A crocodile clip or alligator clip is a

plier Pliers are a hand tool used to hold objects firmly, possibly developed from tongs used to handle hot metal in Bronze Age Europe. They are also useful for bending and physically compressing a wide range of materials. Generally, pliers consist ...

-like

spring Spring(s) may refer to: Common uses * Spring (season) Spring, also known as springtime, is one of the four temperate seasons, succeeding winter and preceding summer. There are various technical definitions of spring, but local usage of ...

-tensioned metal clip with elongated, serrated jaws that is used for creating a temporary

electrical connection Components of an electrical circuit are electrically connected if an electric current can run between them through an electrical conductor. An electrical connector is an electromechanical device used to create an electrical connection between ...

. This simple mechanical device gets its name from the resemblance of its serrated jaws to the toothed jaws of a

crocodile Crocodiles (family (biology), family Crocodylidae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to inclu ...

alligator An alligator is a large reptile in the Crocodilia order in the genus ''Alligator'' of the family Alligatoridae. The two extant species are the American alligator (''A. mississippiensis'') and the Chinese alligator (''A. sinensis''). Additiona ...

. It is used to clamp and grab onto a bare

electrical cable An electrical cable is an assembly of one or more wires running side by side or bundled, which is used to carry electric current. One or more electrical cables and their corresponding connectors may be formed into a ''cable assembly'', which ...

to an

lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...

on a

battery Battery most often refers to: * Electric battery, a device that provides electrical power * Battery (crime), a crime involving unlawful physical contact Battery may also refer to: Energy source *Automotive battery, a device to provide power t ...

or some other electrical component. Functioning much like a spring-loaded

clothespin A clothespin (US English), or clothes peg (UK English) is a fastener used to hang up clothes for drying, usually on a clothes line. Clothespins come in many different designs. Design During the 1700s laundry was hung on bushes, limbs or lin ...

, the clip's tapered, serrated jaws are forced together by a

to grip an object. When manufactured for electronics testing and evaluation, one jaw of the clip is typically permanently crimped or soldered to a wire, or is bent to form the inner tubular contact of a ~ female

banana jack A banana connector (commonly banana plug for the gender of connectors and fasteners, male, banana socket or banana jack for the gender of connectors and fasteners, female) is a single-wire (one electrical conductor, conductor) electrical connec ...

, enabling quick non-permanent connection between a circuit under test and laboratory equipment or to another

electrical circuit An electrical network is an interconnection of electrical components (e.g., batteries, resistors, inductors, capacitors, switches, transistors) or a model of such an interconnection, consisting of electrical elements (e.g., voltage sources, ...

. The clip is typically covered by a plastic shroud or "boot" to prevent accidental short-circuits. Small versions, ranging in size from in length, are used in electrical

laboratory A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratory services are provided in a variety of settings: physicia ...

work. Large versions of these clips, called automotive clips or battery clamps, are made of solid

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

for low

electrical resistance The electrical resistance of an object is a measure of its opposition to the flow of electric current. Its reciprocal quantity is , measuring the ease with which an electric current passes. Electrical resistance shares some conceptual parallels ...

, and are used with thick insulated copper cables to make connections between automobile batteries. These

jumper cable Jumper cables are electric cables to connect two rail or road vehicles. Rail Jumper cables are between the locomotive, the railroad cars and the cab car or the driving van trailer on push-pull trains for multiple-unit train control and the tr ...

s (a.k.a. 'jump leads') are capable of delivering hundreds of Amperes of current needed to directly power an automobile starter motor, or to transfer energy from a charged

lead–acid battery The lead–acid battery is a type of rechargeable battery first invented in 1859 by French physicist Gaston Planté. It is the first type of rechargeable battery ever created. Compared to modern rechargeable batteries, lead–acid batteries have ...

to a discharged one.

Specifications

The United States Defense Logistics Agency specifies several types of electrical clips in Commercial Item Description (CID) A-A-59466. In this CID document, crocodile clips are designated type CC, alligator clips are designated types TCx, and other types of electrical clips have various other, unique designations.

