Welder’s Terminology: A Glossary for Beginners

A

Alloy: – A metal made from two or more combined elements.

Annealing: – Annealing is the slow cooling of the metal to reduce internal stresses, make the material softer and change ductility, among other things.

Arc Blow: – A phenomenon where the welding arc is deflected from its normal path due to magnetic forces.

Arc Length: – The distance between the tip of the electrode and the workpiece during welding.

Arc Time: – The total time the welding arc is active during a welding operation.

Arc Welding: – A type of welding that uses an electric arc to create the heat to melt the metals being joined.

B

Backpurge: – Introducing a shielding gas to the backside of a weld joint to prevent oxidation.

Base Metal: – This has two meanings: 1) the metal that will be cut or welded; 2) in an alloy, it is the largest proportion of the metal.

Base Metal: – The metal being welded or the main component of a welded joint.

Bead Appearance: – The visual characteristics of a weld bead, indicating the quality and penetration of the weld.

Bevel: – An angled cut edge on a piece of metal that is being prepared for welding.

Bond: – The point where the welding metal is joined with the base metal.

Brazing: – A joining process where metals are bonded using a filler metal with a melting point above 450°C (842°F).The filler metal is nonferrous and has a melting point below the melting point of the base metal.

C

Capping Pass: – The final weld pass that provides the desired shape and appearance to the weld.

Carbon-Arc Welding:  – A welding method that involves creating an arc between a carbon electrode and a metal.

Case Hardening: – This process hardens the surface of the metal by using inward diffusion with gasses or a liquid before applying heat.

Coated Electrode: – The electrode is covered with flux through dipping or painting. When heat is applied, the flux produces a gas that shields the arc.

Consumable Electrode: – A type of electrode that becomes part of the weld during the welding process, such as in stick welding.

Covered Electrode: – The metal electrode is covered with asbestos, flux, paper or other materials to make the arc more stable and improve the welding metal.

Critical Temperature: – The temperature at which the material transitions from one crystalline form to another.

Current Density: – The amount of amperes applied per square inch across a particular area.

Cutting Torch: – This welding tool controls gas for preheating the metal, as well as the oxygen for cutting the metal.

D

Dilution: – The mixing of the base metal with the filler metal during welding.

Direct Current Electrode Negative (DCEN): – The metal being welded is the positive pole, and the electrode is the negative pole of the arc.

Direct Current Electrode Positive (DCEP): – DCEP is the opposite of DCEN. The welded metal is the negative pole, and the electrode is the positive pole of the arc.

Distortion: – The unwanted change in shape or dimensions of a welded part due to heat.

Dual Shield Welding: – A welding process that combines flux-cored arc welding with a shielding gas.

E

Electric Arc: – An electrical current that forms in the gap between two electrodes creates an electric arc.

Electrode: – There are many types of electrodes used in welding. An electrode conducts the electrical current through a work piece to create the weld. Some electrodes are consumed in the welding process while others are not.

F

Filler Metal: – Metal added during welding to fill the joint and create a stronger bond.

Fillet Weld: – A weld joint where two surfaces are joined at right angles in the form of a triangle.

Flame (Oxygen) Cutting: – The chemical action of oxygen applied to the elements in the base metal at high temperatures cuts ferrous metals.

Flame (Oxygen) Gouging: – This method is used to create a groove in the metal using an oxygen-cutting tool.

Flame Hardening: – The metal surface is hardened using a heated flame, followed by a quick quench.

Flame Softening: – This technique makes metal softer by first heating it and then slowly letting it cool down.

Flash Welding: – A welding process that uses the heat generated by electric resistance between two overlapping workpieces.

Flashback Arrestor: – Safety devices used to prevent the backflow of gases into gas hoses in oxy-fuel systems.

Flux: – This material cleans metals to prepare them for welding. The substance prevents oxidation of the molten metal.

Forehand Welding: – The flare is aimed at the metal ahead of the completed weld.

Friction Stir Welding (FSW): – A solid-state welding process that uses frictional heat to join materials.

