Glossary of Terms
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
A
- ABRASION RESISTANCE
- Ability of a wire, cable or material to resist surface wear.
- ALLOY
- A metal formed by combining two or more different metals to obtain desirable properties.
- ALTERNATING CURRENT (AC)
- Electric current that continually reverses its direction. It is expressed in cycles per second (Hertz or Hz).
- AMBIENT TEMPERATURE
- The temperature of the medium surrounding an object.
- AMPACITY
- The maximum current an insulated wire or cable can safely carry without exceeding either the insulation or jacket material limitations.
- AMPERE
- A unit of current; one ampere is the current flowing through one ohm of resistance at one volt potential.
- ANNEAL
- To soften and relieve strains of metal by heating to just below melting point then slowly cooling. Annealing lowers the tensile strength of copper, while improving flex life and flexibility.
- ANSI
- American National Standards Institute.
- ASA
- American Standards Association. Former name of ANSI.
- ASME
- American Society of Mechanical Engineers.
- ASTM
- American Society for Testing and Materials.
- ATTENUATION
- Reduction of signal strength during transmission. In cables, generally expressed in do per unit length, usually 1000 feet.
- AUDIO FREQUENCY
- The range of frequencies audible to the human ear. Usually 20-20,000 Hz.
- AWG
- American Wire Gauge.
- AWM
- UL designation for appliance wiring material.
B
- BAND WIDTH
- The frequency range of transmitted electrical signals, expressed in Hertz.
- BARE CONDUCTOR
- A conductor having no covering, coating or cladding on the copper.
- BEND RADIUS
- Radius of curvature: that a cable can bend before the risk of breakage or increased antenna- tion occurs. To determine bend radius a good rule of thumb is not to exceed ten times the cable diameter.
- BINDER
- A spirally served tape or thread used to hold cable components in place.
- BOND
- The attachment at an interface between an adhesive and an adherent or between materials attached by adhesive.
- BOND STRENGTH
- Amount of adhesion between surfaces, e.g., in bonded ribbon cables.
- BRAID
- A group of textile Or metallic filaments interwoven to form a tubular flexible structure which may be applied over one or more wires or flattened to form a strap.
- BRAID ANGLE
- The smaller of the two argles formed by the shielding strand and the axis of the cable being shielded.
- BRAZING
- The joining of ends of two wires or groups of wires with a nonferrous filler metal at temperatures in excess of 8OOOF / 427* C.
- BREAKDOWN VOLTAGE
- The voltage at which insulation between two conductors will fail, allowing electricity to 'arc' or pass through.
- B. & S.
- Brown & Sharpe Wire Gauge.
- BUNCHED STRANDING
- A wire composed of any number of strands twisted together in the same direction without regard to geometrical arrangement of the individual strands. Normal direction of lay is left-hand.
- BUS-BAR WIRE
- Uninsulated tinned copper wire used as a common lead.
C
- C
- Celsius.
- CABLE ASSEMBLY
- A completed cable and its associated hardware ready to install.
- CABLE FILLER
- Material used in multiconductor cables to occupy interstices in order to produce a cable that is as smooth and round as possible.
- CABLING
- Grouping Or twisting together of two or more insulated conductors to form a cable.
- CABLING FACTOR
- Used for calculating the overall diameter of a cable when multiple conductors of the same size are cabled together, D=Kd, where D is the cable diameter, K is the factor and d is the diameter of one insulated conductor'.
- CEC
- Canadian Electrical Code; Canada's version of the US National Electrical Code (new).
- CAPACITANCE
- The ability of a dielectric material between conductors to store energy when a difference of potential exists between the conductors. Cable capacitance is usually measured in Pico farads (pF) per unit length.
- CATEGORY
- Rating of a cable established by TIA/EIA to indicate the level of electrical performance.
- CATHODE
- Negative pole of an electric source.
- CATV
- Community Antenna Television.
- CCTV
- Closed Circuit Television .
- CELLULAR POLYETHYLENE
- Foamed polyethylene consisting of individual closed cells suspended in a polyethylene medium, resulting in a desirable reduction of the dielectric constant.
- CHARACTERISTIC IMPEDANCE
- The ratio of voltage to current at every point along a transmission line at the point the voltage is applied. The impedance which makes a transmission cable seem infinitely long, when connected across the cable's output terminals.
