DEFINITIONS and EXPLANATIONS
Abrasion-resistance: A measure of the ability of tubing to resist damage by mechanical means.
Adhesive Liner: Lining that melts and flows inside a sleeve filling any voids in between the substrate and the sleeve.
Aging: Change in the properties of a material over time and under specific conditions. Generally refers to the environmental stimulus such as heat and light.
ASTM (American Society for Testing and Materials): A nonprofit industry wide organization that formulates test methods and material specifications, and publishes standards, testing methods, recommended practices, definitions, and other materials.
AWG: Acronym for American Wire Gauge. Conductors are classified under a standard which defines each gauge representing a solid conductor and which one or more stranded conductors correspond to, along with the associated properties for that gauge such as diameter, circular mil area, and DC resistance.
Backshell: A enclosure designed for anchoring cable or wire, and made to attach to the back side of a connector. It provides a mechanical strain relief to the cable or wire to significantly reduce stress transmitted through to the wire/contact connections inside the connector.
Braid: A woven metallic or fiber layer applied over wire or cable to act as a protective barrier or shielding.
Brittle Temperature: The temperature below which a material becomes brittle, often measured by a cold impact test.
Chemical Resistance: The ability of the insulation to withstand exposure to and resist damage by chemicals and substances. Exposure can range from immersion to occasional contact. Six basic types of chemicals are:
Acids: can be organic or inorganic; have a tendency to dissociate in water to partially or completely ionized in solution; typical organic acids are citric acid, carbonic acid, hydrogen cyanide, lactic acid, and salicylic acid; typical inorganic acids are sulfuric acid, phosphoric acid, nitric acid, hydrogen sulfide, and hydrochloric acid.
Alcohols: organic compounds with the general formula R-OH, in which R represents an alkyl group and -OH represents one or more hydroxyl groups; typical compounds are methanol, ethanol, glycols, and isopropanol; used in antiseptics, cough syrups, medications, cleaners, coatings, shellac, dyes, inks, fuel additives, cosmetics, perfumes, and as base materials for plasticizers, synthetic lubricants.
Aliphatic hydrocarbons: organic compounds whose carbon atoms are joined in straight or branched chains instead of rings; typical compounds are mineral spirits, paint thinner, petroleum distillate, and cyclohexane; found in oil and alkyd based coatings, pesticides, furniture oils, cleaners, and some cosmetics.
Alkalis: hydroxides of an alkali metal (lithium, sodium, potassium, rubidium, cesium, francium, beryllium, magnesium, calcium, strontium, barium, radium); easily soluble in water and form basic solutions; neutralizes acids, forming salts and water; typical alkalis are sodium hydroxide, sodium bicarbonate, calcium hydroxide, and calcium carbonate.
Aromatic hydrocarbons: organic compounds that contain at least one ring of six carbon atoms, each joined to at least two other carbon atoms; typical compounds are toluene, xylene, phenol, benzene, and styrene; found in enamel paints, paint strippers, some lacquer coatings, in gasoline, in engine cleaners, in styrenic plastics, phenolic resins, creosol preservatives, and some pesticides.
Oils: describes a variety of greasy fluid substances that are typically viscous liquids at room temperature, less dense than water, insoluble in water but soluble in alcohol, and usually flammable; the wide range of compositions make generalizations not useful, but they can be grouped; groupings would be petroleum/hydrocarbons, fats/oils, and volatile oils; petroleum/hydrocarbons are used as fuels, solvents, and lubricants; fats/oils are used in soaps, lubricants, foods and food preparation; volatile oils occur in plants, evaporate through exposure to air, and provide attributes such as flavor and odor.
There are other additional types not listed.
Coiled Cord: Cable formed into the shape of a spring by winding cable around a mandrel, and heat set into that shape (also referred to as retractile cordset). This permits the extension of a coiled cord to a length from 3 to 5 times it's length at rest. A coiled cord will typically return, after being extended and released, to a length similar to it's original length at rest.
Cold Blend: A test conducted by rapping tubing around a mandrel or by bending it in an arc while at a low temperature.
Conductor: An uninsulated metal wire capable of carrying electrical current. There are three generic types of conductors: solid, stranded, and tinsel. A solid conductor consists of one solid wire, and a stranded conductor consists of two or more solid wires twisted together. A tinsel strand comprises wire(s) flattened into a ribbon, with the ribbon(s) wrapped around a fiber. A tinsel conductor consists of either a single tinsel strand, or of two or more tinsel strands twisted together.
