Resources

Glossary Of Terms

TermDescription
AASHTOAmerican Association of State Highway and Transportation Officials. Governing body responsible for the following pole specification: "Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals." (Also called LTS-2)
ACORN NUTDecorative anchor bolt nut with enclosed rounded top.
AGENTRepresentative of manufactured products and responsible for communication, sales and service of customers within a specified region.
AISCAmerican Institute of Steel Construction
ALLOWABLE STRESSMaximum permissible stress as defined by design criteria.
ALLOYA compound mixture consisting of one or more base elements (metal) to achieve desired physical or mechanical properties.
ALLOY-STEELA type of steel that contains additional elements to improve its  properties.
ALUMINUMA silver-white non-ferrous metallic element whose features and physical properties include: a good resistance to temperature variations, high reflectivity, resistance to oxidation, ductility, light weight, and recyclable.
ANCHOR BASEBase plate used to anchor poles to ground.  See also "Base Plate" & "Fixed Base".
ANCHOR BOLTThreaded steel rod embedded into concrete and used to connect the pole to the foundation.
ANGLE IRONPiece of structural steel rolled or formed into an "L" shaped cross section.
ANODIZINGThe process of coating a metallic surface electrolytically. This process normally involves the combination of electrical current and chemical bath in which the material's surface or "skin" is altered to form a protective shield for the remaining material thickness.
ANSIAmerican National Standards Institute
APPROVAL DRAWINGFormal drawing submitted to customer for their review to determine acceptability of product.
ARCHITECTURAL COATINGSpecial finish coating designed to give the appearance of concrete, marble, granite or sandstone.
ARGONInert gas element utilized as a shielding component of "gas metal arc welding" (GMAW) or "metal inert gas welding" (MIG). Generally utilized when welding aluminum or like materials.
ARMA single extension of any cross section used to mount a single fixture.
ARM RISEThe vertical distance from the center line of the simplex connection to the center line of the arm end.
ARTIFICIAL AGINGProcess of heating and cooling a material in a controlled manner to develop desired mechanical properties. (See also heat treat).
ASTMAmerican Society for Testing and Materials
ASTRO BRACKETDevice used to attach a traffic signal to the pole or mast arm. Normally rigid mounted, but can also be free swinging.
AWSAmerican Welding Society
AXIAL FORCEForce along the longitudinal axis of a member. When designing a foundation this figure relates to the weight of a structure plus any added devices or equipment.
BACKPLATEBorder surrounding traffic signal heads.
BACK-UP-BARSteel bar used to secure the handhole cover.
BACK-UP-RINGSteel ring used for full-penetration welded connections.
BANNER ARMSOne or two parallel pipe extensions coupled or clamped perpendicular along the pole shaft that is used to mount a special banner.
BASE COVERSee "Full Base Cover"
BASE FLANGECast component welding to the bottom of the pole shaft used to connect the structure to the foundation. (Also called base casting and shoe base).
BASE PLATESteel plate welded to the bottom of the pole shaft used to connect the structure to the foundation.
BASE REACTIONS (POLE)Shear force, axial force, and bending moment occurring at the pole base, used for foundation design.
BEARING PLATESteel plate attached to the bottom of an anchor bolt designed to prevent bolt pull-out.
BEND RADIUSThe radial dimension corresponding to the curvature of a bent member, usually measured from the inside surface.
BENDING LOADA force that is applied in the middle or on the end of an object causing the object to bend in a curve.
BENDING MOMENTThe product of a wind force or weight force multiplied by its distance from a section.
BOLTMetal rod or pin used for fastening objects together that usually has a head at one end and a screw thread at the other.
BOLT CHORDDimension measured between two adjacent anchor bolts which do not intersect the center line of the foundation. This dimension may vary between each individual chord.
BOLT CIRCLEDimension measured from one anchor bolt to another which intersects the center line of the pattern. This dimension will remain equal for all bolts, regardless of quantity of bolts.
