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Wire and Cable Terminology and Definitions


Abrasion Resistance

Abrasion resistance is the ability of a wire, cable, or material to resist surface wear.

Accelerated Aging

In an accelerated aging test, voltage, temperature, etc., are increased above normal operating values to obtain observable deterioration in a relatively short period of time.

Aerial Cable

Aerial cable is suspended in the air on poles or other overhead structures.


An alloy is a mixed metal formed by combining two or more different metals to obtain desirable properties.


Aluminum sheathed cable (ALS) contains insulated conductors enclosed in a continuous closely fitting aluminum shield.

Alternating Current (AC)

An alternating electric current continually reverses its direction. It is expressed in cycles per second, in units called hertz (or Hz).

Ambient Temperature

Ambient temperature refers to the temperature of a medium surrounding an object.

American Wire Gauge (AWG)

AWG is a standard system for designating wire diameter primarily used in the United States.


Also called "current carrying capacity," ampacity is the maximum current an insulated wire or cable can safely carry without exceeding either the insulation or jacket material limitations.

Ampere (Amp)

Ampere is a unit of current. One ampere is the current flowing through one ohm of resistance at a one-volt potential.


Analog refers to the representation of data by continuously variable quantities.

Annealed Wire

Annealed wire has been heated and slowly cooled after the final drawdown to remove the effects of cold working.


The ANSI abbreviation stands for American National Standards Institute.


An antioxidant is a substance that prevents or slows down the oxidation of material exposed to heat.


Wire and cable armor refers to a braid or wrapping of sheet metal, usually steel or aluminum, used for mechanical protection.


The ASA abbreviation stands for the American Standards Association, formally named ANSI.


ASCII is the abbreviation for the American Standard Code for Information Interchange.


ASME is the abbreviation for the American Society of Mechanical Engineers.


ASTM is the abbreviation for the American Society for Testing and Materials.


Attenuation is power loss in an electrical system. In cables, attenuation is generally expressed in -dB per unit length.

Audio Frequency

Audio or audible frequencies are sounds audible to the human ear in the range of 32 - 16,000 hertz (Hz).


AWG is the abbreviation for America Wire Gauge.


AWM is the designation for appliance wiring material.

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Balanced Circuit

In a balanced circuit, power is transferred symmetrically in two wires, with one wire output at a 180-degree phase difference from the other wire.

Band Marking

A band marking is a continuous circumferential band applied to a conductor at regular intervals for identification.


Bandwidth is the difference between the upper and lower limits of a given band of frequencies. It is expressed in hertz (Hz).


A baud is a unit of data transmission speed representing bits per second. 9600 baud = 9600 bits per second.


Binder is spirally served tape or thread used for holding assembled cable components in place awaiting subsequent manufacturing operations.


A bit is one binary digit.

Bit Error Rate (BER)

Bit error rate represents the discrepancy between outgoing and incoming bits transmitted between data equipment.

Bond Strength

Bond strength is the amount of adhesion between surfaces, e.g. in a cemented ribbon cable.


A braid is a fibrous metallic group of filaments interwoven in cylindrical form to cover one or more wires.

Braid Angle

A braid angle is the smaller of the two angles formed by the shielding strand and the axis of the cable being shielded.

Braid Carrier

A braid carrier is a spool or bobbin on a braider that holds one group of strands or filaments consisting of a specific number of ends. The carrier moves in a revolving motion during braiding operations.

Braid Ends

Braid ends refer to the number of strands used to make up one carrier. The strands are wound side by side on the carrier bobbin and lie parallel in the finished braid.

Breakdown Voltage

Breakdown voltage is the voltage at which the insulation between two conductors is destroyed.


The breakout is the point at which a conductor or group of conductors is separated from a multiconductor cable to complete circuits at various points along the main cable.

Building Wire

Building wire is used for lighting and power distribution, 600 volts or less, and is not typically exposed to an outdoor environment.

Bunch Stranding

Bunch stranding groups wires of the same diameter together, twisting without a predetermined pattern.

Buried Cable

Buried cable is installed directly in the ground without an underground conduit. It is also called "direct burial cable".


A byte is a group of eight binary digits.

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An electrical cable is a group of individually insulated conductors in a twisted or parallel configuration inside a common sheath.


Cabling refers to the twisting together of two or more insulated conductors to form an element.


CAD and CAM are abbreviations for Computer Aided Design and Computer Aided Manufacturing, respectively.


Capacitance is the storage of electrically separated charges between two plates having different potentials. The value depends largely on the surface area of the plates and the distance between them.

Capacitance - Direct

Direct capacitance is measured directly from conductor to conductor through a single insulating layer.

