Windshield and Auto Glass Glossary

TERM	DEFINITION
A Pillar	The part of the car body on the sides of the windshield, that helps support the roof.
Acoustic Interlayer	Glass having a thicker than normal vinyl laminate for noise reduction.
Acrylics	A non-crystaline thermoplastic with good weather resistance, shatter resistance and optical clarity; sometimes used for glazing.
Acute Area	The area of the windshield directly in front of the driver's eyes, beginning just above the steering wheel. It measures approximately 8 1/2 inches high by 11 inches wide. This area is used as the standard for the driver's critical vision area by most auto glass shops and insurance companies in the United States.
Adhesion	The clinging or sticking together of two surfaces. The ability of an adhesive to stick to a surface.
Adhesive	Any substance that is capable of bonding other substances together by surface attachment. In an auto glass replacement context, it is a high-strength polyurethane material unless otherwise specified.
Adhesive Failure	Adhesive failure indicated by the material's failing (pulling loose) at the surface of the substrate. Similar to "scotch" tape peeling off a plastic substrate.
Aftermarket	A term that refers to any car parts that were not made by the original manufacturer of the part.These may or may not meet the exact specifications of the manufacturer (in the case of windshields, the exact specs are often not available to the creators of aftermarket parts). See also OEM.
AGRSS	Automotive Glass Replacement Safety Standards. Safety standards widely accepted by the industry.
Air Quenching	Part of the process of tempering glass, when rapid cooling occurs by blowing air onto both surfaces uniformly and simultaneously.
Air Side	The upper surface of the glass, also referred to as score side.
Airbag	A passive restraint system that uses an explosive device to inflate a bag at a high rate of speed. The bag inflates with a gas and then quickly deflates when a vehicle occupant is thrown into it. It is mounted in the steering wheel on the driver's side of the vehicle and in the dashboard on the passenger's side. There are also airbags installed for side impact collisions. Some passenger-side airbags use the windshield to position the deploying bag.
Annealing	The controlled process of cooling glass after manufacturing to strengthen glass and make it less brittle.
Antenna	A conductor by which electromagnetic waves are sent out or received, consisting commonly of a wire or set of wires. In some late-model vehicles the radio antenna is incorporated into the windshield or the backlite.
Anti-Lacerative Glass	Glass that has a resilient layer (PVB) added to the inner surface. It prevents passengers from coming into contact with broken glass edges on the inner surface in the event of a collision.
Anti-theft	Vehicle glass that is made of laminated glass & tempered glass sandwiched together to help prevent smash & grab theft.
Auto Glass Repair	The act of repairing a break in a windshield or other laminated auto glass part, rather than replacing it. Auto glass repair is a permanent process that removes the air from the break and fills it with a curable, optically matched resin. Same as windshield repair.
Auto Replacement Glass	Abbreviated ARG. This is the industry term for aftermarket glass.
Autoclave	A large pressurized oven used in the glass industry to heat layers of polyvinyl plastics and glass to form laminated glass.
B Pillar	The part of the car body that supports the roof, that appears behind the A Piller. In most cars, this is the between the front and rear doors.
Bead	A sealant or adhesive compound after application in a joint, irrespective of the method of application, such as a urethane bead applied to a pinchweld. A bead looks like a ribbon of adhesive rather than a round drop of adhesive.
Belt Molding	A rubber molding between the inner and outer panels of a vehicle door through which the door glass is raised and lowered.
Bite	Amount of adhesive overlap between the pinchweld and windshield.
Block (setting)	A small piece of neoprene or other suitable material used to position the glass in the frame or opening.
Bug	The ANSI insignia on laminated and tempered glass.
Bullet-Resistant Glass	Glass that consists of multiple layers of laminated glass. It is designed to resist penetration from medium to super-power small arms and high-power rifles.
Bull's Eye	Damage to glass caused by a rock (or other object) that is circular, typically with a cone in the outer layer of the glass.
Butyl	An adhesive used in earlier model vehicles for glass retention. It is a petroleum product that requires no curing or hardening. Butyl is available in rolls of approximately 15 feet. Sometimes called "Butyl Tape Kit" or "Tape Kit." It is available in various thicknesses and shapes.
Butyl Rubber	A copolymer of isobutene and isoprene. As a sealant, it has low recovery and slow cure, but good tensile strength and elongation.
C Pillar	This term normally refers to the part of the car body on the sides of the rear windshield, which help support the roof of the car. However, some vehicles have more than 3 pillars on each side, in which case this would refer to the third set.
Caulk (noun)	A sealant with a relatively low movement capability.
Caulk (verb)	To fill the joints with a sealant.
Caulking	A resilient mastic compound often having a silicone, bituminous, or rubber base; used to seal cracks, fill joints, prevent leakage, and/or provide waterproofing.
