Introduction to FCAW 261

"Introduction to FCAW" provides a comprehensive overview of the flux-cored arc welding (FCAW) process and its equipment. FCAW is a semi-automatic or automatic process that is divided into self-shielded flux-cored arc welding (FCAW-S) and gas-shielded flux-cored arc welding (FCAW-G). Both FCAW-S and FCAW-G use a consumable, tubular electrode that is filled with flux-materials. FCAW equipment includes a constant voltage power source, wire electrode, wire feeder, welding gun, and, if appropriate, a shielding gas.

Understanding the basic theory and process of FCAW is essential to using it successfully. After taking this class, users will be familiar with FCAW equipment and be able to distinguish between different methods and materials. Users will also be able to identify the performance characteristics, operating requirements, and finished weld properties of FCAW electrodes. This information provides the foundation necessary to perform FCAW successfully and safely.

Class Details

Class Name:
Introduction to FCAW 261
Description:
"Introduction to FCAW" provides a comprehensive overview of the flux-cored arc welding (FCAW) process and its equipment. FCAW is a semi-automatic or automatic process that is divided into self-shielded flux-cored arc welding (FCAW-S) and gas-shielded flux-cored arc welding (FCAW-G). Both FCAW-S and FCAW-G use a consumable, tubular electrode that is filled with flux-materials. FCAW equipment includes a constant voltage power source, wire electrode, wire feeder, welding gun, and, if appropriate, a shielding gas.

Understanding the basic theory and process of FCAW is essential to using it successfully. After taking this class, users will be familiar with FCAW equipment and be able to distinguish between different methods and materials. Users will also be able to identify the performance characteristics, operating requirements, and finished weld properties of FCAW electrodes. This information provides the foundation necessary to perform FCAW successfully and safely.
Version:
2.0
Difficulty:
Intermediate
Number of Lessons:
23
Related 1.0 Classes:
What Is Arc Welding? 110, Arc Welding Processes 120, Electrical Power for Arc Welding 140, FCAW Applications 230, Arc Welding Power Sources 260

Class Outline

  • Arc Welding
  • Flux-Cored Arc Welding
  • Self-Shielded FCAW
  • Self-Shielded FCAW: Advantages and Disadvantages
  • Gas-Shielded FCAW
  • Gas-Shielded FCAW: Advantages and Disadvantages
  • FCAW Basics Review
  • FCAW Electrodes
  • FCAW Electrodes: Classifications
  • FCAW Electrodes: Reading AWS Labels
  • FCAW Electrodes: Flux Materials
  • FCAW Electrodes: Fluxing Reactions
  • FCAW Electrodes: Storage and Handling
  • FCAW Electrode Review
  • FCAW Equipment
  • FCAW Equipment: Self-Shielded Guns
  • FCAW Equipment: Gas-Shielded Guns
  • FCAW Equipment Review
  • FCAW Power Sources: Constant Voltage
  • FCAW Power Sources: Direct Current and Polarity
  • FCAW Power Sources: Categories of Welding Machines
  • FCAW Power Source Review
  • FCAW Safety

Objectives

  • Describe arc welding.
  • Define flux-cored arc welding.
  • Describe self-shielded FCAW.
  • Identify the advantages and disadvantages of FCAW-S.
  • Describe gas-shielded FCAW.
  • Identify the advantages and disadvantages of FCAW-G.
  • Describe FCAW electrodes.
  • Identify the AWS classification of FCAW electrodes.
  • Identify the purposes an FCAW electrode's flux material serve.
  • Describe storage and handling considerations for FCAW electrodes.
  • Identify common equipment used in flux-cored arc welding.
  • Describe the characteristics of self-shielded FCAW guns.
  • Describe the characteristics of gas-shielded FCAW guns.
  • Describe constant voltage.
  • Describe polarity and its effects on FCAW welding.
  • List the categories of power sources appropriate for use in FCAW processes.
  • Identify the safety precautions that should be observed during flux-cored arc welding.