- CIGARETTE WRAP
- Tape insulation wrapped longitudinally instead of spirally over a conductor
- CIRCULAR MIL
- The area of a circle one one-thousandth of an inch (,001'') in diameter. Used in expressing wire cross sectional area and to determine conductivity and gauge size that various combinations of conductors will produce.
- CLADDING
- Method of applying a layer of metal over another metal whereby the junction of the two metals is continuously welded.
- COAXIAL CABLE
- Cable considering of two cylindrical conductors with a common axis, separated by a dielectric.
- COLD BEND
- A cold chamber test to determine effects of specified temperatures on cable which has been wrapped around a mandrill.
- COLD FLOW
- Permanent deformation of the insulation due to mechanical force or pressure.
- COLOR CODE
- A system for identifying components of cables using solid color and striped jackets.
- COMMON AXIS CABLING
- In multiconductor cables, a twisting of all conductors around a common axis yielding smaller diameter constructions.
- COMPACTED STRANDED CONDUCTOR
- A unidirectional or conventional concentric conductor manufactured to a specified diameter which is approximately 8 to 10% less than the nominal diameter the standard stranded conductor.
- COMPOSITE CABLE
- A cable consisting of two or more different types or sizes of wires.
- COMPOUND
- An insulating or jacketing material made by mixing two or more ingredients.
- CONCENTRIC STRANDING
- A group of uninsulated wires twisted around a center core with subsequent layers spirally wrapped around the core, alternating lay directions, to form a single conductor.
- CONCENTRICITY
- The measurement of the location of the center of a conductor with respect to the geometric center of the surrounding insulation.
- CONDUCTANCE
- The ability of a conductor to carry electric current; reciprocal of resistance. Measured in mhos (ohm backwards).
- CONDUCTIVITY
- The capability of material to carry electrical current, expressed as a percentage of copper conductivity with copper being 100%.
- CONDUCTOR
- A substance, usually metal, used to transfer electrical energy from point to point.
- CONDUIT
- A tube in which insulated wire and cables are run.
- CONNECTER
- A device used to physically and electrically connect two or more conductors.
- CONTACT
- The part of a connector that actually carries the electrical current', two contacts are touched together or separated to control the flow.
- CONTINUITY CHECK
- A test to determine whether electric current flows continuously throughout the length of a single wire or individual wires in a cable.
- COPOLYMER
- A polymer formed from two or more types of monomer.
- COPPER-CLAD STEEL
- Steel with a coating of copper welded to it; same as Copper weld.
- COPPER WELD
- Trade name of Flexo Wire Division (Copperweld Steel Corp.) for their copper-clad steel conductors.
- CORE
- A component(s) over which additional components (shield, sheath, etc.) are applied.
- CORONA
- A discharge due to ionization of air around a conductor due to a potential gradient exceeding a certain critical value.
- CORROSION
- Deterioration of material by chemical reaction of galvanic action.
- CRAZING
- The minute crack: on the surface of plastic materials.
- CROSS-LINKED
- Inter-molecular bonds between long chain thermoplastic polymers by chemical or electron bombardment means. The properties of the resulting thermosetting materials are usually improved.
- CROSSTALK
- The coupling of unwanted signals from one pair within a cable' to another pair, Crosstalk can be measured at the same (near) end or far end with respect to the signal source.
- C.S.A
- Canadian Standards Association; the Canadian counterpart of Underwriters Laboratories.
- CURRENT
- The rate of flow of electricity in a circuit, measured in amperes.
- CURENT-CARRYING CAPACITY
- Maximum current an insulated conductor or cable can continuously carry without exceeding its temperature rating', also cat led audacity.
- CUT-THROUGH
- A test to determine the ability of a material to withstand the application of blades or sharp edges without being cut.
D
- DC
- Direct current.
- DECIBEL
- (dB) A unit of measure to express power gaining amplifiers or power loss in passive circuits of cables.
- DERATING FACTOR
- Factor used to reduce current carrying capacity of a wire when used in environments other than that for which the value was
established. - DIELECTRIC
- A nonconducting insulating material that permits electrostatic attraction and repulsion to occur.
- DIELECTRIC BREAKDOWN
- A change in the properties of a dielectric that causes it to become conductive.