BOLT COVERA decorative cast cover usually fastened to the base flange covering the anchor bolt.
BOLT FRACTUREA type of fastener failure that occurs when a fastener is over-tightened and causes the bolt to break.
BOLT LOADForce along the axis of a bolt.
BOLT PROJECTIONLength of anchor bolt extending above the foundation surface.
BREAKAWAY COUPLINGDevice used to connect the pole to the anchor bolts, and designed to fracture when the pole is impacted by a vehicle. The main purpose being to assure passenger safety.
BRINELL SCALEA method for testing a material's hardness that forces a hard steel sphere under a specified load into the surface of a material and measuring the diameter of the indentation left after the test.
BRONZEAn alloy of copper and tin.  Bronze is highly corrosion resistant.
BULLHORNSteel pipe formed with a 90 degree upward bend used to mount fixtures, speakers, cameras, etc.
BUMP FORMEDMethod of manufacturing a flat steel plate into structural shape. The plate is bent by a brake press usually at equal spacings, forming the desired shape.
BUTT WELDCircumferential weld joint used to connect two shaft sections or a shaft to a plate with or without a back-up ring.
C.B.CCanadian Building Code
C.S.ACanadian Standards Association
C.S.R.(Combined Stress Ratio) Summation of ratios of applied stresses over allowable stresses. Included stresses are bending, shear and axial.
C.W.B.Canadian Welding Bureau
CADComputer-Aided Design
CAGE PLATFORMA platform that consists of formed steel tubing, support angles and steel grating to safely support a service person and a cluster of lighting fixtures.
CALCULATIONSFormal structural analysis to be presented to the customer, proving adequacy of the structure to the design criteria requirements.
CAMBERCurving of sign structure chords, mast arms or poles during the manufacturing process. The curved displacement from center line is equal and opposite to the deflection expected in the field. The structure, therefore, appears straight after loads are applied.
CANTILEVERStructure fixed at one end and free at the other. A pole is a vertical cantilever and a mast arm is a horizontal cantilever.
CARBON STEELA type of steel made up of iron and carbon and no other material.  Most fasteners are made from carbon steel.
CASTINGProduct which is manufactured by means of molding in a form with a molten alloy.
CERTIFICATIONA document containing a confirmation that the product and/or design meets or exceeds some specifically stated conditions.
C-HOOKSteel rod formed into shape of a "C" and used for wire support or handling purposes.
CITY SCAPEUnique design style in traffic control and lighting structures incorporating modular components.
CLAMPING FORCEThe compressive force that a fastener exerts on a joint.
CLAMSHELL BASEA 2-piece shell base bolted around the pole base after installation.
CLEARANCEThe vertical distance from the roadway surface to the lowest point of an overhanging device.
COATINGProcess of covering a product with one of or a combination of the following: galvanizing, painting and/or metallizing.
COBRA HEADGeneric term for some street lighting fixtures.
COIL MATERIALAny steel which is rolled into coil form after processing from the mill.
COLD WORKINGThe shaping of metal at temperatures much lower than the metal's molten state.  Cold working increases the yeild strength in certain steels.
COMPRESSION LOADA pushing or pressing force that is directed toward the center of an object.
CONTROLLER CABINETMetal cabinet that houses components used to operate the electrical system. Components could include items such as terminal strips, timers, and circuit breakers.
COPPERA reddish-brown metal that is very ductile, thermally and electrically conductive, and corrosion resistant.  Copper fasteners are often used for electrical components.
CORROSIONThe gradual chemical attack on a metal by atmosphere, moisture, or other agents.
CORROSION RESISTANCEThe ability of a material to resist chemical destruction from an environment.  Corrosion resistance is the most important physical property for fasteners.
COR-TENTrade name by United States Steel Company for high strength, low alloy, self-weathering steel. This material has enhanced atmospheric corrosion resistance when compared with ordinary carbon steels. The enhanced corrosion resistance may permit the use of this steel in the uncoated (non-galvanized or unpainted) condition.