Job Roles

Certifications

Glossary

Vocabulary Term Definition
AC Alternating current. Current that reverses direction at regularly recurring intervals of time. In the U.S., AC alternates 60 times per second, or 60 hertz.
air-cooled gun A FCAW-S or FCAW-G welding gun that is designed to operate at its rated amperages without requiring a water-cooling system. Air-cooled guns are intended for lower duty cycle applications and are more practical for use in field welding.
alloying elements A material that is intentionally added to a weld in order to change its properties. Alloying elements can improve the strength, ductility, hardness, and toughness of a finished weld.
American Welding Society AWS. The non-profit organization that regulates the industrial standards for welding. AWS also promotes the welding industry in the United States.
amperage A measurement of current. FCAW amperage is determined by the speed in which the electrode is fed through the welding gun.
arc stability The process of controlling a welding arc in an even and predictable manner. Arc stability is essential during the welding process.
arc welding A joining process that uses an electric arc to melt metals and fuse them together permanently. Arc welding processes include stick metal arc welding, shielded metal arc welding, gas metal arc welding, and flux-cored arc welding.
argon An inert gas commonly mixed with carbon dioxide for use as a shielding gas. Argon is much heavier than air, so it effectively shields the weld area.
automatic process A type of welding process in which a computer or a robot controls both the welding equipment and the weld variables. In an automatic process, the welder is responsible for setting and controlling the specialized settings for the computer or robot.
AWS American Welding Society. The non-profit organization that regulates the industrial standards for welding. AWS also promotes the welding industry in the United States.
base metal One of the two or more metals to be fused by welding or other joining methods. The base metal and its properties influence the type of welding and the type of electrode that should be used.
carbon dioxide CO₂. An active gas that is heavy, colorless, and odorless. Carbon dioxide is commonly used as a shielding gas.
carbon steels A common metal group that is an alloy of iron and carbon. The amount of carbon in a carbon steel affects its strength, ductility, and malleability.
chemical composition The type, amount, and arrangement of atoms that, combined, compose a whole material or substance. Chemical composition can be altered whenever a change occurs at the atomic level.
chemical properties The properties that describe a material's ability to withstand deterioration by solvents, chemicals, or water on the chemical level. An example of a chemical property is a material's ability to resist corrosion.
circuit A completely enclosed path that contains an electrical current. In welding, a circuit is also known as a welding circuit.
climate-controlled environment An environment in which the temperature and humidity are strictly moderated. Climate-controlled environments are ideal for storing FCAW electrodes.
combustible A material that can quickly catch fire if it comes in contact with sparks or fire. Combustibles must never be present in a weld area.
composite An electrode made of more than one metal. Composite electrodes are identified with a "C" in the AWS electrode classification system.
constant voltage CV. An amount of electricity from a welding power source that varies only slightly with significant changes in current. Constant voltage is used in FCAW processes.
consumable electrode An electrode that conducts electricity to the arc but also melts into the weld as a filler metal. Some consumable electrodes may also provide shielding that protects the arc and weld puddle.
contact tip The device located inside the welding gun that conducts electricity to the electrode and directs the wire electrode into the weld joint. The contact tip is usually made of copper.
contaminants Any foreign substance that may cause a loss of efficiency or a breakdown. Contaminants in welds include oxygen and nitrogen.
contamination The presence of damaging foreign materials such as dirt, moisture, or oil. Contamination will damage welding electrodes and compromise weld quality.
copper A reddish metal that is very ductile, thermally and electrically conductive, and corrosion resistant. Copper is used to make the contact tips of welding guns.
copper alloy A metal consisting of a mixture of copper and two or more other elements. Common copper alloys include aluminum-silicon-copper-magnesium and zinc-aluminum-copper-magnesium.
core The inner part of an electrode that is surrounded by an outer metal sheath. The core of FCAW electrodes contains flux materials.
corrosion resistance The ability of a material to resist deterioration and chemical breakdown due to surface exposure in a particular environment. Corrosion resistance is an important physical property of finished welds.
current The rate and amount of electrical flow, which is measured in amperage. A continuous current is required in arc welding in order to maintain the electric arc.