- DIELECTRIC CQNSTANT (K)
- The property of a dielectric which determines the amount of electrostatic energy that can be stored by the material when a given voltage is applied to it, Also called perceptivity,
- DIELECTRIC LOSS
- The power dissipated in a dielectric as the result of the friction produced by molecular motion when an alternating electric field is applied.
- DIELECTRIC STRENGTH
- The voltage which an insulation can withstand before breakdown occurs. Usually expressed as a voltage gradient (such as volts per mil).
- DIELECTRIC TEST
- A test in which a voltage higher than the rated voltage is applied for a specified time to determine the adequacy of the insulation under normal conditions.
- DIRECT CURRENT (DC)
- An electric current which flows in only one direction.
- DRAIN WIRE
- A non-insulated wire in contact with the shield and used in termination to that shield as a ground connection.
- DRAWING
- Pulling metal through a die or series of dies to reduce the diameter to a specific size. Wire draws down to 50 AWG are typical.
E
- ECCENTRICITY
- A measure of the center of a conductor's location with respect to the circular cross section of the insulation. Expressed as a percentage of displacement of one circle within another.
- EIA
- Electronic Industries Association.
- ELASTOMER
- Any material that will return to its original dimensions after being stretched or distorted.
- ELECTROMAGNETIC
- Pertaining to the combined electric and magnetic fields associated with movements of electrons through conductors.
- ELECTROMOTIVE FORCE (e.m.f.)
- Pressure or voltage; the force that causes current to flow in a circuit.
- ELECTROSTATIC
- Pertaining to static electricity or electricity it rest.
- ELFEXT
- Equal Level Far End Crosstalk (dB). A subtraction of attenuation from FEXT. ELFEXT negates the effect of attenuation on the interference as it propagates down the cable, thus bringing it to an "equal level".
- ELONGATION
- An increase in the length of a wire or cable caused by longitudinal tension.
- EMI
- Electromagnetic interference.
- ELECTROLYTIC TOUGH PITCH
- Copper refining process that produces a conductor that is 99.9% pure copper resulting in high conductivity.
- ETFE
- Ethylene tetrafluoroethylene, An alternating copolymer consisting of ethylene and tetrafluoroethylene segments. High impact resistance with useful mechanical properties up to 200 C.
- EXTRUDED CABLE
- Conductors are simultaneously insulated and the cable is formed by a continuous extrusion process.
- EXTRUSION
- The process of continuously forcing both a plastic or elastomer and a conductor through a die, thereby applying a continuous coating of insulation or jacket to the core.
F
- FARAD
- A unit of electrical capacity.
- FEP
- Fluorinated ethylene-propylene. A thermoplastic with excellent dielectric properties as well as chemical and heat resistance.
- FILLER
- Nonconducting components cabled with insulated conductors to impart roundness, flexibility, tensile strength, or a combination of all three, to the cable.
- FLAME RESISTANCE
- The ability of a material not to fuel a flame once the source of heat is removed.
- FLAME RETARDANCE
- Ability of a material to prevent the spread of combustion by a low rate of travel so the flame will not be propagated.
- FLAMMABILITY RATING
- The measure of the material's ability to support combustion.
- FLAT BRAID
- A woven braid, usually tinned copper, which is flattened at time of manufacturing to a specific width.
- FLEX LIFE
- The measurement of tie ability of a conductor or cable to withstand repeated bending.
- FLEXIBILITY
- The ease with which a cable may be bent.
- FLUOROPOLYMERS
- High-temperature plastics with excellent electrical properties. Examples; ETFE, FEP and PFA.
- FOAMED DIELECTRIC
- Using highly controlled extrusion processes, materials are foamed resulting in a significantly reduced dielectric constant (1.45 - 1.8) that approaches the nearly ideal properties if air without sacrificing structural integrity.
G
- GAS OUT
- A hole blown in the jacket of a cable during the extrusion process.
- GAUGE
- A term used to describe the physical size of a wire. As the AWG number gets smaller, the diameter of the wire gets larger.
- GROUND
- A conducting connection between an electrical circuit and the earth or other large conducting body to serve as an earth thus making a complete electrical circuit.
H
- HDPE
- High Density Polyethylene.
- HALOGEN
- Any of the five elements: fluorine, chlorine, bromine, iodine and astatine. These elements may be combined with insulation compounds to enhance flame retardants.