COUPLINGInternally threaded steel fitting used for wiring access and attachment of controller cabinets, junction boxes or other related devices.
CRITERIAA written specification used to control the design of a structure.
CROSSARMA length of steel tubing or angle that attaches to a pole shaft with provisions for mounting a single row of lighting fixtures.
DAMPERMechanical device used to eliminate or reduce harmonic vibrations. (See also vibration damper and harmonic vibrations).
DAVITRadial formed pole/luminaire arm.  A radiused (single member) luminaire arm that attaches to the vertical top of the pole.  This type of arm gives the pole and arm the appearance of being a single member.
DEAD LOADTotal weight of structure and all added appurtenances.
DEFLECTIONMovement of the pole and/or arm, expressed as a displacement or rotation, resulting from dead loads or other applied loads.
DENSITYThe relative compactness of a material.  Density is the mass of a material per unit volume.
DERATERecognizing a material's loss of physical or mechanical properties due to a manufacturing process such as welding.
DIE CASTINGThe process where molten metal is forced under pressure into the cavity of a mold to form a desired shape such as a base flange or base casting.
DRAG COEFFICIENTA numerical factor used in wind force calculations. This factor is applied to the projected area of a structural member, lighting fixture, traffic signal, or other component to account for its shape.
DRILL PATTERNLayout of hole size and spacing for a given fixture.
DUCTILITYThe ability of a material to deform before it fractures.
DUPLEX RECEPTACLEElectrical component generally used in conjunction with Valmont festoon box.
EFFECTIVE PROJECTED AREA (EPA)Area of a given fixture and/or structure resisting wind force (projected area times the appropriate drag coefficient).  Most luminarie manufacturers list EPA ratings of their fixtures in their catalog. The EPA of luminaire arms such as a truss arm, and any other such equipment used, must be added to the luminaries EPA to determine the total EPA capacity of the pole.
ELASTIC LIMITThe maximum stress a material can support before it deforms.  Elastic limit is also known as yield strength.
ELECTRICAL CONDUCTIVITYThe ability of a material to conduct an electrical current.
ELEVATIONThe distance which something is above or below sea level, ground level or other referenced surface. (i.e., highway, foundation, etc.)
ELLIPTICALHaving the shape of an oval.
ELONGATETo extend the length of a material.
EMBEDDED POLEPole fixed into concrete or compacted soil by means of an extended portion.
EXTRUSIONThe process of forcing material through a die to form a desired cross-section shape.
FASTENERA part used to attach or secure two components together. (i.e., bolt, nut, screw, etc.)
FATIGUEA type of failure that occurs when a material is subjected to repetitive loading or stressing.  Fatigue can cause catastrophic failure.
FATIGUE STRENGTHThe maximum stress a material can withstand for a specific number of repeated applications prior to its failure.
FERROUSA metal that contains iron.  Carbon steels are common ferrous metals.
FERRULESee "Tenon"
FESTOON BOXEnclosure welded to a structure to accommodate the mounting of an electrical component.
FINIALA sculptured ornament located at pole top or end of arm.
FINIAL CAPCast or spun decorative pole top cap.
FINISHA protective and usually decorative coating applied to structures and their components. (i.e., galvanizing, prime painting, finish painting, etc.)
FIXED BASEType of pole-to-foundation attachment not designed to breakaway if impacted by a vehicle.
FIXTUREA lighting fixture, which provides artificial light.
FLOOD LIGHTA lighting unit for projecting a broad beam of light. Used in parking lots, sports fields, and other area lighting applications.
FLUTINGThe formation of rounded grooves using rollers or other means to create a decorative motif on the shaft or column.
FORCEVector quantity that tends to produce stress and deflection in the structure to which it is applied.
FOUNDATIONThe earth-embedded support element for a pole structure, normally consisting of concrete, steel reinforcing bars and anchor bolts.
