| AC |
Alternating current. Electricity that flows in opposite directions at different times. AC switches direction 60 times per second, or 60 hertz, in the U.S. |
| alternating current |
AC. Electricity that flows in opposite directions at different times. Alternating current switches direction 60 times per second, or 60 hertz, in the U.S. |
| ammeters |
A device that measures current in an electrical circuit. Ammeters are sometimes built in to welding power sources. |
| amperes |
A. The unit used to measure current or amperage. Amperes are also called amps. |
| arc |
The area in which electricity transfers from the electrode to the workpiece. The arc generates the heat that melts the base metals. |
| arc blow |
A condition that occurs when the arc does not follow its intended path from the electrode to the workpiece. Arc blow can cause poor quality weld beads. |
| arc length |
The distance that electricity must travel from the tip of the electrode to the weld puddle. Arc length may depend on voltage. |
| arc welding |
A fusion welding process that uses electricity to generate the heat needed to melt base and filler metals. Arc welding is the most commonly used welding process. |
| atoms |
A tiny particle that makes up all materials. Atoms are the smallest distinguishable units of an element that retain the element's characteristics. |
| base metals |
A metal to be welded to form a joint. Base metals' characteristics can greatly influence the strength of the final joint. |
| beads |
The end product of a joint that has been welded. Bead formation depends on the movement of the electrode. |
| CC |
Constant current. Electrical power in which current varies only slightly with changes in voltage. CC power is often used in shielded metal arc welding and gas tungsten arc welding. |
| circuit breakers |
A device that detects excess current to prevent overheating in a circuit. A circuit breaker often contains a bimetallic strip that bends and trips a switch to open a circuit. |
| circuits |
A controlled path through which electricity flows. Circuits consist of a source, path, load, and control. |
| compressed air |
Air that has been forced into a small space at high pressure. Compressed air is often used to clean electronics. |
| conductor |
A material that allows for the flow of electricity. Conductors are typically metals. |
| constant current |
CC. Electrical power in which current varies only slightly with changes in voltage. Constant current power is often used in shielded metal arc welding and gas tungsten arc welding. |
| constant voltage |
CV. Electrical power in which voltage varies only slightly with changes in current. Constant voltage power is often used for gas metal arc welding and flux-cored arc welding. |
| consumable electrode |
A device that conducts electricity from the contact tip of the welding gun to the arc and melts into the weld as a filler metal. Consumable electrodes are used in GMAW and FCAW. |
| current |
I. The amount of electricity flowing in a circuit. Current is measured in amperes. |
| current output |
The maximum amount of current that a given power source can provide. Current output helps determine how much heat a power source can generate. |
| CV |
Constant voltage. Electrical power in which voltage varies only slightly with changes in current. CV power is often used for gas metal arc welding and flux-cored arc welding. |
| DC |
Direct current. Electricity that flows in one direction. DC is typically used for GMAW and FCAW. |
| DC electrode negative |
DCEN. Current that always flows in one continuous direction with straight polarity. With DC electrode negative polarity, electricity flows from the negative electrode to the positive workpiece. |
| DC electrode positive |
DCEP. Current that always flows in one continuous direction with reverse polarity. With DC electrode positive polarity, electricity flows from the negative workpiece to the positive electrode. |
| DCEN |
DC electrode negative. Current that always flows in one continuous direction with straight polarity. With DC electrode negative polarity, electricity flows from the negative electrode to the positive workpiece. |
| DCEP |
DC electrode positive. Current that always flows in one continuous direction with reverse polarity. With DC electrode positive polarity, electricity flows from the negative workpiece to the positive electrode. |
| deposition rates |
The rate at which filler metal melts off the electrode into the weld puddle. Deposition rates can be measured in pounds per hour or in grams per minute. |
| direct current |
DC. Electricity that flows in one direction. Direct current is typically used for GMAW and FCAW. |
| directly proportional |
A relationship in which one number increases or decreases at the same rate and in the same ratio as another number. Directly proportional is the opposite of inversely proportional. |
| duty cycle |
The amount of time in a ten-minute period that an electrical device can operate without overheating. Duty cycles are given as a percentage of the ten-minute period. |
| electric shocks |
The flow of electricity through the body. Electric shock can be fatal. |
| electrical box |
A metal cabinet in a building where power from the electrical distribution system enters and is distributed throughout the building. The electrical box connects to every circuit and device in the building. |
| electrical burn |