Conductor Material: A type of metal used to make wire for conductors. The most commonly used material is ETP copper (usually referred to as copper). A special grade of copper is OFHC copper, which is oxygen-free, high conductivity copper.
Alloys of copper are used for applications needing higher strength, or longer flex life, or greater reliability. These alloys are normally Cadmium bronze (also known as Cadmium copper). Less frequently used alloys are Cadmium chromium copper, Phosphor bronze, and Silicone bronze.
Conductor, stranded: Solid wires twisted together, or groups of twisted solid wires which are then twisted together. The most common types of stranded conductors are 7 twisted wires (7 strand), or 16 twisted wires (16 strand), or 19 twisted wires (19 strand). Other strandings are 37 twisted wires, 63 twisted wires, and 127 twisted wires. Concentric stranded conductors are twisted in progressive layers of 6 wires around 1 wire (7 strand), or 12 wires around 6 wires around 1 wire (19 strand), and 18 wires around 12 wires around 6 wires around 1 wire (37 strand). Bunch stranded conductors are twisted together at one time rather than in layers. Bunch stranded conductors are typically either 16, 19, 26, 28, 37, or 40 twisted wires.
The finished AWG (guage) of a conductor is determined by the number of strands (of wire) based on the AWG of the wire itself. For example, 7 strands of a 34 AWG wire will result in a 26 AWG conductor. A complete listing of the strand and AWG combinations can be found in our Stranded Conductors chart.
Conduit: A tubular raceway for holding wires or cables.
Continuity: A continuous path for the flow of current in an electrical circuit
Continuous Operating Temperature: Maximum temperature at which a component will maintain an acceptable lifetime performance, based on accelerated aging prediction.
Crosslinking: The formulation of bonds between molecular chains in a polymer by means of chemical canalization or electron bombardment. The properties of the resulting thermosetting material are usually improved.
Crosslinking by Irradiation: A method of crosslinking polymers that makes a nonflowing material. This generally improves the properties of the polymer.
CSA (Canadian Standards Association): An agency that has developed standard specifications for products with particular emphasis on safety in the end use.
Dielectric Strength: The maximum voltage a dielectric can withstand without rupture. Usually expressed as volts per mil.
Elastic Memory: The ability of a crosslinked polymer to be deformed to some predetermined shape, hold that shape for a period, and then return to its original shape upon application of heat.
Elastomer: A material that exhibits very low or zero crystallinity and a high degree of flexibility.
Elongation: The ultimate elongation, or elongation at rupture. Expressed as a percentage of the original strength.
EMI Filtering: The reduction in strength of electromagnetic fields and noise that can interfere with and alter a valid transmitted signal traveling in/on a metallic wire. This is typically accomplished by shielding; it can also include use of ferrites or toroids, and/or capacitive couplers.
Encapsulation: Covering and sealing.
Environmentally Sealed: Description of a system to keep out moisture, dirt, air, or dust that might reduce performance.
Expanded ID: The specified minimum (as supplied) internal diameter of tubing.
Extrusion: A process that conveys plastic insulation material, generally via a screw, through forming dies and subsequently cools the insulation material to form a predetermined shape.
Flame-Resistant: A descriptor applied to material that is inherently resistant to burning.
Flame Retardant: A descriptor applied to material that has been made or treated so as to resist burning.
Flammability Rating: Test methodologies of various organizations designed to simulate exposure to flame and burning, and the results of a material when tested under a specific methodology. Frequently used tests are UL94 (for testing materials as slabs or plaques), UL VW-1 or CSA FT1 (testing cable in a vertical orientation), NEC CL2 (testing cables for general purpose use which are installed within buildings), NEC CM (testing cables for general purpose communications which are installed within buildings), CSA FT6 (testing cable for horizontal flame and smoke).
Flex Life: The ability of a cable or assembly to withstand repeated bending.
Flex Life Test Types: Testing methodologies used to evaluate the durability and reliability of a cable or assembly under repeated bending. Three methods are frequently used: Weighted Bend, Bend, or Rolling Bend. The Weighted Bend test holds a section of the cable aligned within a fixed holder, and with a weight attached to the cable below the holder (applied load). At a specified distance from the holder, the free end is bent to a 90 degree angle in one direction, and then reversed to a 90 degree angle in the opposite direction. This is one flex cycle.