FRANGIBLE BASEPole base that is designed to breakaway when struck by a vehicle. (See also "Breakaway Coupling", "Transformer Base" and "Slip Base")
FULL BASE COVERDecorative shroud used to enclose the base plate and anchor bolts.
GALVANIZEA zinc coating applied by a hot dip process or other approved method.
GASKETA natural or synthetic rubber seal used between piece parts to prevent the intrusion of moisture.
GAUGEA whole number representing an equivalent decimal thickness. (i.e., 11 = 0.1196, 7 = 0.1793, 3 = 0.2391)
GRADEA category that materials are grouped in according to their strength.
GRADE IDENTIFICATIONThe marking on the head of a bolt that indicates tensile strength.
GROMMETA natural or synthetic rubber ring placed in drilled wireway holes to prevent chafing or damage to wires.
GROUNDING PROVISIONA drilled and tapped hole located near the hand hole to allow attachment of the ground connection and grounding wire.  It can also be directly drilled and tapped on the interior base area of a decorative Designer Series base.
GROUTA mortar used for filling space between the bottom of the pole baseplate and the top of the foundation.
GUSSETSteel plate used to strengthen a welded connection.
GUST FACTORA numerical factor, usually 1.3, applied to a constant wind velocity to account for an instantaneous outburst of wind.
HANDHOLEReinforced opening providing internal access to a structure.
HARDNESSThe measure of a material's ability to resist penetration, indentation and scratching.
HARMONIC VIBRATIONA sustained back-and-forth motion of a member moving the same distance in opposite directions.
HEAT TREATProcess of heating and cooling a material in a controlled manner to develop different mechanical properties.
HEAT TREATMENTThe heating and cooling processes used to change the structure of a material and alter its mechanical properties.
HEIGHT COEFFICIENTA numerical factor applied to the design wind pressure to account for the increased wind pressure experienced due to smoother flow of air at higher elevations above ground.
HEX-HEAD BOLTA type of bolt that has a head with six sides.
HIGH MASTStructures designed to light a large area by providing a point of fixture attachment higher than an average area lighting structure. A high mast pole is usually equipped with a lowering device system.
HINGED POLEStructure design allowing ease of pole top access using a hinge by which the pole top can be lowered to ground level.
IMPACT ATTENUATORA device used on a safety climbing cable to reduce the severity of the jolt encountered when a falling person reaches the end of the safety belt lanyard.
INDENTERA device used in a hardness test that is pressed into the test material.
ISOMETRIC DRAWINGA drawing in which three faces of a solid object are shown with the lines parallel to the edges and drawn in true length.
ISOTACHA line on a map connecting points of equal wind speed. A gust factor is usually applied to the isotach wind speed.
ISOTACH WINDMAPThis is a mean occurrence wind map produced by the National Environmental Data Service, which gives the 50-year wind velocity for each area of the country.  These 50-year wind values are used in designing poles.
JACKING LUGSSteel nuts welded to a pole shaft to facilitate the process of slip fitting pole sections together.
JAM POLESee "Laminated Shaft"
J-HOOKSteel rod formed into the shape of a "J" used for wire support or handling purposes.
KEEPER PLATEA thin steel plate (usually 20, 22 or 28 gauge) used to keep the connecting bolts of a slip base assembly in place.
KIPUnit of measure equivalent to 1000 pounds.
K-KLADA custom formulated thermosetting polyester resins, curing agents, pigments and modifiers, to meet specific end-use requirements for durability, chemical resistance, and UV protection. Resins and pigments are mixed while molten and then cooled and solidified. The resulting material has a completely uniform composition. The cooled material is then ground to the desired particle size for application to the metal.
K-SEALA thermal plastic hydrocarbon resin system specially formulated for application over untreated steel surfaces. K-Seal is also used to complete the KW's K-KLAD coating system.