Capacitance - Mutual

Mutual capacitance is the capacitance between two wires with all other conductors, including the shield, short-circuited to ground.

Capacitive Coupling

Capacitive coupling is the electrical interaction between two conductors caused by the potential difference between them.


CATV is the acronym for Community Antenna Television.

Cellular Polyethylene

Cellular polyethylene is expanded or "foam" polyethylene consisting of individual closed cells suspended in a polyethylene medium.

Certificate of Compliance (C of C)

A certificate of compliance is typically issued by a Quality Control Department to verify the product being shipped meets the customer's specifications.

Certified Test Report (CTR)

A certified test report provides actual test data on an electrical cable. Tests are normally run by a Quality Control Department to show that the product being shipped conforms to test specifications.

Characteristic Impedance

Characteristic impedance is the resistance of an electrical line propagating along a uniform transmission line of infinite length.

Circuit Sizes

Circuit size wire refers to building wire sizes 14 through 10 AWG commonly used in circuits.

Circular Mil

Circular mil is the area of a circle one millimeter (.001 m) in diameter. This value is used in expressing a wire's cross-sectional area, which can be calculated using the formula: 7.845 x 10-7 in2


Cladding is a method of applying a metal over another metal whereby the junction of the two metals is continuously welded.

Coaxial Cable

Coaxial cable (or coax cable) consists of two cylindrical conductors with a common axis, separated by a dielectric.

Cold Flow

Cold flow is the deformation of cable insulation due to mechanical force or pressure (and not due to heat softening).

Common Axis Cabling

In multiple cable constructions, common axis cables twist all conductors around a "common axis" with two conductor groups, selected as pairs. This practice yields smaller diameter constructions than a separate axis susceptance to EMI and ESI.

Common Carrier

A common carrier is any public transmission link. Examples from among telephone landlines would be the Bell or General Telephone Systems.

Common Mode

Common mode refers to signals or noise flowing in the same direction and caused by a difference in "ground potential". To reduce the interference, ground one end of the conductor at the source, rather than both ends.

Composite Cable

A composite cable contains more than one gauge size or a variety of circuit wire types, e.g. pairs, triples, quads, coaxial, etc.


Compound is insulation or jacketing material made by mixing two or more ingredients.

Concentric Stranding

In concentric stranding, a central wire is surrounded by one or more layers of helically wound strands in a fixed round geometric arrangement.


Concentricity in a wire or cable is the measurement of the location of a conductor's center in regard to the geometric center of the surrounding insulation.


Conductance is the ability of a conductor to carry an electrical charge. It is the ratio of the current flow to the potential difference causing the flow. Conductance is the reciprocal of resistance.


Conductivity is the capability of a material to carry an electrical current. It is usually expressed as a percentage of copper's conductivity (with copper conductors having a conductivity of 100%).


A conductor is an insulated wire suitable for carrying electrical current.


Conduit is a tube or trough through which insulated wires and cables are passed.


A connector is a device used to physically and electrically join two or more conductors.

Continuous Vulcanization

Continuous vulcanization is a technique for the simultaneous extrusion and curing of elastomeric wire coating materials.

Control Cable

A control cable is a multiconductor cable made for operation in control or signal circuits.


A copolymer is any compound resulting from the polymerization of two different monomers.


Copper-clad refers to a metal like steel with a coating of copper welded to it, as distinguished from copper-plated.


A cord is a small, flexible insulated cable.


In cables, the core is the central component or assembly of components over which additional components (shield, sheath, etc.) are applied.


An electrical corona is a discharge due to the ionization of air around a conductor. This occurs when a potential gradient exceeds the critical value.

Corona Resistance

Corona resistance is a value that specifies the amount of time cable insulation can withstand a specific level of field-intensified ionization without breakdown.


Corrosion is the deterioration of a material by chemical reaction or galvanic action.


Crazing refers to the minute cracks on the surface of plastic or other materials.


With electrical wire and cable, creep is the elongation of the wire or cable that occurs with time spent under load.


Cross-linked is a term denoting intermolecular bonds between long-chain thermoplastic polymers, affected by chemical or irradiation techniques.


Cross-talk is a type of interference caused by signals from one circuit being coupled into adjacent circuits.


CRT is the abbreviation for Cathode Ray Tube, an older technology for video display terminals like computer monitors. Similar abbreviations are VDU and VDT.

Current Carrying Capacity

The current carrying capacity of wire and cable is the maximum current an insulated conductor can safely carry without exceeding its insulation and jacket temperature limitations (same as Ampacity).

Cut-Through Resistance

Cut-through resistance is the ability of a material to withstand mechanical pressure, like a sharp edge or point, without separation.