Other uses

* Dentistry: crocodile clips are often used on the ends of a cord in dental offices to attach a protective bib over the patient's clothing. * Laboratory: crocodile clips are frequently used to quickly and cheaply assemble or modify experimental circuits. They are useful for connecting components to wires. * Education: like their laboratory use, crocodile clips are sometimes used with batteries, small lightbulbs and other small electrical devices in schools to teach students about electricity. * Fencing: crocodile clips are used in

fencing Fencing is a group of three related combat sports. The three disciplines in modern fencing are the foil, the épée, and the sabre (also ''saber''); winning points are made through the weapon's contact with an opponent. A fourth discipline, s ...

to connect to participants' lamé vests to touch-detection systems. * Hobby: crocodile clips can be used as miniature clamps to hold parts together for

gluing Adhesive, also known as glue, cement, mucilage, or paste, is any non-metallic substance applied to one or both surfaces of two separate items that binds them together and resists their separation. The use of adhesives offers certain advant ...

soldering Soldering (; ) is a process in which two or more items are joined by melting and putting a filler metal (solder) into the joint, the filler metal having a lower melting point than the adjoining metal. Unlike welding, soldering does not involv ...

(e.g., Helping hands tool). * Camping: crocodile clips may be designed to attach a rope to a tarp or other sheet of material. (While this serves the same purpose as a grommet, it may lead to premature wear at the point of attachment.) * Drug use: as a

roach clip A joint (), also commonly referred to as a "doobie" or "doob", is a rolled cannabis cigarette. Unlike commercial tobacco cigarettes, the user ordinarily hand-rolls joints with rolling papers, though in some cases they are machine-rolled ...

for holding burning

cannabis ''Cannabis'' () is a genus of flowering plants in the family Cannabaceae. The number of species within the genus is disputed. Three species may be recognized: ''Cannabis sativa'', '' C. indica'', and '' C. ruderalis''. Alternatively ...

to avoid burning fingers. * Erotic use: as a clamp upon one's nipples for sexual gratification. See

nipple clamp A nipple clamp is a type of sex toy that is applied to a person's nipples to pinch them. Varieties of nipple clamp include clothes-pin-style, tweezer and clover. Nipple clamps are used to cause pain in the nipples as part of certain BDSM ac ...

for more information on this usage. * Film/animation: useful for airborne scenes in possible stop-motion or holding models of any sort in mid air. * Electronics: useful as a

heat sink A heat sink (also commonly spelled heatsink) is a passive heat exchanger that transfers the heat generated by an electronic or a mechanical device to a fluid medium, often air or a liquid coolant, where it is dissipated away from the device, th ...

while soldering heat-sensitive devices.

Kelvin clip

Kelvin clip Four-terminal sensing (4T sensing), 4-wire sensing, or 4-point probes method is an electrical impedance measuring technique that uses separate pairs of current-carrying and voltage-sensing electrodes to make more accurate measurements than the si ...

is a special form of crocodile clip. The jaws of a Kelvin clip are insulated from each other, allowing two isolated wires to connect to a single test point. This enables 4-wire measurement of circuits with very low resistances.

References

External links

{{commons category, Alligator clips ;Historical catalogs
''Battery / Radio / Connecting Clips''
- 1929 Allied Radio catalog, page 46
''Alligator / Battery / Spring Clips''
- 1932 Lafayette catalog, page 76 / 81
''Alligator / Battery / Test Clips''
- 1939 Allied Radio catalog, page 38 / 137 / 138
''Alligator / Crocodile Clips''
- 1940 Allied Radio catalog, page 181 / 182

- 1940 Radio Shack catalog, page 85 ;Historical patents
U.S. Patent 55524 ''Test Clip''
- filed in 1919 by R.S. Mueller
U.S. Patent 1521903 ''Connection Clip''
- filed in 1921 by R.S. Mueller
U.S. Patent 1779442 ''Electrical Connection Clip''
- filed in 1925 by R.S. Mueller
U.S. Patent 1999613A ''Connecting Clip''
- filed in 1934 by R.S. Mueller
U.S. Patent 6623314B1 ''Kelvin clamp for electrically coupling to a battery contact''
- filed in 2002 by Midtronics Inc. ;Historical trademarks
''Pee-Wee''
- filed in 1925 by Mueller Electric
(current products)

''MINI-GATOR''
- filed in 1955 by Mueller Electric
(current products)
Electrical connectors ja:ワニグチクリップ