KSIKips per Square Inch
LAMINATED SHAFTTapered steel tube resulting from firmly pressing together two separate tubes, one inside the other, to increase wall thickness.
LIGHTNING RODMetallic rod attached to a pole structure creating a continuous conducting path to the ground to diminish the destructive effects of lightning.
LIQUID COATFinish applied to a material in a liquid form.
LIQUIDATED DAMAGESThe determination of liability by means of agreement or litigation as to the amount of indebtedness.
LMALuminaire Mast Arm
LOADThe overall force that is applied to a material or structure.
LOCK WASHERA split washer used to prevent loosening by exerting pressure on a nut.
LOCKNUTA nut tightened down on another, or a nut so constructed that it locks itself when tightened. Both types are used to prevent loosening.
LOW-CARBON STEELA type of carbon steel that contains less than 0.3% carbon.  Grade 2 fasteners are common low-carbon steel fasteners.
LOWERING DEVICEApparatus capable of lowering fixtures to ground level for ease of maintenance.
LUG WASHERSteel plate washer used in transformer base connections.
LUMINAIREA complete lighting unit.
MAGNETIC PARTICLE INSPECTIONA non-destructive method of detecting cracks and other discontinuities at or near the surface in ferromagnetic materials (ASTM E709).
MANDREL FORMEDThe manufacturing process used to produce round tapered tubes by forming steel coil around a mandrel.
MAST ARMThe horizontal member of a structure typically used to support luminaries, traffic signals or roadway signs.
MECHANICAL PROPERTIESThe properties that describe the way a material responds to forces that attempt to bend, break, twist, dent or scratch it.  Mechanical properties are the most important properties for fasteners.
MEDIUM-CARBON STEELA type of carbon steel that contains between 0.3% and 0.5% carbon.  Grade 5 fasteners are common medium-carbon steel fasteners.
MEGAPASCALThe metric unit of pressure.  Megapascal is abbreviated Mpa.
MILD STEELComparatively soft and easily worked steel capable of being extended or shaped.
MILL/MATERIAL CERTIFICATIONAn official document issued by the steel mill stating the physical and chemical properties of the material supplied.
MOMENTA force multiplied by the distance to the point of rotation. (See "Bending Moment")
MOMENT OF INERTIAPhysical property of a structural cross section used in the calculations of stresses and deflections. It is the summation of the products of element areas, multiplied by the square of their distance from a referenced line.
MOUNTING HEIGHTVertical distance to a particular part of a pole structure. (i.e., luminaire mounting height).  The height measured from ground level to the centerline position of the luminaire.  This height may include the rise of the luminaire arm and would subtract the burial length of an embedded pole.
NEMANational Electrical Manufacturers Association
NEMA BOXAn enclosure mounted to a pole used for breaker switches and terminal blocks. The name is derived from an enclosure being rated by the National Electrical Manufacturers Association.
NIPPLEExternally threaded steel fitting used for wiring access and attachment of controller cabinets, junction boxes or other related devices.
NONFERROUSA metal that does not contain iron.  Aluminum, copper, and zinc are nonferrous metals.
NON-THREADED FASTENERA type of fastener that does not contain threads.  Pins, retaining rings, and rivets are examples of non-threaded fasteners.
NUT COVERA decorative cast cover usually fastened to the pole covering the anchor bolt.
NUT HOLDERA small bracket usually welded to the inside of a pole, designed to hold a 0.5 in. square nut used for grounding purposes.
OBSTRUCTION LIGHTA light mounted on a structure to warn aircraft of its presence.
OCTAGONAL POLEA pole having an eight-sided cross section.
OFF-TORQUEThe force that is proportional to torque in the opposite manner.  An off-torque condition causes the fastener to rotate loose.
ONE-PIECE SLIPOVER BASEA one-piece shell base, which slips over the pole during installation.
OPTICONControl device acting as a switch upon sensing motion or light.