A burn caused by the flow of electrical current through tissue or bone. Electrical burns may occur when handling wiring or electrical equipment that has been improperly maintained. |
| electricity |
A form of energy created by the movement of electrons. Electricity can be converted into light, heat, or motion. |
| electrode |
A device that conducts electricity to the arc in arc welding. Electrodes may also serve as filler metal. |
| electrode cable |
The path used in arc welding to conduct electricity between the power source and the electrode. The electrode cable must be in good condition and installed correctly to prevent injury. |
| electrode holders |
An insulated handle that clamps onto an electrode. The electrode holder must be dry and in good condition. |
| electromotive force |
The electrical force or pressure that causes current to flow in a circuit. Electromotive force is also called voltage. |
| electrons |
A negatively charged particle that orbits the nucleus of an atom. Electrons flowing between atoms creates electricity. |
| energy efficient |
Having an energy output that is close to the total energy supplied. Energy efficient devices do work using smaller amounts of electricity, which costs less. |
| faults |
A dangerous electrical condition that prevents current from completing its circuited as intended. Electrical faults include short circuits and open circuits. |
| FCAW |
Flux-cored arc welding. An arc welding process that uses a continuously fed consumable electrode that contains flux at its core. FCAW is either a semi-automatic or automatic process. |
| filler metal |
Metal deposited into the weld joint in fusion welding. Filler metal adds to the strength and mass of the welded joint. |
| flat position |
The welding position in which the electrode is positioned directly above the joint. Flat-position welding situates the face of the weld horizontally. |
| flux-cored arc welding |
FCAW. An arc welding process that uses a continuously fed consumable electrode that contains flux at its core. Flux-cored arc welding is either a semi-automatic or automatic process. |
| formula |
A general fact or principle that is expressed mathematically. Formulas represent known equations using letters, numbers, and/or symbols. |
| gas metal arc welding |
GMAW. An arc welding process in which a bare wire electrode and inert shielding gas are fed to the weld through a welding gun. Gas metal arc welding is also referred to as MIG or MAG welding. |
| gas tungsten arc welding |
GTAW. A very precise arc welding process that uses a nonconsumable tungsten electrode. Gas tungsten arc welding is also referred to as TIG welding. |
| GMAW |
Gas metal arc welding. An arc welding process in which a bare wire electrode and inert shielding gas are fed to the weld through a welding gun. GMAW is also referred to as MIG or MAG welding. |
| grounding |
A means of providing a safe alternate return path for current that automatically disconnects power if a fault prevents current from flowing like normal. Grounding protects the electrical system and substantially reduces the risk of electric shock. |
| grounding conductor |
The wire that provides a low-resistance path to ground for fault currents. Grounding conductors are usually bare copper or covered with green insulation. |
| grounding pin |
The longest metal prong of a typical electrical plug. The grounding pin connects to a grounding conductor in the power system when plugged into an outlet. |
| heat distortion |
An undesirable physical change in a material due to excessive temperature changes. Heat distortion may be caused by excessive current. |
| hot wire |
The wire that provides power to an electrical device or load. The hot wire is usually covered with black insulation. |
| incomplete fusion |
The lack of complete integration between the weld metal and base metal or adjoining weld beads. Incomplete fusion can create gaps, which may lead to cracks and joint failure. |
| insulation |
Material that resists the flow of electricity. Insulation can prevent electric shock when used properly. |
| insulators |
A material that resists the flow of electricity. Insulators include rubber and plastic. |
| inversely proportional |
A relationship in which one number either increases as another number decreases or decreases as another number increases. Inversely proportional is the opposite of directly proportional. |
| inverter |
An energy-efficient welding power source. Inverters are smaller than traditional power sources, but they have more electrical power. |
| load |
A device in a circuit that converts electricity into another form of energy, such as heat, light, or motion. The load in an arc welding circuit is the arc. |
| low-carbon steel |
A carbon steel that contains less than 0.30% carbon. Low-carbon steel is the most commonly welded metal. |
| magnetic field |
The area in and around an energized conductor in which a magnetic force exists. Magnetic fields exhibit the powers of attraction and repulsion. |
| negative |
An electric charge with a surplus of electrons. A negative charge is symbolized by a minus sign (-). |
| neutral wire |
The wire that conducts power back to its source and completes the circuit. The neutral wire is usually covered with white insulation. |
| neutrons |
A particle that has no charge. Neutrons are located in the nucleus of an atom. |
| nonferrous |
Metal that does not contain iron. Nonferrous metals are more difficult to weld than ferrous metals. |