G

Gas Carbon-Arc Welding: – The weld is accomplished by an electrical arc between a carbon electrode and the welding metal.

Gas Metal Arc Welding (GMAW/MIG): – A welding process that uses a continuous wire electrode and a shielding gas.

Gas Tungsten-Arc Welding, GTAW: – Also called Tungsten-Inert-Gas (TIG) welding, this arc welding method uses an electrode made from tungsten with inert gas.

Gas Welding: – Welding type where the heat for welding comes from a gas flame.

Groove Weld: – Creating this weld requires filler material that goes in the groove between two metals to join them.

H

Hammer Welding: – Hammering two pieces of heated metal together.

Hardfacing: – Depositing wear-resistant material on a surface to improve its durability.

Hardsurfacing: – The application of a hard metal layer to a softer base metal for wear resistance.

Heat Input: – The amount of energy applied to the weld during the welding process.

Heat-Affected Zone (HAZ): – The area around the weld where the base metal has experienced changes in its properties due to heat.

Hot Pass: – An intermediate pass made after the root pass to refine the weld profile.

Hydrogen Brazing: – A type of brazing in a furnace under a hydrogen atmosphere.

Hydromatic Welding: – This method is also called pressure-controlled welding. Spot welds are made in a sequence using
more than one electrode under pressure.

I

Inert Gas: – Gas that doesn’t combine chemically with metal. It is non-reactive gas, such as argon or helium, used in welding to shield the weld area from atmospheric contamination.

Interpass Temperature: – The temperature range between the completion of one pass and the start of the next pass in multi-pass welding.

Ionization Potential: – The amount of electrical voltage needed to create ionization of the materials, which either adds or removes electrons.

J

J-groove Weld: – A groove weld joint with the joint configuration shaped like the letter “J.”

Joint: – The area where materials are fused together.

Joint Design: – The specific way that two pieces of metal are arranged to be welded together. There are many different types of joint designs, each with its own advantages and disadvantages.

Joint Preparation: – The process of preparing the joint surfaces for welding, including cleaning and beveling.

K

Kerfs: – The width of a piece of metal removed by cutting.

Keyhole Welding: – A welding technique where the arc creates a keyhole in the molten metal.

L

Liquidus: – The lowest temperature at which the metal or alloy turns liquid.

M

Metal-Arc Welding: – This arc welding method uses metal electrodes.

MIG Welding: – See gas metal arc welding (GMAW).

Multi-Impulse Welding: – Making more than one weld by using multiple pulses of electricity.

N

Non-Destructive Testing (NDT): – Testing methods, like X-rays or ultrasonic testing, used to evaluate the properties of a weld without destroying it.

Non-Ferrous: – These metals do not have any iron, such as titanium, nickel, lead, copper, bronze, brass and aluminum.

Normalizing: – In this process, iron-based alloys are heated to 100°F above the critical temperature and then allowed to cool down in air temperature.

O

Oxyacetylene Welding: – The temperature needed for welding comes from burning a combination of acetylene and oxygen.

Oxy-Fuel Cutting: – A cutting process that uses oxygen and a fuel gas to melt and remove metal.

Oxy-Hydrogen Welding: – The heat source for this welding method is a mixture of oxygen and hydrogen.

Oxy-Natural Gas Welding: – In this welding process, the heat necessary to make the weld comes from burning natural gas with oxygen.

Oxy-Propane Welding: – The heat for welding comes from burning a mixture of oxygen and propane.

P

Peening: – Small hammer blows stretch the surface of cold metals and reduce stress in the metal.

Percussive Welding: – This method involves applying high temperature to the welding site, just before pressure is applied.

Plasma Arc Cutting: – A cutting process that uses a high-velocity jet of ionized gas to melt and remove metal.

Plug Weld: – A hole is cut in one piece of metal. Another piece of metal is put behind the hole, and the weld is made in the hole to connect the two pieces of metal.

Polarity: – The direction of electrical flow in welding circuits, either direct current (DC) or alternating current (AC).

Porosity: – This means that gas pocket or inclusions are present in the welded material. They are small cavities or holes in the weld caused by trapped gas during solidification.