CV is the abbreviation for Continuous Vulcanization, a technique for the simultaneous extrusion and curing of elastomeric wire coating materials.

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DCE is the abbreviation for Data Communication Equipment such as a modem.

Decibel (dB)

Decibel (dB) is a common unit used to express differences in a power level. A term that expresses two power levels used to indicate gains or losses in a system.

Derating Factor

The derating factor is used to reduce the current carrying capacity of a wire when used in environments other than that for which the value was established.


Dielectric material is any insulating material between two conductors that permits electrostatic attraction and repulsion to take place across it.

Dielectric Strength

Dielectric strength is the amount of voltage an insulation can withstand before breakdown occurs. It is usually expressed as a voltage gradient (such as volts per mil).


The word digital refers to any data represented by discrete characters (i.e., digits).

Direct Current (DC)

Direct current is an electric current that flows in one direction.


DMUX is an abbreviation for demultiplex, the act of decoding a meaningful sequence like a barcode.

Double Foot

A double foot is the combined length of one linear foot of paired materials; i.e. one double foot is equal to one foot of positive.

Drain Wire

In a cable, the drain wire is an uninsulated wire in close contact with a shield to provide for easier termination of the shield to ground.


DTE is the abbreviation for Data Terminal Equipment such as monitors or printers.


Ducts are underground or overhead tubes for carrying electrical cables.


Duplex refers to two-way simultaneous data transmission, usually on a four-wire facility.

Duplex Insulated

In the thermocouple industry, duplex insulation is a combination of dissimilar metal conductors of a thermocouple wire.

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EIA is the abbreviation for Electronic Industries Association.


Elastomers are a class of long-chain polymers capable of being cross-linked to produce elastic and magnetic fields associated with the movements of electrons through conductors, e.g. polychloroprene and ethylene propylene rubber.


Electromagnetic refers to the combined electric and magnetic fields associated with the movements of electrons through conductors.

Electromotive Force (EMF)

Electromotive force can be described in terms of pressure or voltage. It is the force that causes current to flow in a circuit.


Electrostatic refers to static electricity, or electricity at rest. It is a constant-intensity electric charge.


Elongation is the fractional increase in the length of material stressed in tension or load over time.


EMI is the abbreviation for Electromagnetic Interference.

Expanded Diameter

Expanded diameter refers to the diameter of shrink tubing before heating. When heated, the tubing will shrink to its extruded diameter.

External Interference

External interference is the name for the effects of electrical waves or fields that cause spurious signals (noise) other than the intended signal.

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A farad is a unit of capacitance whereby a charge of one coulomb produces a one-volt potential difference.

Fatigue Resistance

Fatigue resistance refers to a material's resistance to metal crystallization, which leads to conductors breaking from flexing.


FDM is the abbreviation for Frequency Division Multiplexing, a method of multiplexing or combining many voice data channels on a single RF carrier. The channels are separated by frequency and carried on sub-carriers.

Filled Cable

Filled cable is a type of telephone cable construction in which the cable core is filled with a material that will prevent moisture from entering or passing through the cable.


Filler may refer to (1) a material used in multiconductor cables to occupy large interstices formed by the assembled conductors, or (2) an inert substance added to a compound to improve properties or decrease cost.

Flat Cable

A flat cable has two smooth or corrugated flat surfaces.

Flat Conductor

A flat conductor is a wire that has a rectangular cross-section as opposed to round or square conductors.

Flat Conductor Cable

A flat conductor cable has a planar construction with two or more flat conductors.

Flame Resistance

Flame resistance is the ability of a material not to propagate flame once the flame source is removed.


Flammability is the measure of the material's ability to support combustion.

Flex Life

Flex life is an educated estimate of a conductor's or cable's ability to withstand repeated bending without breakage.


Flexibility is the quality of a cable or cable component that allows it to bend under external force, as opposed to rigidity or limpness, which is a cable's likelihood of bending from its own weight.

Foamed Plastics

Foamed plastics are a type of insulation with a cellular structure.


FR-1 is a flammability rating established by Underwriters Laboratories for wires and cables that pass a specially designed vertical flame test. This designation has been replaced by the VW-1 rating.


Frequency refers to the number of cycles per second of an AC signal or an RF signal.

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Gauge is a term used to denote the physical size of a wire.


GPIB is the abbreviation for General Purpose Interface Bus Assembly, typically used for interconnecting measurement devices.


The ground in electrical terminology is the connection between an electrical circuit and the earth or other large conducting complete electrical circuit.

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Hard Drawn Copper Wire

Hard-drawn copper wire has not been annealed after drawing, which means heat has not been applied to it. Hard-drawn copper is common in tubing for above-ground services.