The Bend test is the same as the Weighted Bend test without a weight (no load) attached to the cable.
The Rolling Bend test holds one end of the cable in a fixed holder, the cable is formed into a U shape, and the free end of the cable is moved back and forth keeping the sides of the U at a fixed distance apart during the cycling.
Fluoropolymer: A polymer that contains atoms of fluorine. Typical fluoropolymers are TFE, FEP, PFA, ECTFE, ETFE, and PVF.
Gauge: A term used to denote the physical size of the wire.
Halogen-Free: A designation for gases produced during flame and burning of materials or cables. Halogen-free materials do not release potentially toxic chlorine or fluorine gases. Toxicity of gases under flame and burning conditions is a factor in persons' survivability. There is a test methodology for toxicity which is CTI, and the test method is UTE C 20.
Halogen Rating: Identifies if a thermoplastic polymer, elastomer, or thermoset rubber has or contains halogen elements. Halogen is an electro-negative atomic element which, if combined with a metal, forms a haloid salt. Halogens are chlorine, fluorine, bromine, iodine, and astatine. Halogen containing compounds, if exposed to flame, produce corrosive and potentially toxic fumes. Materials can be identified as either halogen-free or as halogenated.
Hardness: A general term that correlates with strength, rigidity, and resistance to abrasion or penetration. Measured on Shore or Rockwell scales.
Heat-shrinkable: A polymeric material capable of being reduced in size when exposed to heat.
Hybrid: Cable which contains both optical fiber(s) and metallic conductor(s)
ID.: The internal diameter of a tubing.
Insulated Terminal: A solderless terminal with an insulated sleeve over the barrel to prevent a short circuit in certain installations.
Insulation, conductor: A non-metallic covering applied around a metallic conductor or optical fiber to provide electrical isolation and/or mechanical protection and/or moisture protection.
Irradiation: In insulations, the exposure of the material to high-energy emissions for the purpose of favorably altering the molecular structure via crosslinking.
Jacket: An non-metallic protective covering applied around an insulated conductor, an insulated optical fiber, or around one or more bundles of insulated conductors and/or insulated optical fibers. A cable may optionally have one or more inner jackets and will have one outer jacket.
Lacing Cord or Twine: Used for lacing and tying cable forms, hookup wires, cable end, cable bundles, and wire harness assemblies. Available in various materials and impregnates.
Lacing Cord or Twine: Used for lacing and tying cable forms, hookup wires, cable end, cable bundles, and wire harness assemblies.
Longitudinal Change (Shrink Tubing): The change in length of tubing when recovered. Expressed in the percent change from the original length.
Lot Number: The number that identifies one production run of material.
Marking: A printed identification number or symbol applied to the surface of tubing or cable jackets.
Melting Point: The temperature at which crystallinity disappears when crystalline material is heated.
Mil: A unit equal to one one-thousandth of an inch (.001").
MIL-SPEC: Abbreviation for Military Specification, which is a document that the U.S. Government issues to define a product that will be used in military end-use applications.
Nominal: A descriptor applied to a dimension representing the center of the range of tolerance or a value if no tolerance is applied.
OFT (Optional Flame Test): Canadian Standards Association's test for flame retardance. Tubing with an OFT rating is highly flame-retardant.
Operating Temperature: The maximum internal temperature at which a system, harness, or connector may operate in continuous service, generally expressed as a time and temperature.
Pigtail: A free end of a retractile cordset which is not formed into a coil. A cordset will typically have two pigtails.
Pigtail Orientation: A pigtail may be approximately perpendicular to the axis through the center of the coil of a cordset, and this is referred to as a dropped pigtail or perpendicular pigtail. A pigtail may be approximately parallel to the axis through the center of the coil, and this is referred to as a turned-out pigtail or an axial pigtail.
Plasticizer: A softener or lubricant added to a compound that makes it easier to process or more flexible in use.
Plating: A thin coating of metal overlaid onto metallic components or wire to improve conductivity, facilitate soldering, or prevent corrosion. Typical platings for wire are tin (hot dipped or electrolytic) or silver. Platings of gold or nickel are used for very specialized wire applications.
Polyamide: A polymer formed by the reaction of a diamine and a diacid. Nylons are commercial polyamides characterized by toughness, solvent resistance, and sharp melting point.
Polyolefin: A family of polymers (such as polyethylene and polypropylene) made from olefin monomers.
PVC: (Polyvinyl Chloride): A polymer compound used as wire insulation.