| Ohm’s Law |
The universal truth that describes the relationship between voltage, current, and resistance. Ohm's Law states that one volt equals one amp times one ohm. |
| ohms |
Ω. The unit used to measure electrical resistance. One ohm is equal to one amp divided by one volt. |
| out-of-position |
Any welding position that is not classified or categorized. Out-of-position welding often uses electrodes that have smaller diameters to prevent spillage. |
| overhead position |
The welding position in which welding that is performed from the underside of a joint. Overhead-position welding requires extra safety precautions. |
| path |
A conductor that directs electricity in a circuit. The path used for welding is often copper wire. |
| penetration |
The depth to which the arc heat can melt the joint below the surface of the base metals. Penetration partially depends on the amount of current. |
| personal protective equipment |
PPE. Safety equipment that workers wear or use to prevent injury in the workplace. Personal protective equipment includes welding helmets, long gloves, and safety glasses. |
| polarity |
Having two oppositely charged poles, one positive and one negative. Polarity determines the direction in which current flows. |
| pole |
One end of a magnet or axis. Poles are either negative or positive. |
| porosity |
The appearance of tiny holes on a weld bead as a result of trapped gas bubbles. Porosity can weaken a weld. |
| positive |
An electric charge with a shortage of electrons. A positive charge is symbolized by a plus sign (+). |
| power source |
The device that provides the electricity needed to perform arc welding. The power source is energized by the input voltage supply. |
| proportional |
Having a constant ratio or relationship. Proportional values change in order to maintain the same ratio. |
| protons |
A positively charged particle. Protons are located in the nucleus of an atom. |
| reactor |
A device used in an electrical circuit to stabilize and increase the current of electrical power. Reactors adjust current to suitable levels for arc welding. |
| rectifier |
A device used in an electrical circuit to convert AC power to DC power. Rectifiers allow electrical current to flow in only one direction. |
| resistance |
R. The opposition to electrical current flow. Resistance is measured in ohms (Ω). |
| shielded metal arc welding |
SMAW. An arc welding process that uses a flux-coated rod. Shielded metal arc welding is also referred to as manual or stick welding. |
| short circuiting |
The condition in which current takes a shorter, unintended path between two conductors. Short circuiting causes excess current flow. |
| slag |
Cooled flux that forms on top of the weld bead and must be chipped off. Slag occurs with welding processes that use flux. |
| source |
The device that provides electrical power to a circuit. The source in an arc welding circuit is the power source. |
| spatter |
Liquid metal droplets expelled from the welding process. Spatter can leave undesirable particles of metal on a workpiece surface. |
| thermal contact burns |
A burn caused by fire or extreme heat. Thermal contact burns can be caused by faulty electrical equipment. |
| torches |
A tool used to generate the flame or arc for welding. Torches hold the electrode for arc welding. |
| transformer |
A device used in an electrical circuit to reduce the voltage of incoming electrical power. Transformers lower the voltage to suitable levels for arc welding. |
| travel speeds |
The rate at which an electrode moves along a joint to make a weld. Travel speed determines the size of the weld bead. |
| trip |
To automatically open a circuit to prevent damage and injury. Tripped circuit breakers indicate problems in electrical circuits. |
| undercut |
A groove melted into the base metal at the weld toe or root that is left unfilled by weld metal. Undercut concentrates stress on the weld and can weaken it. |
| vaporize |
To transform into a gas. Vaporization may occur due to the application of heat. |
| voltage |
E. The electrical force or pressure that causes current to flow in a circuit. Voltage is also called electromotive force and is measured in volts. |
| voltmeters |
A device that measures the voltage in an electrical circuit. Voltmeters are sometimes built in to welding power sources. |
| volts |
V. The unit used to measure voltage. Volts indicate the electromotive force or voltage. |
| weld puddle |
The small area of molten metal that forms during welding. Weld puddles are also called weld pools, molten pools, and molten puddles. |
| welding gun |
A hand-held welding instrument that conducts electricity, guides the electrode, and, in some cases, releases shielding gas. Welding guns are used in some semi-automatic welding processes. |
| wire feed speed |
WFS. The rate at which the wire electrode is fed through the welding gun. Wire feed speed is measured in inches per minute or millimeters per minute. |
| work |
The result of a force applied to an object and the distance through which the force is applied. Work is equal to force multiplied by distance. |
| work cable |
The path used in arc welding to conduct electricity between the power source and the workpiece. The work cable must be in good condition and installed correctly to prevent injury. |
| workpiece |
The part being welded. A workpiece consists of the base metals in a welding operation. |