ORIENTATIONThe position of an appurtenance relative to the circumferential cross section of a pole/arm as measured in degrees from a reference point. (See also "Radial Index")
O-RINGA ring made from natural or synthetic rubber, used as an air-tight or water-tight seal.
OVERLOADINGA type of material failure that occurs when an excessive load is applied, which causes the material to yield or fracture.
OVERTURNING MOMENTBending moment at the pole base used for foundation analysis. (See also "Bending Moment")
OXIDATIONThe chemical reaction of a material when exposed to oxygen.
P.E.C.Photo Electric Cell (See also "Opticon")
P.S.I.Pounds per Square Inch
PAINTING SYSTEMA series of processes involved in producing a desired finish.
PANEL BOXSee "Controller Cabinet"
PARAPETA low retaining wall on a bridge or highway. Mounting poles on parapets usually requires special anchor bolt patterns.
PED POLEA pole designed to support pedestrian signal heads.
PEDESTAL POLEA term used to describe the short range of poles.  These poles are generally 4-5 inches in diameter and have a 6-20 foot mounting height.
PERMANENT DEFORMATIONThe stress that causes a material to lose its original shape and appearance.
PHYSICAL PROPERTIESThe properties that describe the way a material responds to external environment conditions, such as temperature, chemical exposure and electricity.  Corrosion resistance is the most important physical property for fasteners.
PIPEA hollow steel cylinder manufactured to a specific nominal inside diameter, wall thickness and yield strength.
PLANSThe portion of the contract document that depicts the project requirements by the use of drawings or illustrations.
POLEThe vertical member of a structure.
POLE TOP PLATEA steel plate mounted to the top of a pole.
POLYCARBONATEA lightweight thermoplastic that is used in the production of some traffic signal housings and back plates. Polycarbonate traffic signals have a high impact strength and are generally lighter in weight than a comparable aluminum traffic signal head.
POUNDS PER SQUARE INCHA unit of pressure that measures the amount of load pressure per inch.  Pounds per inch is abbreviated psi, or pounds per square inch.
POWDER COATAn electrostatically applied dry powder coating that is then oven cured for a smooth and durable finish.
PRELOADThe tension created in a fastener when it is first tightened. Preload must be greater than the external forces applied to the assembly to prevent joint failure.
PRODUCTION DRAWINGAn illustration showing all of the details and information necessary to manufacture the product.
PROJECTED AREAThe surface area subjected to wind pressures.
PROJECTIONLength of anchor bolt protruding beyond the top of a foundation.
PROOF LOADThe amount of stress that the fastener can withstand without experiencing deformation.  Proof load is often used interchangeably with yield strength.
PROPERTIESThe characteristics of a material that distinguish it from other materials.
PROTECTIVE COATINGA layer applied over metal that contains elements, which prevent the metal from damage.
RADIAL INDEXAn illustration showing the orientation of appurtenances. (See also "Orientation")
RAKEThe incline of a pole shaft from the vertical. A pole shaft is usually raked back to account for the deflection in the pole that will be caused by dead loads.
REBARDeformed steel reinforcing bar.
RECORD DRAWINGFormal drawing provided to customer showing final manufactured product.
RIV-NUTMetal fastener serving as the female threaded portion of a bolted connection. This device is a blind nut which is very comparable in function to a household molley. Primarily used for luminaire arm attachment.
ROCKWELL SCALEA method for testing a material's hardness that uses an indenter to test the material's resistance to deformation as a load is applied.
S.O. CHORDSun and oil resistant electrical connection.
SAFETY BELTComponent of pole climbing device strapped around a person's body and attached to the safety cable.
SAFETY CABLEComponent of climbing device fixed at both ends of the pole structure providing attachment for the safety belt.
SAGThe distance a wire or cable droops from its attachment point. Usually expressed as a percentage of the span length.
SBCStandard Building Code
SECTION MODULUSPhysical property of a structural cross section used in the calculation of stresses. The section modulus is the ratio of the moment of inertia to the farthest distance from the neutral axis.