DC Direct current. Current that flows in one continuous direction. Direct current is required in several common welding processes such as GMAW and FCAW.
denitrifiers A material that removes nitrogen from the molten weld puddle and arc. Denitrifiers prevent nitrogen from ruining a weld bead.
density The amount of material within a specific volume. Objects with greater density have a relatively large amount of weight compared to the amount of physical space they occupy.
deoxidizers A material that removes oxygen from the molten weld puddle and arc. Deoxidizers prevent oxygen from ruining a weld bead.
deposition rate The rate at which an electrode melts into the molten weld puddle to form a weld. The deposition rate can be measured in pounds per hour (lb./hr) or in grams per minute (g/min).
designators A letter or a number used within the AWS classification system that specifies an electrode's characteristics and properties. Designators can be either mandatory or optional.
diameter The distance from one edge of a circle to the opposite edge that passes through the center. Round or cylindrical features require diameter measurements.
diffusible hydrogen designator A letter and number used in the AWS classification system that specifies the maximum amount of hydrogen present per 100 grams of weld metal. The diffusible hydrogen designator is a supplemental designator.
direct current DC. Current that flows in one continuous direction. Direct current is required in several common welding processes such as GMAW and FCAW.
direct current electrode negative DCEN. The arrangement of direct current arc welding cables and leads in which the electrode is the negative pole and the workpiece is the positive pole of the welding arc. Direct current electrode negative is sometimes called straight polarity.
direct current electrode positive DCEP. The arrangement of direct current arc welding cables and leads in which the electrode is the positive pole and the workpiece is the negative pole of the welding arc. Direct current electrode positive is sometimes called reverse polarity.
directly proportional A constant relationship between two values. If value A increases, value B also increases, and if value A decreases, then value B also decreases.
dirty steels Steels with surfaces that include surface contaminants. Dirty steel includes workpieces with rusted surfaces.
discontinuity An irregularity in the specified and expected composition of a weld. A discontinuity is not always a defect.
drawing dies Tools used to form wire or metal to a specified shape. Drawing dies reduce an FCAW electrode's diameter and compress its core materials during fabrication.
drive roll A set of wheels that facilitates feeding through a wire feeder. Drive rolls are specially designed for various types and sizes of electrodes and can be either smooth or knurled.
dual-shield welding A type of welding process that uses a flux-filled tubular wire electrode along with an external shielding gas. Dual-shield welding is also called gas-shielded FCAW or FCAW-G.
duty cycle The amount of time in a ten-minute period that an electrical device can perform work without overheating. If a device has a 30% duty cycle, it can operate for three consecutive minutes and must rest for seven.
efficiency rates The percentage of welding electrode that is used in the weld puddle. A higher efficiency rate indicates a lower amount of electrode lost due to spatter or wasted as unusable stubs.
electric arc The area in which electricity jumps from an electrode to a conductor to produce extreme heat and light. Electric arcs are used in welding and in some types of industrial furnaces.
electrode diameters A measurement of the thickness of the electrode. Electrode diameter can affect productivity.
electrode extension The distance from the end of the contact tip to the end of the electrode. Electrode extension is also called electrical stickout.
electrode liner The insulated coil-steel wire lining that surrounds the wire electrode and supports it from the wire feeder to the contact tip. Electrode liners can be either fixed or replaceable.
energy efficient A characteristic of power sources that signifies good use of electricity. Energy efficient devices do work using smaller amounts of electricity, which costs less.
engine-drive A welding machine that has no need for a transformer. Engine-drives are sometimes called choppers.
fabricated Constructed from various raw materials by a process that forms, reshapes, and assembles. Fabrication processes are usually more complicated than manufacturing processes.
FCAW-G Gas-shielded flux-cored arc welding. A type of FCAW process that uses a flux-filled tubular wire electrode along with an external shielding gas. FCAW-G provides the weld area with double shielding protection.
FCAW-S Self-shielded flux-cored arc welding. A type of FCAW process that uses a tubular wire electrode filled with fluxing agents that completely shield the weld area. In FCAW-S, no external shielding gas is needed.
feed rate The speed at which an electrode moves from its spool through the welding gun. In FCAW, the electrode feed rate determines the amperage.