A harness is an arrangement of wires and cables used to interconnect electric circuits, usually with many breakouts tied together or pulled into a rubber or plastic sheath.

Hash Mark Stripe

A hash mark stripe is a non-continuous helical stripe applied to a conductor for identification.

Helical Stripe

A helical stripe is a continuous, colored, spiral stripe applied to a conductor for circuit identification.

Hermetically Sealed

Hermetically sealed refers to a gas-tight enclosure that has been completely sealed by fusion or other comparable means.

Hertz (Hz)

Hertz is a term that means cycles-per-second as a unit of frequency. One hertz signifies one event per second.


High-voltage generally means a wire or cable with an operating voltage of over 25,000 volts.


A Hi-Pot test is designed to determine the highest voltage that can be applied to a conductor without electrically breaking down the insulation.


Hook-up wire is a single insulated conductor used for low current, low voltage (usually under 1000 volts) applications within enclosed electronic equipment.


Hum is a term used to describe 60 or 120 cycle sound present in the sound of some communication equipment, usually the result of either undesired coupling to 60-cycle source or defective filtering of 120-cycle rectifier output.


Hygroscopic means readily absorbing and retaining moisture.

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IEC is the abbreviation for the International Electrotechnical Commission.


IEEE is the abbreviation for the Institute of Electrical and Electronics Engineers.

Impact Strength (Test)

An impact strength test determines the amount and force of mechanical impacts a cable can withstand without a physical or electrical breakdown. Parameters can include impacts with a given weight and drops from a given distance in a controlled environment.


Impedance is the total opposition that a circuit offers to the flow of alternating current or any other varying current at a particular frequency. It is a combination of resistance (R) and reactance (X), measured in ohms.


Inductance is the property of a circuit or circuit element that opposes a change in current flow, causing current changes to lag behind voltage changes. It is measured and expressed in henrys.

Inductive Coupling

Inductive coupling is crosstalk resulting from the action of the electromagnetic field of one conductor on another.


Insulation in wire and cable is material that has a high resistance to the flow of electric current.

Insulation Resistance (IR)

Insulation resistance is a rating that states the amount of resistance offered by an insulation to an impressed DC voltage, which can produce a leakage current through the insulation.

Insulation Thickness

Insulation thickness refers to the wall thickness of the applied insulation.

Interaxial Spacing

Interaxial spacing in wire and cable is either center-to-center conductor spacing in either paired wire or a flat cable.

Interconnecting Cable

Interconnecting cable is the wiring between modules, between units, or the larger portions of a system.


Interference is any electrical or electromagnetic disturbance that causes undesirable responses in electronic equipment.


Interstices are the spaces between individual strands in a conductor or between insulated conductors in a multiconductor cable. Interstices can change in size during extreme flexing.


IPCEA is the abbreviation for the Insulated Power Cable Engineers Association.


Irradiation, in terms of insulation, refers to the exposure of the material to high energy emissions to alter the molecular structure by cross-linking.


ISA is the abbreviation for the Instrument Society of America.


ISO is the abbreviation for the International Standards Organization.

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The jacket of a cable or wire is the outer covering, usually non-metallic, mainly used for protection against the environment.

Jumper Cable

With electrical power distribution, a jumper cable is a short flat cable interconnecting two wiring boards or devices.

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Lacquer is usually a liquid resin or compound applied to textile braid to prevent fraying, moisture absorption, etc.

Laminated Tape

Laminated tape consists of two or more layers of different materials bonded together.


The lay of a wire or cable is the length required, measuring along the axis, for a single strand (in a stranded wire) or conductor (in cable) to make one complete turn about the axis of the conductor or cable.

Leakage Current

Leakage current is the undesirable flow of current through or over the surface of an insulation.

Life Cycle

A life cycle test for wire and cable helps determine the length of time before failure in a controlled, usually accelerated, environment.

Limits of Error

The limits of error refer to the mhe maximum deviation (in degrees or percent) of thermocouple or thermocouple extension wire from standard EMF-temperature to be measured.


LOCA is the abbreviation for Loss Of Coolant Accident, a system malfunction associated with nuclear generating stations.

Local Area Network (LAN)

A local area network is a baseband or broadband interactive bi-directional communication system for voice, video or data use on a common cable or other medium.

Longitudinal Shield

Longitudinal shield is a type of tape shield, flat or corrugated, applied to the axis of the core being shielded.

Longitudinal Shrinkage

Longitudinal shrinkage is a term generally applied to shrink products denoting the discrete axial length lost through heating in order to obtain the recovered diameter.

Loop Resistance

Loop resistance is the total resistance of two conductors measured round trip from one end.