PVDF: Polyvinylidene fluoride.
Rated Temperature: The maximum temperature at which a component can operate for extended periods with acceptable changes in its basic properties.
Rated Voltage: The maximum voltage at which a component can operate for extended periods without undue degradation.
Recovered ID: In heat-shrink tubing the guaranteed maximum internal diameter of tubing after being freely recovered.
Retractile Cordset: Cable formed into the shape of a spring by winding cable around a mandrel, and heat set into that shape (also referred to as coiled cord or cordset). This permits the extension of a cordset to a length from 3 to 5 times it's length at rest. A cordset will typically return, after being extended and released, to a length similar to it's original length at rest.
Retractile Springback: The rate of the coiled portion of a cordset, when released from being held in an extended position, to return to it's approximate original length. Springback, in simplest terms, can be specified as rapid, medium, or controlled.
Sealant: Soft, tacky, pliable material that seals where mechanical strength is not required.
Shelf Life: Generally, the length of time a product or material may be stored without deterioration. Specifically, the length of time during which shrink tubing will retain its expanded ID and return to its recovered ID.
Shielding: Strands or tapes of conductive material, which can be formed into a braid, or spiral wrap, or longitudinal cover, around insulated conductors or cable to reduce signal interference. Typical shielding materials are copper, tin or silver plated copper, and aluminum.
Shield Coverage: The physical area of a conductor or a bundle of conductors that is covered by the shielding material and is expressed in percent. The maximum shield coverages for types of single shields are: Braid - 95%; Spiral Strand - 97%; Foil - 100%.
Shield Effectiveness: The ability of a shield to block undesirable signals from passing through the shield, usually expressed in dB. Shield effectiveness for any type of shield and for any shield material varies as frequency varies.
Shield, Dual: A set of two shields in which one shield is adjacent to and surrounds another shield. Dual shields provide higher shield effectiveness over a broader range of frequencies. Dual shields typically consist of a foil shield, surrounded by either a spiral strand or braid shield.
Shore: A scale for comparing hardness. Higher shore values represent harder materials.
Shrink Ratio: An expression of how much the inside diameter of shrink tubing will reduce in size when recovered. The inverse of the expansion ratio.
Smoke Density Rating: Test methodologies of various organizations designed to simulate smoke density generated during flame and burning, and the results of a material when tested under a specific methodology. Several tests are typically used: NBS Smoke Density per ASTM E662, OSU per FAR 25, NBS Smoke Density per ISO 5659, IF index per NFF 16 or Smoke Density per NFX 10. Smoke density is designing to evaluate the visibility for escape from a burning area.
Solvent Resistance: The ability of a material to retain physical and electrical properties after being immersed in specific solvents.
Specific Gravity: The ratio of the density (mass per unit volume) of a material to that of water.
Strain Relief: The technique for or act of removing or lessening the strain or stress on a joint, splice, or termination
Temperature Rating: The maximum temperature at which the insulating material may be used in continuous operation without loss of its basic properties. Usually time dependent.
Tensile Strength: The pull stress (in force per unit area) required to break a given specimen.
Thermoplastic: A material that softens (melts or flows) when heated and becomes firm when cooled. A type of plastic that can be re-melted a number of times without any important changes in properties.
Tolerance: The total amount by which a quantity is allowed to vary from nominal; thus, the tolerance is half the algebraic difference between the maximum and minimum limits.
UL (Underwriters' Laboratories): A non-profit organization which offers recognition of electrical and electronic components including cable and assemblies. UL Recognition is a group of classifications of electrical or electronic products based on intended use. UL does not approve products for a particular use.
UL Style: A numeric code, usually four digits, used to describe a type of construction of cable which typically specifies a range of conductor AWGs, an insulation material or materials, jacket material and thickness, a temperature rating, and other parameters.
Ultraviolet Degradation: The degradation caused by long-time exposure of a material to sunlight or other ultraviolet radiation.
Volume Resistivity: Reciprocal of conductivity; the resistance of a material to the flow of electrical current, usually expressed in ohm-cm.
VW-1: A rating determined by the Underwriters' Laboratories (UL) optional Vertical Wire Flame Test - the most difficult flame test for tubing. Tubings with a VW-1 rating are highly flame-retardant.
Wall Thickness: The thickness of the tubing or cable jacket wall.
Wicking: The longitudinal flow of a liquid in a wire or cable construction due to capillary action.