Cell Cast	A method of manufacturing plastics, where molten plastic is poured between two sheets of glass and allowed to cure.
Channel	A piece of U-shaped metal lined with felt used to reduce glass breakage and noise, and to correct alignment of moveable glass parts.
Channel Tape	A cork and rubber composition material used to secure door glass and to fill channels.
Chip	Impact damage to laminated glass that does not penetrate the outer lite. Although glass is missing from the impact point, there is no trapped air in the damage.
Close-Cut Or Partial-Cut Installation	An installation method that leaves most of the existing adhesive bead/bed adhered to the metal frame and adds a small fresh bead of adhesive into which to set the glass. Some vehicle manufacturers do not recommend this procedure.
Coated Glass	Glass with a chemical film applied to one surface. The film can provide such enhanced performance characteristics as privacy, solar or mirror effects.
Combination Break	A break in a windshield involving more than two types of breaks.
Comprehensive	The type of insurance that covers most windshield damage in the United States, such as rocks being thrown up from the street.
Compress	The act of pressing together or to force into a smaller space.
Compression Gasket	A system that uses a soft gasket on one side of the glass and a firm, dense gasket called a wedge on the other.
Coolant	A liquid used to cool and lubricate glass while it is being cut or ground with a tool to prevent hot spots or fracturing of the glass.
Crack	An extended crack in a windshield from both sides of an impact point. There are several different kinds of cracks: Short crack: A crack on the windshield of 6 inches (15.24 cm) or less. Long crack: A crack on the windshield of more than 6 inches (15.24 cm).Edge crack: Any crack on the windshield that extends to an edge. Floating crack: Any crack on the windshield that does not extend to an edge. Stress crack: Any crack extending from an edge without an impact point.
Cure Time	The time required for a chemical or material to dry or set at a given temperature and humidity. Cure time varies with the type of material used and the thickness of the application. See Safe Drive Away Time.
Deductible	The amount of money that you have to pay when insurance covers part, but not all, of the cost of a repair or replacement. For example, if you have a $250 deductible, and the cost to replace a windshield is $400, you would pay $250 and the insurance company would pay $150. Note that many insurance companies will waive the deductible if you repair a windshield rather than replace it (so the insurance company would pay the entire cost); if you have that option, and your windshield has never been replaced before, you should take it.
Delamination	The failure of the bond between layers, as when windshield glass separates from the laminate, or when paint peels from the substrate beneath it.
Department of Transportation	See DOT.
Dessicant	An extremely porous crystalline substance used to absorb moisture from within the sealed air space of an insulating glass unit.
Diamond Cutters	Specially shaped diamond to score glass.
Ding	A term often used by the public to refer to a stone damage to a windshield.
Diversity Antenna	Combines the reception from 2 or more antennas on the vehicle. They work together to achieve superior radio reception. Usually appears as a thin brown or orange line inside the glass
DOT	Short for Department of Transportation. This is the U.S. Government agency that handles transportation of all types. See also NHTSA.
Dot Matrix Shade	The traditional gradient shade band in the laminate is replaced by a dot matrix frit across the top of the windshield. These little black dots are painted onto one of the glass surfaces.
Double Seal Units	Insulating glass with two materials used to form the seal of the glass.
Drop-Jaw Glass Pliers	Pliers used for breaking glass. They have a flat upper jaw and humped lower jaw.
Dry Glazing	A method of securing glass in a frame by use of a dry, preformed, resilient gasket without the use of a compound.
Edge Crack	Any crack that that extends to an edge of the windshield.
Encapsulated glass	A type of auto glass fabrication. Pre-assembled parts that contain hardware: moldings, fasteners, clips, or gaskets. Glass with a decorative molding around all or part of the perimeter. The encapsulation can also act as a channel guide. The molding (encapsulation) is actually part of the glass and can be removed only by cutting it off the glass.
Expansive Cement	An adhesive used to anchor glass railings into a base.
Fast Cure Urethane	An adhesive that can be used on windshields that cures quickly, allowing the car to be driven safely sooner.
Federal Motor Vehicle Safety Standards (FMVSS)	A series of standards required of the automobile manufacturers by the Federal Government. All new vehicle models must meet these standards before they are allowed to be sold in the United States.
Fiber Paddle	A tool with a tapered end made of plastic or fiberglass. It is used to loosen the bond between and to install a windshield into a gasket. It is one of the most commonly-used tools in gasket installations because it does not scratch paint and glass. Also called a fiber stick, bone, spoon and slip stick.
Filler Strip	A strip inserted into a rubber gasket after the glass is installed, forcing the gasket against the glass to form a seal and improve the grip. It is sometimes called locking a bead or spline.
Fire Windows	Fire endurance-rated glazing material.