- HARD DRAWN COPPER WIRE
- Copper wire that been annealed after drawing.
- HARNESS
- An arrangement of wires and cables which have been tied together or pulled into a rubber or plastic sheath, used to interconnect an electric circuit.
- HEAT SEAL
- A method for sealing by thermal fusion.
- HEAVY TINNED COPPER
- Similar to tinned copper but with substantially greater tin thickness. Used with high frequency induction heaters to bond on the stripped area. The rest of the wire retains it's original flexibility. Acceptable under UL, CSA, ASTM, MIL and most industry standards.
- HELICAL STRIPE
- A continuous, colored, spiral stripe applied to a conductor for circuit identification.
- HENRY
- Unit of inductance such that the induced voltage in volts is numerically equal to the rate of change in current in amperes per second.
- HERTZ (Hz)
- A term replacing cycles-per-second as a unit of frequency.
- HI-POT
- Short for High Potential. A test designed to determine the electrical integrity of an insulation.
- HOOK-UP WIRE
- A single insulated conductor used for low-current, low voltage (usually under 600 volts) applications within enclosed electronic equipment.
- HOT TIN DIP
- The process of passing bare wire through a bath of molten tin to provide a coating.
- HYDROSCOPIC
- A type of material that absorbs some water from the air around it.
- HYBRID CABLE
- An assembly of two or more cables (of the same or different types or categories) covered by one overall sheath.
- HYGROSCOPIC
- Capable of absorbing and retaining moisture.
I
- IEEE
- Institute of Electrical and Electronics Engineers.
- IMPEDANCE
- The total opposition that a circuit offers to the flow of alternating current or any other varying current at a particular frequency; measured in ohms.
- INDUCTANCE
- The property of a circuit or circuit element that opposes a change in current flow, thus causing current changes to lag behind voltage changes. It is measured in henrys.
- INSULATION
- Material having good dielectric properties used to separate close electrical components, such as cable conductors and circuit components.
- INSULATION RESISTANCE (I.R.)
- Resistance to current leakage through the insulation materials.
- INSULATION THICKNESS
- Wall thickness of the applied insulation.
- INTERFERENCE
- Any undesired electrical signal introduced into a conductor by electrical or electromagnetic means.
- INTERSTICES
- Voids or valleys between individual strands in a conductor or between insulated conductors in a multiconductor cable.
- IRRADIATION
- In insulations, the exposure of the material to high energy emissions for the purpose of favorably altering the molecular structure by cross linking.
- ISO
- International Standards Organization.
J
- JACKET
- The outer protective covering of a wire and cable product; may also provide additional insulation.
K
- KILO
- A numerical prefix denoting 1000 (103).
L
- LAMINATED TAPE
- Tape consisting of two or more layers of different materials bonded together.
- LAN
- Local Area Network.
- LAY
- The axial distance required for one cabled conductor or conductor strand to complete one revolution about the axis around which it is cabled.
- LAY DIRECTION
- The direction of the progressing spiral twist in a cable while looking along the axis of the cable away from the observer, The lay direction can either be 'S'(left) or ‘Z’(right).
- LEAKAGE CURRENT
- The undesirable flow of current through or over the surface of an insulation.
- LIFE CYCLE
- A test to determine the length of time before failure in a controlled, usually accelerated, environment.
- LITZ WIRE
- A stranded (bunched) or cabled conductor made of magnet wire in which each strand is insulated from every other strand.
- LONGITUDINAL SHIELD
- A tape shield, flat or corrugated, applied longitudinally with the axis of the core being shielded.
- LOW LOSS DIELECTRIC
- An insulation material that has a relatively low dielectric loss, such as polyethylene or a fluoropolymer.
M
- MAGNETIC FIELD
- The region within which a body or current experiences magnetic forces.
- MCM
- One thousand circular mils.
- MHz
- Megahertz one million cycles per second.
- MICROPHONICS
- Electrical noise in a system caused by mechanical vibrations.
- MIL
- Unit used to measure diameter of a wire or thickness of insulation over a conductor. One one- thousandth of an inch (0.001'').
- MYLAR
- Dopant trademark name for polyethylene terephthalate (polyester) material used in form of tape.
N
- NATIONAL ELECTRICAL CODE (NEC)
- A consensus standard published by the National Fire Protection Association (NFPA) and incorporated in OSHA regulations.