Loss Factor

Loss factor is the product of the dissipation and dielectric constant of an insulating material.

Low Loss Dielectric

Low-loss dielectric is a type of insulating material that has a relatively low dielectric loss, such as polyethylene or Teflon.

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Magnetic Field

A magnetic field is the region within which a body or current experiences or exerts magnetic forces.

Magnetic Flux

Magnetic flux is the rate of flow of magnetic energy across or through a surface (real or imaginary).

Magnetic Noise

Magnetic noise is actually the effect of a magnetic field around a cable, caused by a change in the current level, e.g. AC powerline.


Mastic is a meltable coating used on the inside of some shrink products. When heated, it melts and flows to encapsulate the interstitial air voids.


MATV is an acronym for Master Antenna Television System, a combination of components providing multiple television receiver operations from one antenna or group of antennas, normally on a single building.


MCM is the abbreviation for one thousand circular mils.


Rads and megarads are units for measuring radiation dosage. One megarad is equal to one million (106) rads.


The messenger in wire and cable refers to the linear supporting member, usually a high-strength steel wire, used as the supporting element of a suspended aerial cable. The messenger may be an integral part of the cable, or exterior to it.


Mho is a unit of conductivity. It is the reciprocal of an ohm.


MHz is the abbreviation for megahertz (one million cycles per second). This was formerly Mc.


Micro is the prefix meaning one-millionth.


Microphonics refers to noise in a system caused by mechanical vibration of its components.


A microwave is a short (usually less than 30 com.) electrical wave.


Mil is a unit used when measuring the diameter of a wire or the thickness of insulation over a conductor. One mil is one one-thousandth of an inch (0.001").


A mismatch occurs when a termination has a different impedance than the circuit or cable using it.


A modem is a DCE that places and receives data signals over a common carrier's communication facility.

Modulus of Elasticity

The modulus of elasticity is the ratio of stress to strain in an elastic material.

Moisture Absorption

This is the amount of moisture, stated as a percentage, that a material will absorb under specified conditions.

Moisture Resistance

Moisture resistance is the ability of a material to resist absorbing moisture from the air or when immersed in water.


A monomer is the basic chemical unit used in building a polymer.


MTW is the acronym for thermoplastic insulated Machine Tool Wire.


Multiplexing refers to the simultaneous transmission of two or more messages over the same cable medium. See FDM and TDM.


MUX is the abbreviation for Multiplexer.


Mylar is the DuPont trade name for a polyester material.

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A nanosecond is one-thousandth of one-millionth of a second (10-9 seconds).

National Electrical Code (NEC)

A consensus standard published by the National Fire Protection Association (NFPA) and incorporated in OSHA regulations.


NBS is the abbreviation for the National Bureau of Standards.


NEMA is the abbreviation for the National Electrical Manufacturers Association.


NFPA is the abbreviation for the National Fire Protection Association, a private trade association that provides safety standards for the National Electrical Code.

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OFHC is the abbreviation for Oxygen-Free High Conductivity copper. It has no residual deoxidant, 99.5% minimum copper content, and an average annealed conductivity of 101%.


An Ohm is a unit of resistance relative to a constant current of one ampere producing a force of one volt.


OSHA is the abbreviation for the Occupational Safety and Health Act. it is specifically associated with the Williams-Steiger law passed in 1970 that covers all factors relating to safety in places of employment.


Outgassing is often given as a percentage of a gas released during the combustion of insulation or jacketing material.


Overlap refers to the amount the trailing edge laps over the leading edge of a tape wrap.

Oxygen Index

Oxygen index is a percentage that specifies the combustion resistance of insulation or jacketing material.

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Pairing is the union of two insulated single conductors through twisting.


A pick is the distance between two adjacent crossover points of braid filaments. The measurement in picks per inch indicates the degree of coverage.


Pico is a prefix meaning one-millionth of one-millionth (10-12).


In flat cable, the pitch is the nominal distance between the index edges of two adjacent conductors.

Plastic Deformation

A plastic deformation value specifies the change in dimensions under load that is not recovered when the load is removed.


Plasticizer is a chemical agent added to plastics to make them softer and more pliable.


The plenum is the air return path of a central air handling system, either ductwork or open space over a dropped ceiling.

Plenum Cable

Plenum cable is approved by Underwriters Laboratories for installation in plenums without the need for conduit.


Polyethylenes are a family of insulations derived from the polymerization of ethylene gas and characterized by outstanding electrical properties, including high I.T. low dielectric constant, and low dielectric loss across the frequency spectrum. Mechanically rugged, it resists abrasion and cold flow.


Polymer is a material of high molecular weight formed by the chemical union of monomers.


