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 similar ...

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, but that does not have to be straight. Intuitively, a curve may be thought of as the trace left by a moving point. This is the definition that ...

d in

compression Compression may refer to: Physical science *Compression (physics), size reduction due to forces *Compression member, a structural element such as a column *Compressibility, susceptibility to compression * Gas compression *Compression ratio, of a ...

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 ...

, rigid, and load-bearing in

tension Tension may refer to: Science * Psychological stress * Tension (physics), a force related to the stretching of an object (the opposite of compression) * Tension (geology), a stress which stretches rocks in two opposite directions * Voltage or el ...

. 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 A bicycle lock is a security device used to deter bicycle theft, either by simply locking one of the wheels or by fastening the bicycle to a fixed object, e.g., a bike rack. Quick-release levers, as used on some bicycle wheels and seatpost faste ...

, 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 mathematical space (or object) is informally defined as the minimum number of coordinates needed to specify any point within it. Thus, a line has a dimension of one (1D) because only one coor ...

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 roller chain, chain, Caterpillar track, track or other perforated or indented material. The name 'sprocket' applies generally to any wheel upon which radial ...

s of the machine, and are flexible in only one dimension. They are known as

roller chain Roller chain or bush roller chain is the type of chain drive most commonly used for transmission of mechanical power on many kinds of domestic, industrial and agricultural machinery, including conveyors, wire- and tube-drawing machines, pri ...

s, though there are also non-roller chains such as block chains. Two distinct chains can be connected using a quick link,

carabiner A carabiner or karabiner () is a specialized type of shackle, a metal loop with a spring-loaded gate used to quickly and reversibly connect components, most notably in safety-critical systems. The word is a shortened form of ''Karabinerhaken'' ...

, shackle, or

clevis A clevis fastener is a two-piece fastener system consisting of a ''clevis'' and a ''clevis pin head''. The clevis is a U-shaped piece that has holes at the end of the prongs to accept the clevis pin. The clevis pin is similar to a bolt, but is ...

. Load can be transferred from a chain to another object by a

chain stopper 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 in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A ...

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, cen ...

, type of body jewelry worn around the waist *

Jewelry chain Fine metal chains are used in jewellery to encircle parts of the body, namely the neck, wrists and ankles, and they also serve as points to hang decorative charms and pendants. Unlike industrial or chains for other purposes, jewellery chains or '' ...

, 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 C ...

, 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 t ...

, 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 du ...

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

Power transfer

Bicycle chain A bicycle chain is a roller chain that transfers power from the pedals to the drive-wheel of a bicycle, thus propelling it. Most bicycle chains are made from plain carbon or alloy steel, but some are nickel-plated to prevent rust, or simpl ...

, transfers power from the pedals to the drive-wheel of a bicycle, thus propelling it. An application of roller chain. * Chain drive, the main feature that differentiated the safety bicycle *

Chain gun A chain gun is a type of autocannon or machine gun that uses an external source of power to cycle the weapon's action, rather than diverting excess energy from the cartridges' propellant as in a typical automatic firearm, and does so via a cont ...

, 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 The chain pump is type of a water pump in which several circular discs are positioned on an endless chain. One part of the chain dips into the water, and the chain runs through a tube, slightly bigger than the diameter of the discs. As the chain is ...

, 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, pru ...

, portable mechanical, motorized saw using a cutting chain to saw wood *

Timing chain In a piston engine, either a timing belt (also called a ''cambelt'') or timing chain or set of timing gears is used to synchronize the rotation of the crankshaft and the camshaft. This synchronisation ensures that the engine's valves open and cl ...

, 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 c ...

, typically with a 2:1 speed reduction.

Security and restraint

Ball and chain A ball and chain is a physical restraint device historically applied to prisoners, primarily in the British Empire and its former colonies, from the 17th century until as late as the mid-20th century. A type of shackle, the ball and chain is ...

, 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 The term significant other (SO) has different uses in psychology and in colloquial language. Colloquially, "significant other" is used as a gender-neutral term for a person's partner in an intimate relationship without disclosing or presuming ...

(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 A bicycle lock is a security device used to deter bicycle theft, either by simply locking one of the wheels or by fastening the bicycle to a fixed object, e.g., a bike rack. Quick-release levers, as used on some bicycle wheels and seatpost faste ...

(or bicycle chain), lockable chain * Chain boom, 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 Chain mail (properly called mail or maille but usually called chain mail or chainmail) is a type of armour consisting of small metal rings linked together in a pattern to form a mesh. It was in common military use between the 3rd century BC and ...

, 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: Commo ...

, 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 * 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, the cuffs are held together by a short chain

Traction, pulling and lifting

* Anchor#Anchoring gear, 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 type of river craft that used a steel chain laid along the riverbed for its propulsion * Chain-linked Lewis, Chain-linked lewis, a self-locking lifting device particularly for stone using a chain link as a pivot * Curb chain, used on curb bits when riding a horse * High-tensile chain (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, an electrical switch operated by a ball chain ** Toilet, 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 type of chain that only bends in one direction, allowing it to operate under compression * Snow chains, used to improve traction in snow

Weapons

, 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, Chain shot, a type of ammunition for a cannon, used to inflict damage to the rigging of a sail vessel in naval warfare * Chain weapon, 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 baskets. * Chains can be used as a percussion instrument for special effects, such as in Arnold Schoenberg, Arnold Schönberg's ''Gurre-Lieder'' and Leoš Janáček's ''From the House of the Dead''. * Keychain, a small chain that connects a small item to a keyring * Chain sinnet, 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, 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. * 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, 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, due to the use for a mechanical restriction of the liberty of a human or animal. Chains can also symbolize interconnectivity or interdependence. Unicode, in versions 6.x, contains the , which may show chain link(s). It may also denote a hyperlink.

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 Chains, Mechanical power control Mechanical power transmission Jewellery Nautical terminology