- NEMA
- National Electrical Manufacturers Association.
- NEOPRENE
- A synthetic rubber with good resistance to oil, chemical, and flame. Also called polychloroprene.
- NEXT
- Near End Crosstalk (dB). Crosstalk induced on the pairs, measured at the end ''near'' the transmitter.
- NOISE
- Unwanted and/or unintelligible signals picked up on a cable circuit.
- NQMEX
- Dupont trademark for a temperature-resistant, flame retardant nylon.
- NYLON
- An abrasion-resistant thermoplastic with good chemical resistance.
O
- OFHC
- Oxygen-free high-conductivity copper (OFHC) has 99.95% minimum copper content with an average conductivity in the annealed state of 101%.
- OHM
- Unit of measure for electrical resistance. The value of resistance through which a potential difference of one volt will maintain a current of one ampere.
- OVERALL DIAMETER
- Finished diameter of a wire or cable.
- OVERCOATED COPPER
- Tinned copper strands twisted together followed by an overall tin coating. Same advantages as Prefused or Prebond copper. Acceptable under UL and CSA; not acceptable under MIL specifications.
- OVERLAP
- The amount the trailing edge laps over the leading edge of a tape wrap.
- OXYGEN INDEX
- Percentage of oxygen necessary to support combustion of a specified material.
P
- PAIR
- Two insulated wires of a single circuit associated together.
- PATCH CABLE
- A flexible piece of cable terminated at both ends with connectors. Used for interconnecting circuits on a patch panel or Cross Connect.
- PE
- Polyethylene.
- PERCENT CONDUCTIVITY
- Conductivity of a material expressed as a percentage of that of copper.
- PFA-PERFLUOROALKOXY
- A melt processions insulation with excellent thermal and electrical insulation properties including resistance to practically all chemicals, resistance to weathering, and low friction coefficient.
- PICK
- The distance from the intersection of two opposing groups of wires to the next corresponding intersection along the length of the braid. The number of picks per inch determines the density of th e braid pattern.
- PICKS PER INCH (P/I)
- The number of times the carriers in a braid cross over backs other in the same direction along the longitudinal axis for each inch of length.
- PITCH
- In flat cable, the nominal distance between the index edges of two adjacent conductors.
- PLASTICIZER
- A chemical agent added to plastics to make them softer and more pliable.
- PLATING TYPES
-
PLATING FINISHES APPLICABLE SPECIFICATION Gold Mil G 45204 Silver QQ S 365 Nickel QQ N 290 Tin MIL T 10727 Solder (60/40 - 70/30) MIL P 81728 Cadmium QQ P 416 Copper MIL C 14550 - PLENUM CABLE
- Cable approved by Underwriters Laboratories for installation in plenums without the need for conduit.
- POLYETHYLENE (PE)
- A thermoplastic material having excellent electrical properties, low dielectric constant, and very high insulation resistance. Can be stiff to very hard, depending on molecular weight and density. Moisture resistance is rated excellent.
- POLYAMIDE
- A compound characterized by more than amide group. See nylon.
- POLYIMIDE
- Available for high-temperature wire insulation in :with tape form and as a film coating.
- POLYMER
- A substance made of many repeating chemical units or molecules. The term polymer is often used in place of plastic, rubber or elastomer.
- POLYOLEFIN
- Any of the polymers and copolymers of the ethylene family of hydrocarbons, such as polyethylene and polypropylene.
- POLYPROPYLENE
- A thermoplastic similiar to polyethylene but stiffer and having a higher softening point (temperature). This tmaterial is used primarily as an insulation material. Typically, it is harder than polyethylene which makes it suitable for thin wall insulations.
- POLYURETHANE
- A class of polymers noted for good 'memory' properties, making it an ideal jacket abrasion and solvent resistance as well as outstanding material for retractile cords. Some formulations also have good flame resistance.
- POLYVINYL CHLORIDE (PVC)
- A thermoplastic material composed of polymers of vinyl chloride which may be rigid or elastomeric, depending on specific formulation.
- PREFUSED OR PREBOND COPPER
- Twisted strands of heavy tinned copper fused along it's entire length by heating. It gives the characteristics of a solid conductor but since it is comprised of individual strands it will not work-harden and break like a solid conductor might do in an application that is continually flexed. Acceptable under UL and CSA; not generally acceptable under most Mil-W-16878 types.