Polyolefins are a family of thermoplastics based upon the unsaturated hydrocarbons known as olefins. When combined with butylenes or styrene polymers they form compounds such as polyethylene and polypropylene.


Porosity refers to multiple air voids in an insulation or jacket wall.


POS is the abbreviation for point-of-sale.


Potting refers to the sealing of a cable termination or other component with a liquid that thermosets into an elastomer.

Power Factor

The power factor in an electrical system is the ratio of resistance to impedance in the circuit. The ratio of the true power being used to the apparent power being delivered (kVA = V x A) is the power factor. Mathematically, the power factor correlates with the cosine of the angle between the voltage applied and the current resulting.

Primary Insulation

Primary insulation is the first layer of non-conductive material applied over a conductor, whose prime function is to act as an electrical barrier.


Propagation refers to the delay time required for an electrical wave to travel between two points on a transmission line.

Pulling Eye

A pulling eye is a device fastened to a cable to which a hook may be attached in order to pull the cable into or from a duct.

Pulse Cable

Pulse cable is a type of coaxial cable constructed to transmit repeated high-voltage pulses without degradation.

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A quad is a four-conductor cable.

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Rads are a unit of radiation dose being absorbed, equal to 100 ergs/gram.


REA is the abbreviation for the Rural Electrification Administration, a branch of the U.S. Department of Agriculture responsible for the standardization of the independent telephone companies throughout the U.S.


Reactance refers to the opposition offered to the flow of alternating current by inductance or capacitance of a component or circuit.

Recovered Diameter

The recovered diameter is the cross-sectional size of shrinkable products after heating has caused it to return to its extruded diameter.

Reference Junction

The reference junction is a junction of a thermocouple at a known reference temperature. Also known as the "cold" junction, it is usually located at the EMF measuring device.

Reflection Loss

Reflection loss is the part of a signal that is lost due to reflection of power at a line discontinuity.

Reflow Soldering

Reflow soldering is the process of connecting two solder-coated conductive surfaces by re-melting the solder to cause fusion.


Resin usually refers to a synthetic organic material formed by the union (polymerization) of one or more monomers with one or more acids.


Resistance is a measure of the difficulty in moving electrical current through a medium, when voltage is applied. It is measured in ohms.

Retractile Cable

A retractile cable returns by its own stored energy from an extended condition to its original contracted form.


RFI is the abbreviation for radio frequency interference.

Ribbon Cable

Ribbon cable is a flat cable of individually insulated conductors lying parallel and held together by means of adhesive film laminate.

Ridge Marker

A ridge marker is one or more ridges running laterally along the outer surface of an insulated wire for purposes of identification.

Root Mean Square (RMS)

Root mean square is the effective (e.g., power) value of an alternating current or voltage.

Rope Lay Conductor

A rope lay conductor is composed of a central core surrounded by one or more layers of helically laid groups of wires.


In the breaking strength or tensile strength tests, a rupture is the point at which the material physically comes apart, as opposed to the elongation yield strength, etc.

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SAE is the abbreviation for the Society of Automotive Engineers.

Self Extinguishing

Self-extinguishing material extinguishes flame after the igniting flame is removed.

Semi-Conducting Tape

Semi-conducting tape has resistance so that when applied between two elements of a cable, the adjacent surfaces of the two elements will maintain substantially the same potential. Such tapes are commonly used for conductor shielding and in conjunction with metallic shielding over the insulation.


A semiconductor is a material with electrical conductivity power between insulators and conductors.

Semi-Rigid PVC

Semi-rigid PVC is a hard semi-flexible polyvinyl chloride compound with low plasticizer content.


A separator in wire and cable is a layer of insulating materials such as textile, paper, polyester, etc. used to improve stripping qualities, flexibility, and the mechanical or electrical protection of the components.


A serve refers to a filament or group of filaments such as fibers or wires wound around a central core.

Served Wire Armor

Served wire armor is a spiral wrap of soft galvanized steel wires, wrapped around a cable to afford mechanical protection and increase the cable-pulling tension characteristics.


A sheath is the outer covering or jacket of a multiconductor cable.


In cable, the shield or shielding is a metallic layer placed around a conductor or group of conductors to prevent electrostatic interference between the enclosed wires and external fields.

Shield Coverage

Shield coverage refers to the percentage of a cable that is fully covered by the shielding material.

Shield Effectiveness

Shield effectiveness is the relative ability of a shield to screen out undesirable signals.

Shrinkage Ratio

The shrinking ratio is the ratio between the expanded diameter and recovered diameter of shrinkable products.

Shrink Temperature

The shrink temperature, much like a melting point, is the temperature that affects the complete recovery of a shrinkable product from the expanded state.