ferrous metals A metal that contains iron. Ferrous metals are the most common type of welded metal.
filler metal Metal deposited into the weld that often adds strength and mass to the welded joint. In some arc welding processes, the electrode provides the filler metal.
fire extinguisher A portable device that uses a rapid spray of chemicals to put out small fires. Fire extinguishers are an essential part of fire prevention.
fire-resistant Made of materials which are designed to resist burning and withstand heat. Fire-resistant materials are essential to welding safety.
fixed classification system The way in which AWS classifies welding electrodes. The fixed classification system uses a limited amount of specific letters and numbers to describe an electrode's welding characteristics.
flammable A material that can quickly catch fire if it comes in contact with sparks or fire. Flammables must never be present in a weld area.
flat weld position A welding position used to weld from the upper side of the joint. Some FCAW electrodes are designated for only the flat or horizontal weld positions.
flowmeter A valve used to control the volume of gas flow. Flowmeters control the amount of gas flow into the line and usually include a gage displaying the gas volume in liters per minute (L/min).
flux A non-metallic material used to protect the weld puddle and solid metal from atmospheric contamination. In FCAW, flux material is contained in the core of the electrode.
flux-cored arc welding FCAW. A semi-automatic or automatic arc welding process. FCAW uses a continuously fed consumable electrode that contains flux in a hollowed-out center.
fluxing reactions A chemical process that cleans and purifies the weld metal. Fluxing reactions result when the flux material vaporizes and combines with the weld metal.
fume extractor Any device that uses suction to remove from the environment the smoke and gases generated during flux-cored arc welding. Fume extractors are sometimes called hoods.
fume extractor Any device that uses suction to remove the smoke and gases generated during flux-cored arc welding from the work environment. Fume extractors are sometimes called hoods.
fume plume A cloud-like area where welding fume collects. Fume plumes are hazardous to a welder's health and safety.
gas cylinder A metal container that stores shielding gases. Shielding gas cylinders are built specifically for each gas, and have different properties depending on the gas.
gas cylinders A metal container that stores shielding gases. Shielding gas cylinders are built specifically for each gas, and have different properties depending on the gas.
gas diffuser A device through which shielding gas flows. The gas diffuser is a component within gas-shielded welding guns.
gas hose A flexible tube used to deliver shielding gas. Gas hoses run from the gas cylinder's flowmeter and to the wire feeder.
gas marks A gas-shielded FCAW weld discontinuity that occurs when a gas bubble from the arc becomes trapped in the weld puddle and marks the weld bead after the slag solidifies. Gas marking is also called worm tracking.
gas metal arc welding GMAW. An arc welding process in which a bare, solid wire electrode and shielding gas are fed to the weld through a welding gun. GMAW is also sometimes referred to as MIG welding.
gas mixture A combination of gases used for shielding the weld. The most common gas mixture used in FCAW is an argon-carbon dioxide mixture.
gas nozzle A device that forces shielding gas to surround the electrode and arc. The gas nozzle is placed directly over the welding gun.
gas nozzle The device placed directly over the welding gun that forces shielding gas to surround the electrode and arc.
gas regulation equipment Equipment that controls the delivery of shielding gas to the welding area. Gas regulation equipment can include cylinders, flowmeters, gas hoses, and gas nozzles.
gas-shielded FCAW FCAW-G. A type of FCAW process that uses a flux-filled tubular wire electrode along with an external shielding gas. Gas-shielded FCAW is sometimes called dual shield welding.
gas-shielded flux-cored arc welding FCAW-G. A type of FCAW process that uses a flux-filled tubular wire electrode along with an external shielding gas. FCAW-G provides the weld area with double shielding protection.
generator A device that generates direct current through the use of a mechanical device like an engine or a motor. Generators are good alternative welding power sources because they run on diesel or gasoline fuel
goggles A type of tight-fitting eye protection that completely covers the eyes, the sockets, and the surrounding facial area. Goggles offer protection from impact, dust, chips, and splashes.
green steel Steel that is raw and untreated. Green steel rods and strips are used in the FCAW electrode fabrication process.
hand shield A metal piece on an FCAW-S gun that protects the welder's hands from the excessive amount of slag and spatter produced during FCAW-S. A hand shield is located above the trigger on an FCAW-S gun.