SETBACKDistance from the roadway edge to the location of the pole.
SFBCSouth Florida Building Code
SHEAR FORCEForce within a member that acts perpendicular to the axis of the member.
SHEAR STRENGTHThe ability of a material to resist internal sliding.
SHEARINGThe cutting and separating of material through its cross section.
SHOE BASESee "Fixed Base"
SHOEBOXSlang term used for describing a rectangular shaped outdoor lighting fixture.
SIGN STRUCTUREStructure designed to support signs, signals or other devices. These structures may be of the cantilever type or the bridge type.
SIMPLEX CONNECTIONA bolted flange connection rigidly attaching an arm to a pole shaft.
SLEEVEAn additional layer of steel wrapped around a specific area of a pole shaft serving one of two purposes: 1) enhancing corrosion resistance on embedded type poles at ground level; and 2) adding to, reinforcing, or replacing a pole's structural characteristics.
SLIP BASE ASSEMBLYDevice used to connect the pole to the anchor bolts, designed to breakaway when the pole is impacted by a vehicle. The main purpose being to assure passenger safety.
SLIP FITTERA short piece of pipe/tube used as the internal portion of a connection.
SLIP-FIT CONNECTION (pole/arm splice)A type of connection between two tapered shafts. The top section is designed to fit over the top of the lower section a specified distance, creating a tight friction connection.
SLOPEAs pertaining to deflection: angular deviation from a chosen line (usually the center line of the pole or arm) expressed in degrees or in inches per foot.
SMASignal Mast Arm
SOCKET SCREWA type of capscrew with a round head and a hexagonal indentation for tightening purposes.
SPAN WIRE POLEA pole used to support wires or cables from which traffic signals or signs are suspended. (Also called "Strain Pole")
SPECIFICATIONSAn organized listing of requirements for materials, products, design or testing. Specifications can be published nationally (i.e., AASHTO, ASTM, etc.); locally (i.e., state, city, county, etc.); or per project.
SPINNING PROCESSManufacturing process in which a straight non-tapered tube is spun about the longitudinal axis while forming bars and/or forming wheels produce a desired taper or shape.
SPOKE ARMLuminaire mounting bracket designed with straight arms, with no upturn or upsweep from the point of attachment.
STATIC LOADA constant or non-varying load.
STEPSRemovable headed bolts fastened to pole shafts used for climbing.
STRAINChange in length of an object in one direction per unit of undisturbed length.
STRAIN POLESee "Span Wire Pole"
STRENGTHThe ability of a material to resist stress caused by forces attempting to break or deform the material.
STRESSThe internal force per unit area within a member, usually expressed in pounds per square inch (PSI).
STRESSThe applied force over a certain area that tends to deform an object or structure.
STRUCTURAL BASEA base welded to the shaft and contributes to the structural integrity of the pole.
STUDAn externally threaded fastener that is often threaded at both ends and can be used with a nut.  Unlike bolts, studs do not have a head.
SYNTHETICSomething that is produced artificially.  Synthetic materials include plastic and nylon.
TAMPER RESISTANT SCREWA screw with a specially designed head that requires a unique screw driver or wrench for removal or placement.
TAPERContinuous gradual reduction of a shaft's diameter along its length from base to top. Taper is usually expressed in inches of diameter per foot of length.
TAPPINGThe formation of an internal screw thread in a hole by means of a tap.
TEMPLATEA guide or pattern used for the proper placement of anchor bolts or drilled holes.
TENONShort length of pipe or tubing used to mount luminaries, signals or brackets.
TENSILE STRENGTHThe maximum stress a material can endure before it breaks.  Tensile strength is the most important property associated with threaded fasteners.
TENSION LOADA pulling force that is directed away from the object and attempts to stretch or elongate the object.
TETHERA second wire on a span wire pole used to hold the bottom of signals or signs in place when being acted upon by a wind force. The addition of this second wire increases the stress in the pole support.