Shrink Tubing

Shrink tubing is tubing material that has been extruded, cross-linked, and mechanically expanded so that, when reheated, it will return to its original diameter.


The signal in a line is the current used to convey information, either digital, analog, audio, or video.

Signal Cable

A signal cable is designed to carry a current of less than one ampere per conductor.


Simplex is a mode of data transmission in one direction only, usually on a two-wire facility.


Sintering is the name for the fusion of a tape-wrap jacket by using high heat to a homogeneous continuum and is typically used for fluorocarbon, non-extrudable materials.

Skin Effect

The so-called skin effect is the phenomenon in which the depth of penetration of electric currents into a conductor decreases as the frequency increases.


Sleeving is a braided, extruded, or woven tube.


An SNM cable is designed for use in hazardous locations. It consists of insulated conductors in an extruded non-metallic jacket, which is then covered with an overlapping spiral metal tape and wire shield, then jacketed with an extruded moisture, flame, oil corrosion, fungus, and sunlight-resistant non-metallic material.

Soldering Sleeves

Soldering sleeves are shrinkable tubing with a solder preform used for the highest reliability soldering connections or shield grounding.

Solid Conductor

A solid conductor has a single, solid wire.


In flat cables, the span is the distance from the reference edge of the first conductor to the reference edge of the last conductor (in cables having flat conductors), or the distance between the centers of the first and last conductors (in cables having round conductors), expressed in inches or centimeters.

Spark Test

A spark test is designed to locate imperfections (usually pin-holes) in the insulation of a wire or cable by application of a voltage for a very short period of time while the wire is being drawn through the electrode field.

Specific Gravity

Specific gravity is the ratio of the density (mass per unit volume) of a material to that of water.

Specific Inductive Capacity (S.I.C.)

Specific inductive capacity is the same as dielectric constant, which refers to a material's ability to store electric energy in an electrical field.

Spiral Wrap

Spiral wrap in wire and cable terminology refers to the helical wrap of a material over a core.

Stability Factor

Stability factor is the difference between the percentage power factor at 80 volts/mil and at 40 volts/mil measured on wire immersed in water at 75° C for a specified time.

Standard Track

A standard track is a closure track used on some zipper tubing products. It allows such tubing to be readily opened or closed at any point along the installed length.

Static Condition

Static condition is a term used to denote the environmental conditions of an installed cable, rather than the conditions existing during cable installation.

Stranded Conductor

A stranded conductor is composed of single solid wires twisted together, either singly, or in groups.

Strip Force

Strip force is the amount of force required to remove a small section of insulating material from the conductor it covers (i.e., wire stripping).

Suggested Working Voltage

Suggested working voltage refers to the A.C. voltage that can be applied between adjacent conductors.

Surface Resistivity

Surface resistivity is the resistance value of a material between two opposite sides of a unit square of its surface. It is usually expressed in ohms.


A surge is a temporary large increase in the voltage or current in an electric circuit or cable.

Sweep Test

A sweep test is a method to determine the frequency response of a cable by generating an RF voltage whose frequency is varied at a rapid constant rate over a given range.

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Tank Test

A tank test is a voltage dielectric test in which the test sample is submerged in water and voltage is applied between the conductor and water as ground.

Tape Wrap

Tape wrap is spirally applied tape over an insulated or uninsulated wire.


TDM is the abbreviation for Time Division Multiplexing.

Tear Strength

The force required to initiate or continue a tear in a material under specified conditions.

Temperature Rating

The maximum and minimum temperature at which an insulating material may be used in continuous operation without loss of its basic properties.


A tempest measurement is a complex measurement of the combined reduction of all electromagnetic emissions from specified equipment used in high data security areas.

Tensile Strength

Tensile strength refers to the amount of pull stress required to break a given specimen.

Thermal Shock

A thermal shock test determines the ability of a material to withstand heat and cold by subjecting it to rapid and wide changes in temperature.


A thermocouple is a device consisting of two dissimilar metals in physical contact, which when heated will develop an EMF output.

Thermocouple Element

A thermocouple element is designed to be used as part of an assembly, but without associated parts such as the terminal block, connecting head, or protecting tube.

Thermocouple Extension Cable

A thermocouple extension cable is comprised of one or more twisted thermocouple extension wires under a common sheath.

Thermocouple Extension Wire

Thermocouple extension wire is a pair of wires of dissimilar alloys having EMF-temperature characteristics complimenting the thermocouple to be used. When properly connected, the extension wire allows the EMF to be faithfully transmitted to the reference junction.

Thermocouple Wire (Grade)

Thermocouple-grade wire provides a pair of wires of dissimilar alloys having EMF-temperature characteristics calibrated to higher temperature levels than the extension type of thermocouple hot junction. Thermocouple wire serves as the entire wire connection between hot and cold reference junctions.