heat treatment A controlled heating and cooling process. Heat treatment changes the structure of a material and alters its physical and mechanical properties.
hood Any device that uses suction to remove the smoke and gases generated during flux-cored arc welding from the environment. Hoods are sometimes called fume extractors.
horizontal weld position A common welding position used for fillet and groove welds. Some FCAW electrodes are designated for only the flat or horizontal weld positions.
hydrogen H. A colorless, odorless gas, and the most abundant element on the planet. Hydrogen exposure can cause weld metal to crack.
hydrogen cracking A weld defect that occurs when hydrogen comes into contact with the weld metal. Low-hydrogen electrodes reduce hydrogen cracking.
improved toughness designator A letter and number used in the AWS classification system that specifies if the electrode meets requirements for improved toughness. The improved toughness designator is a supplemental designator.
input voltages The amount of voltage that a device needs to work properly. Input voltage is most frequently alternating current (AC).
insulated guide An insulated, threaded copper part that is attached to the end of the gun tube of a self-shielded welding gun. Insulated guides protect the end of the gun tube and are used as a gage for maintaining the proper electrical stickout specified for the self-shielded welding wire being used.
insulated nozzles A type of nozzle that uses a piece of non-conductive material to prevent it from becoming electrically charged. Insulated nozzles are used on gas-shielded FCAW guns to direct the shielding gas over the arc and ensure a quality weld.
inverter An energy-efficient welding machine that runs in CC and CV modes with variable frequencies, amplitudes, and AC/DC output. Inverter technology provides feedback on the welding parameters, so that the machine knows how much current is in the welding circuit at any one given time.
joining A process that brings materials together. Joining methods include fastening, adhesive bonding, and welding.
joint The meeting point of two materials that are fused together. Welding creates a permanent joint.
knurled A surface that has been marked with small diamond-shaped impressions. Knurled drive rolls are able to more easily grip FCAW electrodes without deforming them.
lead wire An electric wire that connects to a power source and is physically located in front of the direction of welding. Either DC or AC can power the lead wire.
low-alloy steels A steel that contains small amounts of intentionally added materials that change the properties of the metal. Common alloy elements include manganese, molybdenum, and nickel.
lubricant A substance used to prevent friction between two surfaces in relative motion. Lubricants reduce resistance, wear, and heat.
manual process A type of welding process in which the welder has control over all welding variables. An example of a manual welding process is SMAW.
manufactured Made or processed into a finished product. Manufactured parts are usually made by means of a large-scale industrial operation.
mechanical device A device that operates by reacting to and producing force and motion. Mechanical devices include engines and motors.
mechanical properties A property that determines a material's ability to compress, stretch, bend, scratch, dent, or break. The mechanical properties of a material describe the way a material responds to forces.
melt-off rate A measurement of the amount of filler metal deposited into a weld joint. The melt-off rate is measured in pounds per hour (lb./hr) or grams per minute (g/min).
metal transfer method The way in which filler metal is deposited into a weld. Examples of metal transfer methods include spray arc transfer and globular arc transfer.
molybdenum A hard, silvery-white metal. Molybdenum can add toughness, creep strength, and wear resistance to alloys.
multi-process machines Machines capable of welding with a variety of different welding processes. Multi-process machines include transformers.
negative charge An electric charge with a surplus of electrons. A negative charge is often symbolized by a minus (-) sign.
noxious Harmful or destructive to health. Noxious smoke can be produced during self-shielded flux-cored arc welding.
open classification system The way in which AWS classifies FCAW electrodes. In addition to the basic fixed classification system, additional designators further distinguish between electrode properties and the characteristics of their finished welds.
output The type of power that the welding power source produces. Forms of output include direct current (DC), alternating current (AC), constant current (CC), and constant voltage (CV).
penetration The depth to which the arc heat can melt the joint below the surface of the base metals. Penetration is directly affected by the amount of amperage.
percent fill The ratio of the weight of an electrode's core compared to the electrode's total weight. Percent fill can vary based on the materials included in an electrode's core and their density.