Fire-Rated	A label given to a material after it has passed specific fire
Floater Crack	A crack that starts in the middle of the windshield (anywhere that is not within about 2" (5cm) of the edge of the windshield).
Floating Crack	Any crack on the windshield that does not extend to an edge. See also: Crack.
Flowering	A flower petal effect around the outer edge of a repair. This is caused by the laminate detaching from the outer layer of glass.
Frit	This is the painted black band around the perimeter of the windshield. The adhesive is underneath this band, so the band is able to help protect the adhesive from damage from the sun.
Full Strip Installation	An installation method whereby the technician removes the existing bed/bead of adhesive from the vehicle frame. Approximately 1-2 mm of old adhesive remains. The technician applies new/fresh adhesive on top, then sets the glass into the fresh adhesive.
Gasket	A seal, usually of rubber, that holds a piece of auto glass to the vehicle body. There are various sizes and shapes of glass part gaskets, depending on vehicle design.
Half Moon	Damage to a windshield that has a half-circle separation around the impact point. It is similar to a bull's eye.
Hardened	Glass that undergoes a process to make it more resistant to breaking that regular glass. See also Tempered Glass.
Heated Urethane	A type of adhesive that is heated to a prescribed temperature before application. The heat "pre-cures" the adhesive for faster release of the vehicle.
Heated Wiper Park Area	Windshield contains heater grids across the lower part of the glass where the wipers rest. Usually visible as brown or grey lines running horizontally at the base of the windshield.
Hook Tool	A tool designed for use in installing a glass part into a gasket. Sometimes known as a cotter pin puller.
HUD	Heads up display. Some of your vehicle's key instrumentation is flashed up onto the bottom of the windshield. This allows drivers to check speed, etc. without having to take their eyes off of the road.
Impact	This is the most common break. It occurs when an object hits the windshield.
Impact Point	The location on the windshield where an object hit it that caused damage. Usually a small piece of glass chips off in this location.
Impact Site	The actual location on the outside layer of glass, where it was struck by an object (usually a stone). Typically a small piece of glass is missing.
Infrared	A term used to describe Solar Coated glass.
Lami	Another name for laminated glass (see laminated glass).
Laminate	Vinyl inner layer of laminated glass.
Laminated Glass	This is actually two (or more) pieces of glass that are held together with a piece of plastic. If the glass breaks, it usually sticks to the plastic, making it less likely to injure people. The plastic can also help prevent occupants of the vehicle from being thrown out of the car.
Laser Deletion Area	a solar coated glass that has a small area without coating to allow lasers to work through the glass.
Legs	Short cracks that emanate from a break.
Light Sensor	A sensor usually located on the windshield that senses the absence of light and turns the headlights on.
Light Transmittance	The amount of light that passes through glass. For most car windows, this is required to be 70% or more.
Lite	Regarding a windshield, this refers to a single layer of glass (as opposed to the whole windshield, which consists of two pieces of glass separated by a layer of plastic).
Locator Tapes	Tapes used to align the glass to the vehicle body during a dry set of the glass. (See Dry Set.)
Long Crack	A crack that is over about 6" (15cm) long, which many windshield repair methods are unable to fix.
Low E Glass	Low emissivity glass; a type of reflective glass that is popular in residential and office applications.
Manpower	The total number of people available for work or service.
Mobile Unit	A vehicle, usually a van or light truck, properly equipped with repair and safety equipment and tools, driven to an auto glass repair customer's home or place of business. Glass repairs are made from the vehicle.
Molding or Chrome Release Tool	Tool used to remove molding clips from a windshield or back lite.
National Highway Traffic Safety Administration	This is a subsidiary of the U.S. Department of Transportation, that is responsible for the safety of cars. Among other things, they are responsible for the FMVSS series of laws that cover the safety of vehicles, including windshields.
Negligent	Habitually guilty of neglect, extremely careless or casual.
Neoprene	A synthetic rubber having physical properties closely resembling those of natural rubber but not requiring sulphur for vulcanization. Extremely good weather resistance (both heat and cold) with ultraviolet stability.
NGA	National Glass Association. It is an association of companies involved in glass (automotive and otherwise).
OEM	Short for Original Equipment Manufacturer. This is a car part that either was made by the manufacturer of the car, or was ordered by the manufacturer of the car. Note that insurance companies in some U.S. states are allowed to use used parts, which should of course not be confused with new OEM parts. See also Aftermarket.
One-Part Urethane	An adhesive used in auto glass replacement that has only one component.
Opacifier	A material, either film or liquid, that is applied to the back of a piece of glass to act as a light shield.
Open Time	The time interval between the application of an adhesive and when it becomes no longer workable.
Pinchweld	A type of metal weld joint. In the auto glass industry, the pinchweld is the part of the vehicle frame where the glass adheres.
Pit	The area where glass is missing, after a rock or other item impacts the car.
