires of vehicles to provide increased traction when driving through snow and ice. Snow chains attach to the drive wheels of a vehicle or special systems deploy chains which swing under ...

, used to improve traction in snow

Weapons

* Chain gun, type of machine gun that is driven by an external power source, sometimes connected by a chain, to actuate the mechanism rather than using recoil * Chain shot, a type of ammunition for a

cannon A cannon is a large- caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder ...

, used to inflict damage to the

rigging Rigging comprises the system of ropes, cables and chains, which support a sailing ship or sail boat's masts—''standing rigging'', including shrouds and stays—and which adjust the position of the vessel's sails and spars to which they are ...

of a sail vessel in

naval warfare Naval warfare is combat in and on the sea, the ocean, or any other battlespace involving a major body of water such as a large lake or wide river. Mankind has fought battles on the sea for more than 3,000 years. Even in the interior of large la ...

Chain weapon A chain weapon is a weapon made of one or more heavy objects attached to a chain, sometimes with a handle. The flail was one of the more common types of chain weapons associated with medieval Europe, although some flails used hinges instead of chai ...

, a medieval weapon made of one or more weights attached to a handle with a chain

Other uses

* Chains are a common component of the deflection assembly of

disc golf basket A basket is by far the most common type of target used in disc golf. It features a disc-catching basket under a deflection assembly generally made out of chain. Permanent baskets on courses are built on an anchored metal pole, but portable disc g ...

s. * Chains can be used as a

percussion instrument A percussion instrument is a musical instrument that is sounded by being struck or scraped by a beater including attached or enclosed beaters or rattles struck, scraped or rubbed by hand or struck against another similar instrument. Exc ...

for special effects, such as in Arnold Schönberg's '' Gurre-Lieder'' and Leoš Janáček's '' From the House of the Dead''. *

Keychain A keychain (also key fob or keyring) is a small ring or chain of metal to which several keys can be attached. The length of a keychain allows an item to be used more easily than if connected directly to a keyring. Some keychains allow one or bo ...

, a small chain that connects a small item to a keyring *

Chain sinnet A chain sinnet (or chain sennit) is a method of shortening a rope or other cable while in use or for storage. It is formed by making a series of simple crochet-like stitches in the line.Clifford W. Ashley, ''The Ashley Book of Knots'' (New York ...

, a method of shortening a rope or other cable while in use or for storage * Chain stitch, a sewing and embroidery technique

Types of chain

Ball chain Ball chain is a type of chain consisting of small sheet metal balls connected via short lengths of wire. The balls are hollow and have two small antipodal holes. These holes accept a short length of wire deformed on the end like a rivet so that ...

, type of chain consisting of small sheet metal balls connected via short lengths of wire * Calibrated chain, a type chain where the link lengths are within a given tolerance, so that it reliably engages with a

windlass The windlass is an apparatus for moving heavy weights. Typically, a windlass consists of a horizontal cylinder (barrel), which is rotated by the turn of a crank or belt. A winch is affixed to one or both ends, and a cable or rope is wound arou ...

. * Flat chain, form of chain used chiefly in agricultural machinery * Ladder chain, a light wire chain used with sprockets for low torque power transmission * Long link chain * O-ring chain, a specialized type of roller chain * Roller chain, the type of chain most commonly used for transmission of mechanical power on bicycles, motorcycles, and in industrial and agricultural machinery *

Self-lubricating chain Self-lubricating chains, also referred to as lube-free chains, are commonly found in both roller chain ( ANSI Standards, British Standards, and DIN Standards) and conveyor chain varieties, with specialty self-lubricating chains also available. Thes ...

, type of chain that uses a bush to continually lubricate the chain * Silent chain, a type of chain in which the links engage the sprockets similarly to gear teeth * Stud link chain, a type of chain with metal between the sides of each link, keeping the attached links in place. This helps prevent bunching when the chain is run out from a storage bin, as for use in anchoring ships. * Short link chain, a chain where the gap between attached links is small relative to thickness.

Connections

Several methods are available to connect chain ends to each other or to other objects, and to apply a load to a chain away from the ends. These methods are usually specific to the type of chain, and must be of the correct size.

Invention

The metal link chain has been in use since at least 225 BC.As early as 225 BC, chain was used to draw a bucket of water up from a well. This very early bucket chain was composed of connected metal rings.

Symbolism

The prevalent modern symbolism is

oppression Oppression is malicious or unjust treatment or exercise of power, often under the guise of governmental authority or cultural opprobrium. Oppression may be overt or covert, depending on how it is practiced. Oppression refers to discrimination w ...

, due to the use for a mechanical restriction of the

liberty Liberty is the ability to do as one pleases, or a right or immunity enjoyed by prescription or by grant (i.e. privilege). It is a synonym for the word freedom. In modern politics, liberty is understood as the state of being free within society fr ...

of a human or animal. Chains can also symbolize

interconnectivity In telecommunications, interconnection is the physical linking of a carrier's network with equipment or facilities not belonging to that network. The term may refer to a connection between a carrier's facilities and the equipment belonging to ...

interdependence Systems theory is the interdisciplinary study of systems, i.e. cohesive groups of interrelated, interdependent components that can be natural or human-made. Every system has causal boundaries, is influenced by its context, defined by its struc ...

Unicode Unicode, formally The Unicode Standard,The formal version reference is is an information technology Technical standard, standard for the consistent character encoding, encoding, representation, and handling of Character (computing), text expre ...

, in versions 6.x, contains the , which may show chain link(s). It may also denote a

hyperlink In computing, a hyperlink, or simply a link, is a digital reference to data that the user can follow or be guided by clicking or tapping. A hyperlink points to a whole document or to a specific element within a document. Hypertext is text wit ...

Gallery

File:Silent chain.jpg, Silent chain File:Rope chain.jpg, Rope chain File:Twisted link chain.jpg, Twisted link chain File:Wheat chain.jpg, Wheat chain File:Single-jack-chain.jpg, Single jack chain File:Double jack chain.jpg, Double jack chain File:Studlink chain link.jpg, Stud link chain File:Ladder link chain.jpg, Ladder link chain File:Foxtail chain.jpg, Foxtail chain File:Singapore chain.jpg, Singapore chain File:Rolo chain.jpg, Rolo chain File:BikeChain.png, Bike Chain

References

External links

National Association of Chain Manufacturers
NACM WELDED STEEL CHAIN SPECIFICATIONS
Chain Spec Basics
Grades and Links Explained * {{Authority control Mechanical power control Mechanical power transmission Jewellery Nautical terminology