personal protection equipment PPE. Personal protection equipment consists of various safeguarding devices that workers use to prevent injury in the workplace. Common examples include safety glasses, gloves, masks, gowns, and earplugs.
physical properties The characteristics of a material that affect the way it performs a task. Physical properties describe the way a material responds to external environment conditions, such as temperature, chemical exposure, corrosion, and electricity.
polarity Having two oppositely charged poles, one positive and one negative. Polarity determines the direction in which current tends to flow.
porosity A welding discontinuity that results from trapped gases in a material and can weaken a weld. Porosity is characterized by the appearance of tiny voids or bubbles on a weld bead.
positive charge An electric charge with a shortage of electrons. A positive charge is often symbolized by a plus (+) sign.
power source A device that generates electricity. Arc welding power sources can be plugged into a wall outlet, or they can generate electricity through the use of a mechanical device like a motor or generator.
pressure vessels A container designed to hold liquids or gases at high pressures. Pressure vessels include gas canisters.
primary voltage shock An electrical shock from 120-480 volts that results from touching a lead inside a switched-on welding machine and then touching the welder case or other grounded metal at the same time. Primary voltage shock is an electrical risk in arc welding.
psi pound-force per square inch. A unit of pressure. Pounds per square inch is used in the English system of measurement.
ratio The relationship between two quantities. Ratios can be expressed as a fraction or as two numbers separated by a colon.
reconditioning The process of repairing or restoring something. Reconditioning welding electrodes can include baking them in a special oven at a specific temperature and for a designated length of time.
rectifier A device, such as a diode, that converts alternating current to direct current. Rectifiers allow meters to measure both DC and AC.
reverse polarity The arrangement of direct current arc welding cables and leads in which the electrode is the positive pole and the workpiece is the negative pole of the welding arc. Reverse polarity is often called direct current electrode positive or DCEP.
safety glasses Protective eyeglasses with metal or plastic frames and impact-resistant lenses that may or may not offer vision correction. Many safety glasses also have protective side shields.
scavenging elements A material that cleanses and purifies the weld puddle while it is still in a molten condition. Scavenging elements can help improve the quality of the finished weld.
secondary voltage shock An electrical shock from 60-100 volts that results from touching the electrode while another part of the body touches the workpiece. Secondary voltage shock is an electrical risk in arc welding.
self-regulating system A power source that automatically adjusts the electrode melt-off rate because of a change in arc length. Self-regulating systems include constant voltage power sources.
self-shielded FCAW FCAW-S. A type of FCAW process that uses a tubular wire electrode filled with fluxing agents that completely shield the weld area. FCAW-S does not require external shielding gas.
self-shielded flux-cored arc welding FCAW-S. A type of FCAW process that uses a tubular wire electrode filled with fluxing agents that completely shield the weld area. FCAW-S processes do not need external shielding gas.
semi-automatic process A type of welding process in which the power source maintains a uniform arc and a wire feeder controls the electrode. In semi-automatic welding, the welder is responsible for controlling the position of the welding gun as well as the direction and speed of travel.
setup All the necessary preparation of equipment that occurs before a weld can be executed. Setup time for self-shielded flux-cored arc welding is usually less than that for gas-shielded welding processes.
sheath A case or covering that usually encloses a tubular structure. In FCAW electrodes, a metal sheath surrounds a flux core.
shielded metal arc welding SMAW. A manual arc welding process that uses a flux-coated consumable rod electrode. SMAW is also sometimes referred to as stick welding.
shielding Protection which keeps the weld puddle and arc from reacting negatively with the atmosphere. Shielding can be provided by either a gas or a type of flux.
shielding gas An inert or slightly active gas that protects the weld puddle and arc from reacting negatively with the atmosphere. Shielding gases are used in some arc welding processes.
slag Cooled flux that forms on top of the weld bead. Slag protects cooling metal and is then chipped off.
slag inclusions A welding discontinuity resulting from the combined dissolution of flux and nonmetallic impurities. Slag inclusion can affect the strength and integrity of a weld in its final application.
slip-on nozzles A type of nozzle in which the insulator can come apart from the nozzle. Slip-on nozzles are used on gas-shielded FCAW guns.
spatter Liquid metal droplets expelled from the welding process. Spatter can leave undesirable dots of metal on a workpiece surface.