THERMAL CONDUCTIVITYThe ability of a material to conduct heat.
THERMAL EXPANSIONThe tendency of a material to increase in size as it increases in temperature.
THREAD STRIPPINGA type of fastener failure that occurs when a fastener is over-tightened.  Thread stripping causes the fastener threads to appear deformed.
THREADED FASTENERA type of fastener that contains threads.  Bolts, screws, and nuts are examples of threaded fasteners.
TOLERANCEThe unwanted but acceptable deviation from a specified dimension.
TORQUEThe product of a force multiplied by the distance to the point of rotation causing a twisting action or twisting moment on a particular body. (See also "Torsional Moment")
TORQUEThe amount of force applied to tighten a bolt, screw or nut.
TORSION TESTA test that involves twisting an object to test a material's shear strength.
TORSIONAL LOADA force that is applied by clamping one end of an object and twisting the other.
TORSIONAL MOMENTAction of external forces causing twist in a structure. (See also "Torque")
TORSIONAL STRENGTHThe ability of the material to resist a torque that attempts to twist it off its axis.
TRACEABILITYThe ability to trace the history, application or location of an item using documentation.
TRANSFORMER BASESteel or aluminum box-type assembly placed under a pole for wiring access and originally used for housing ballast.  Now primarily used as a breakaway device (aluminum only).
TRANSMISSION POLEA pole structure designed to carry high voltage power lines over great distances.
TRUSS ARMArm style that incorporates two main supporting members with one or more vertical struts between them.  The number of vertical supports is determined by the load and length of the arm.  This type of arm is most commonly used for Luminaire pipe arms that exceed eight foot in length.  Truss arms range from 8' to 18' long.
TUBEGeneric term used for hollow steel shafts.
TURN OF THE NUT METHODA method described in the AISC Steel Construction Manual for the proper method of tightening nuts on bolts.
TURNKEYResponsibility of a single contractor or representative to supply and install materials completed and ready for operation for an entire project.
U-BOLTType of bolt that is shaped in the form of a "U" and threaded on both ends.
ULTIMATE TENSILE STRENGTHThe final amount of stress sustained in a tensile test at the exact moment the object ruptures.
ULTRA COATINGFinish coating system offered by Valmont that provides a maximum corrosion resistance finish and backed by a ten year warranty.
UPRIGHTSlang term referring to the vertical pipe portion of a sports lighting cage.
VEHICLE POLEA pole designed to support vehicular and/or ped signal heads.
VIBRATION DAMPERA device that is placed on or inside a pole or arm to reduce or prevent harmonic vibration caused by wind.
VIBRATION LOOSENINGA type of fastener failure that occurs in a bolted joint due to excessive motion, which causes the bolt to rotate loose.
VICKERS SCALEA method for testing a material's hardness that uses a pyramid-shaped diamond to exert pressure on the surface of a material for a standard length of time.  The diagonal of the indentation is measured under a microscope to determine the hardness value.
WASHERA flat disc with a hole through the center that is often used with threaded fasteners to ensure tightness of the joint.
WEDGE TENSILE TESTA procedure used to test tensile strength in which a washer with a beveled surface is placed under the head of a fastener causing a bending stress.
WIND LOADINGLive load pressures of wind acting on a structure.
WIND SPEEDVelocity of wind (MPH) noted either as a basic/isotach speed or as a gust/maximum velocity.
WIREWAY OPENINGAn opening that allows the passage of internal wiring to an externally mounted fixture usually contains a grommet.
WROUGHT ALLOYThe compound mixture of base elements which form a material whose physical and mechanical properties favor wrought (beaten into shape) manufacturing processes.
YIELDThe stress in a material at which plastic deformation occurs.
YIELD MOMENTThe moment in a pole or arm that will cause the member to yield.
YIELD STRENGTHThe maximum force that a material can withstand before it experiences permanent deformation.