Plastic Interlayer	The term for the piece of plastic that is between the inner and outer layers of glass on a windshield.
Polysulfide	An adhesive used to bond auto glass to vehicles prior to the advent of urethane.
Polyvinyl Butyral (PVB)	A vinyl film used in laminated glass.
Polyvinyl Butyrate	See PVB.
Preformed Gaskets	Glazing gaskets manufactured to window openings, usually made of rubber or urethane.
Quarter Glass	A term used for triangular passenger or driver windows in a car, that typically cannot be opened, that are usually adjacent to the rectangular part of the window that can be opened.
Rain Sensor	A sensor usually located near the windshield's rear view mirror that senses rain and activates the wipers.
Resin Laminating	A process used to laminate curved glass and other specialized, limited batch applications.
Reveal Molding	Chrome or plastic molding which fits over and covers the edges of the windshield and back glass.
Rubber Blocks or Spacers	Small rubber blocks/spacers, used by some manufacturers, to separate the glass from the metal frame.
Safe Drive Away Time	The amount of time that you need to wait after a windshield is replaced before it can safely be driven. This time depends on the adhesive used, and other factors such as humidity.
Safety Glass	Glass that is manufactured in a way to make it safer than normal glass. This usually involves either making the glass harder (making it more difficult to break, and when broken, the pieces are less sharp), or by laminating it. See also Laminated Glass, Tempered Glass.
Salvage Part	A used part that is obtained from a vehicle that is no longer functional (such as one that has been in an accident, flood, or otherwise would cost too much to fix). In many states, it is legal for insurance companies to use used parts.
Setting Block	A small piece of neoprene or other suitable material that positions the glass in the frame or opening. An automotive part on which the glass rests in place.
Shaded Glass	Laminated glass in which a dark color has been added to the top section of the inner vinyl layer to improve driver visibility in glare. The color typically becomes lighter as the tint travels down the glass.
Short Crack	This term typically refers to a crack that is short enough to be repaired by the more common windshield repair methods, which is about 6 inches (15cm) or less.
Side-Lite	Passenger car side windows.
Solar Coated	During the manufacturing process, the inside surface of the outer layer of Non-Solar glass is coated with UV reflective film before the inner layer (PVB) is sandwiched between the outer and inner layers of glass.
Star Break	Multiple small cracks coming out from the point where a rock or other item hit the windshield.
Stone Break	A break on the outer layer of a laminated windshield. Typical stone breaks are star breaks, bullseyes or combination breaks.
Stress Crack	A crack that occurs without anything hitting the windshield, typically due to a large variation in the temperature . It almost always starts at the edge of the windshield.
Tape Glazing	Installing glass or products with butyl tape.
Tempered Glass	A type of glass that is stronger than normal, and designed to shatter into small pieces (rather than large, sharp pieces) if broken. Tempered glass is made by heating it and then quickly cooling it.
Tempering	Strengthening glass with heat.
Tinted Glass	Glass that blocks a noticeable amount of light. This reduces glare, and helps absorb heat. However, federal U.S. and many local laws require a certain amount of visibility. See also Light Transmittance.
Translucent	Permitting light to come through but diffusing it so that objects on the other side appear vague, distorted or imperfect.
Transparent	Permitting light to come through without distortions so that objects on the other side can be seen clearly.
Trim Ring	Ring of molded plastic or bowed metal which covers the headliner and secures the sunroof to a vehicle.
Twist	A crack which occurs when the windshield is twisted, either by flexing in the vehicle frame or because of improper mounting. It can be helped along if the windshield has a nick in the edge.
Unleaded Frit	A painted band around the perimeter of the glass applied with unleaded paint. It requires special preparation before bonding.
Urethane	An adhesive material that is used to bond a windshield to the car. Also, a family of polymers ranging from rubbery to brittle. Usually formed by the reaction of a diisocyanate with a hydroxyl; also called polyurethane.
Urethane Breakdown	Results when urethane is exposed to ultra-violet light. Urethane breakdown appears as a chalky black powder on the surface of the hardened adhesive.
Vacuum Cup	A tool used for picking up glass.
Wet Glazing	A method of sealing glass in a frame by use of sealants rather than dry-glazing gaskets.
Windshield	The glass that is used on the front of a car. It is made of laminated glass, and helps support the weight of the car in the event of an accident.
Windshield Repair	The act of repairing a break in a windshield, or other laminated auto glass part, rather than replacing it. Windshield repair is a permanent process that removes the air from the break and fills it with a curable, optically matched resin. Same as auto glass repair.
Wiper Sweep	The area of the windshield that windshield wipers clean.
Wired Glass	Made by feeding a welded wire net of a particular design into the molten glass just before it enters the roller. The wire holds the lite in the sash in case it shatters.