spool A cylindrical device used for storing, winding, and unwinding welding electrodes. Spools are used in semi-automatic and automatic welding processes.
spray arc transfer A type of metal transfer in which the metal at the end of the wire melts into small, fine droplets. Spray arc transfer creates a stable arc and little spatter.
stainless steels A group of steels that contains a minimum of 10.5% chromium. Stainless steel is very hard and exhibits excellent corrosion resistance.
stick electrode A consumable electrode used in SMAW that conducts electricity to the arc but also melts into the weld as a filler metal. Stick electrodes have metal cores that are coated in flux materials.
straight polarity The arrangement of direct current arc welding cables and leads in which the electrode is the negative pole and the workpiece is the positive pole of the welding arc. Straight polarity is often called direct current electrode negative or DCEN.
strength The ability of a metal to resist forces that would otherwise break or deform the metal. A metal exhibits tensile, compression, or shear strength, depending on the direction of the force.
tensile strength A material's ability to resist forces that attempt to pull apart or stretch it. Tensile strength is usually expressed in pounds per square inch (psi) or in kilopascals (kPa).
terminals A connecting point in a circuit where a wire is attached to create an electrical connection. Terminals can be either positive or negative.
toughness The ability of a metal to absorb energy without breaking or fracturing. Toughness is a key property because it determines the ability of a material to withstand a sudden stress.
transformer A device that transfers electrical energy from one circuit to another, without changing the frequency, using electromagnetic induction. A transformer is most often used to change the voltage of an input.
usability An electrode's polarity characteristics and general operating characteristics. Usability is often indicated in an AWS classification by either a "G," a "GS," or any number ranging from 1 to 14.
valve cap A device used to protect the gas valves on a gas cylinder. Valve caps are an important safety device included on gas cylinders.
vaporizes The process by which a solid or liquid becomes a gas. Vaporization of the materials at an FCAW electrode's core creates fluxing reactions within the weld metal.
ventilation A means of providing fresh air. For the safety of the welder, welding requires proper ventilation.
voltage The electrical force or pressure that causes current to flow in a circuit. Voltage is measured in volts.
water-cooled gun A type of welding gun that uses water to cool the welding gun. Water-cooled guns often operate at a higher duty cycle than air-cooled guns.
weld bead The end product of a welded joint. Weld beads result from a welding pass that deposited filler metal.
weld pass The progression of welding across a joint, which results in a weld bead. A weld pass can be either single or multiple.
weld puddle The small area of molten metal that forms during welding, and which, when cooled, forms the permanent joint. Weld puddles are also sometimes called craters or weld pools.
welder The person who performs a weld. Some materials may describe the power source that provides the electricity needed to perform an arc weld as a welder.
welding A joining process that permanently bonds two separate components together. Welding uses heat, pressure, or a combination of elements to make one new part.
welding gun An instrument used in semi-automatic welding processes. Welding guns conduct electricity, guide the electrode, and in some cases, release shielding gas.
welding helmet A protective eye and face device worn during welding to protect the welder from the arc's harmful rays and intense bright light. A welding helmet is also called a welding shield.
welding positions The position in which the welder performs a weld. The different welding positions include overhead, vertical, flat, and horizontal-position welding.
welding shield A protective eye and face device worn during welding to protect the welder from the arc's harmful rays and intense bright light. A welding shield is also called a welding helmet.
wire feeder The device that feeds wire to the welding gun. Wire feeders are either built inside or set beside the power source.
wire feeder welder A small, self-contained welding unit housing both the power supply and the constant speed wire feeder. Wire feeder welders are economical and good for performing light-duty FCAW.
work clamp The component that is connected to the welding power source by the work cable and provides ground for the FCAW circuit. Work clamps are sometimes called ground clamps.
workpiece A part that is being worked on during manufacturing. The workpiece may be subject to cutting, welding, forming, or other operations.
worm tracking A gas-shielded FCAW weld discontinuity that occurs when a gas bubble from the arc becomes trapped in the weld puddle and marks the weld bead after the slag solidifies. Worm tracking is also called gas marking.