Thermoplastic material softens when heated or reheated and becomes firm on cooling.


Thermoset is a material that hardens or sets because of heat, chemical, or radiation cross-linking techniques and, once set, cannot be re-softened by heating.


THHN is wire rated for 90°C, 600 volt applications. It is a nylon-jacketed building wire for dry locations. THHN stands for thermoplastic high heat-resistant, nylon-coated.


THWN is wire rated for 75°C, 600 volt applications. It is nylon-jacketed building wire designed for wet or dry locations. THWN stands for thermoplastic heat and water resistant, nylon-coated.

Tinned Copper

Tinned copper is a tin coating added to copper to aid in soldering and to inhibit corrosion.

Transmission Line

A transmission line is a signal-carrying circuit with controlled electrical characteristics used to transmit high-frequency or narrow-pulse signals.

Transmission Loss

Transmission loss is the decrease or loss in power during transmission of energy from one point to another expressed in decibels.

Tray (or Cable Tray)

A cable tray system is a unit or assembly of units or sections, and associated fittings, made of non-combustible materials forming a rigid structural system used to support cables. Cable tray systems (formerly known as continuous rigid cable supports) include ladders, troughs, channels, solid bottom trays, and similar structures.

Tray Cable

A tray cable is a factory-assembled multi-conductor or multi-pair control, signal, or power cable specifically approved under the National Electrical Code for installation in trays.

Triaxial Cable

Triaxial cable is constructed with three coincident axes, such as conductor, first shield and, second shield all insulated from one another.

Triple (Triad)

A triple, or triad, cable consists of three insulated single conductors twisted together.


Tubing refers to a tube of extruded non-supported plastic or metallic material.


Twinning refers to forming twins or pairs of wires. It is synonymous with pairing.

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UF stands for underground feeder and is a designator for thermoplastic underground feeder and branch circuit cable.


UHF is the abbreviation for ultra high frequency, 300 to 3,000 MHz.


UL is the abbreviation for Underwriters Laboratories, a non-profit independent organization that operates a listing service for electrical and electronic materials and equipment.

Unbalanced Circuit

An unbalanced circuit is any transmission line in which voltages on the two conductors are unequal with respect to ground; e.g. a coaxial cable.

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Velocity of Propagation

The velocity of propagation is the speed of an electrical signal down a length of cable compared to speed in free space expressed as a percent. It is the reciprocal of the square root of the dielectric constant of the cable insulation.


VHF is the abbreviation for very high frequency, 30 to 300 MHz.

Video Pair Cable

A video pair cable is a transmission cable containing low-loss pairs with an impedance of 125 ohms that is used for TV pick-ups, closed circuit TV, telephone carrier circuits, etc.

Volt (V)

A volt is a unit of electromotive force.


Voltage is the term most often used in place of electromotive force, potential, potential difference, or voltage drop to designate the electric pressure that exists between two points and is capable of producing a current when a closed circuit is connected between two points.

Voltage Rating

A voltage rating describes the highest voltage that can be continuously applied to a wire in conformance with standards or specifications.

Voltage Standing Wave Ratio (VSWR)

The voltage standing wave ratio is a ratio between the maximum effective voltage and the minimum effective voltage measured along the length of a mismatched radio frequency transmission line.

Volume Resistivity

Volume resistivity is the electrical resistance between opposite faces of a one-centimeter cube of insulating material; commonly expressed in ohms-centimeter.


VW-1 is a flammability rating established by Underwriters Laboratories for wires and cables that pass a specially designed vertical flame test, formerly designated F R - 1.

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Water Absorption

Water absorption refers to the percentage of weight absorbed by a material after a given immersion period.

Watt (W)

A watt is a unit of electric power. The watt is the power required to do work at the rate of one joule per second.


A wave's length (or wavelength) is the distance, measured in the direction of propagation, of a repetitive electrical pulse or waveform between two successive points.


wicking is the longitudinal flow of a liquid in a wire or cable due to capillary action.


Wire is any slender rod or filament of drawn metal.

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Yield Strength

The yield strength of a material is the minimum stress at which that material starts to physically deform.

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Find the Parts You Need at Elliott Electric Supply

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From copper wire to armored cable, we've got your electrical needs covered. With great pricing, extensive inventory, and fast delivery, you'll find no better wholesale electrical supplies distributor online than Elliott Electric Supply.

WARNING: For safety, call a licensed electrician and consult the NEC®. All licensed electricians have passed examinations covering the National Electric Code®, know state and local building codes, and may carry insurance to cover damages.