- PRIMARY INSULATION
- The first layer of nonconductive material applied over a conductor. lts function is to act as an electrical insulation.
- PUT-UP
- Packaging of finished wire or cable.
Q
R
- RATED TEMPERATURE
- The maximum temperature at which an electric component can operate for extended periods without undue degradation or safety hazard.
- RATED VOLTAGE
- The maximum voltage at which an electric component can operate for extended periods without undue degradation or safety hazard.
- REACTANCE
- A measure of the combined effects of capacitance and inductance on an alternating current. The amount of such opposition varies with the frequency of the current, The reactance of a capacitor decreases with an increase in frequency. The opposite occurs with an inductance.
- RESISTANCE
- In DC circuits, the opposition a material offers to current flow, measured in ohms. In AC circuits, resistance is the real component of impedance and may be higher than the value measured at DC.
- RETRACTILE CABLE
- A coiled cable that returns by its own stored energy from an extended condition to its original retracted form.
- RFI
- Radio Frequency Interference.
- DIP CURD
- A cord placed directly under the jacket of a cable in order to facilitate stripping (removal) of the jacket,
- ROHS
- Restricting the use of Hazardous Substances, A European directive that restricts the use of certain hazardous substances during manufacture of electronic/electrical products and components.
- ROPE LAY
- A wire composed from a number of bunched or concentric uninsulated wires grouped in helical layers.
- RIBBON CABLE
- A flat cable of individually insulated conductors laid parallel and held together by extrusion, bonding or woven textile yarn.
S
- SAE
- Society of Automotive Eng infers.
- SERVE
- A filament or group Qf filaments such as fibers or wires, wound around a central core.
- SHIELD
- A tape, serve or braid (usually copper, aluminum or other conductive metal) placed around or between electric circuits or cables or their components, to prevent signal leakage or interference.
- SHIELD COVERAGE
- The physical area of a cable that is actually covered by shielding material; expressed in percent.
- SHIELD EFFECTIVENESS
- The relative ability of a shield to screen out undesirable signals.
- Flexx-Sil™ RUBBER
- See here»
- SILVER PLATING
- An electrodeposited coating of silver used for engineering purposes that may be mat, bright, or semibright and are not less than 98% silver purity. Coatings of silver are usually employed for solderable surfaces, electrical contact characteristics, high electrical and thermal conductivity, thermocompression bonding, wear resistance of load-bearing surfaces, and special reflectivity.
T
- TINNED COPPER
- Has individually tinned strands. Lowest in cost of all tinned copper types. Acceptable under UL, CSA, ASTM, MIL and most industry standards.
- TOPCOATED COPPER
- Same as Overcoated copper except that bare copper strands are used. Acceptable under UL and CSA; not acceptable under MIL specifications.
- TWISTED PAIR
- Two insulated conductors twisted together.
- TWISTED TRIAD
- Any three individually insulated conductors which are twisted together.
U
- UL
- Underwriters Laboratories', a nonprofit organization performance of electronic parts and equipment.
which tests and verifies construction and - UNILAY
- More than one layer of helically laid wires with the direction and length of lay the same for all.
V
- VELOCITY OF PROPAGATION
- The speed of an electrical signal down a length of cable compared to speed ip free space expressed as a percent. It is the reciprocal of the square root of the dielectric constant of the cable insulation.
- VHF
- Very High Frequency, 30 to 300 MHz.
- VOLT
- A unit of electrical pressure. One volt is tine amount of pressure that will cause one ampere of current in one ohm of resistance.
- VOLTAGE
- Electrical potential or electromotive force expressed in volts.
- VOLTAGE RATING
- The highest voltage that may be continuously applied to a wire in conformance with standards or specifications.
W
- WALL
- The thickness of the applied insulation or jacket.
- WATT
- A unit of electrical power. One watt is equivalent to the power represented by one ampere of current under a pressure of one volt in DC circuit.
- WICKING
- The longitudinal flow of liquid in a wire or cable due to capillary action.
X
Y
Z
- ZIP CORD
- Two or more independently insulated conductors in a parallel configuration that can early be pulled apart leaving the insulation of each conductor intact. May be extruded together or extruded independently and later bonded together.