Post-Weld Heat Treatment (PWHT): – Controlled heating and cooling of a welded part to relieve residual stresses.

Preheating: – Raising the temperature of the base metal before welding to reduce the risk of cracking.

Pressure Controlled Welding: – This welding technique creates spot or projection welds in sequence with pressure applied to the weld made by multiple electrodes.

Pressure Welding: – Pressure fuses the materials.

Projection Welding: – A resistance welding technique used between two surfaces or the ends of one member and the surface of another.

Pulsation Welding: – The welds for each spot receive more than one electrical pulse without the electrode moving or releasing the pressure.

Pulsed Welding: – A welding technique where the power source alternates between high and low energy pulses.

Purge Gas: – Gas used to remove oxygen and contaminants from the backside of a weld.

Q

Quenching: – The rapid cooling of metal using water, air or oil.

R

Resistance Welding: – Heat is generated through the resistance to the electric current flowing through the circuit of which the welded metal is a part.

Root of Joint: – This is the part where the materials are joined are the smallest distance from each other, which could be an area, a line or a point.

Root of Weld: – The point where—when observed from a cross-section viewpoint—the bottom of the weld fuses with the base metal.

Root Opening: – The separation between the edges of the joint at its root.

Root Pass: – The first weld pass in a multi-pass joint, usually made from the root side.

Run-off Tab: – A piece of metal added at the end of a weld to ensure complete fusion.

S

Seal Weld: – The main purpose of this weld is to get a tight connection and prevent leaks.

Seam Weld: – A type of weld used in joining rolled or formed sections, usually along a longitudinal seam. This weld forms a long line that connects joints in the welded material.

Shielding Gas: – Gas used to protect the weld pool from atmospheric contamination during welding.  Common shielding gases include argon, helium, or mixtures of the two.

Slag: – The by-product of the welding process that forms a glassy layer on the weld. Slag must be chipped away to reveal the finished weld. It is the residue left on the surface of the weld after flux-covered electrodes burn.

Spatter: – Small particles of molten metal expelled during welding that do not form part of the weld.

Stick Welding: – Also known as Shielded Metal Arc Welding (SMAW), a type of arc welding that uses a consumable electrode with a flux coating.

T

Tack Weld: – A small, temporary weld used to hold parts in place before the final welding.

TIG Welding: – Also known as Gas Tungsten Arc Welding (see GTAW).

Ultrasonic Testing (UT): – A non-destructive testing method using high-frequency sound waves to inspect welds.

U

Undercut: – A groove or depression along the weld toe or in the base metal adjacent to the weld.

W

Weaving: – A technique of moving the welding arc from side to side to create a wider weld bead.

Weld Bead: – The deposited material in a single pass of a welding operation.

Weld Cracking: – The formation of cracks in the weld metal or heat-affected zone.

Weld Crater: – The depression left at the end of a weld bead due to the reduction in heat input.

Weld Decay: – The loss of corrosion resistance in stainless steel due to sensitization during welding.

Weld Joint Efficiency: – The ratio of the strength of a welded joint to the strength of the base metal.

Weld Joint: – The area where two or more pieces of metal are joined together.

Weld Metal Composition: – The elemental composition of the metal deposited during welding.

Weld Metal: – The metal that has been melted and fused during welding.

Weld Overlay: – Applying a layer of weld metal to the surface of a component for protection or enhancement.

Weld Pass Sequence: – The order in which successive weld passes are made on a joint.

Weld Pass Thickness: – The thickness of the weld metal deposited in a single pass.

Weld Pass: – A single progression of the welding process along the joint.

Weld Passivation: – Treating the weld to enhance corrosion resistance by forming a protective oxide layer.

Weld Pool Dynamics: – The behavior and movement of the molten metal during the welding process.

Weld Pool: – The molten metal during welding that solidifies to form the weld.

Weld Reinforcement: – The additional height of the weld bead above the surface of the base metal.

Weld Seam: – The line where two materials are joined by welding.

Weld Strength: – The ability of a weld to withstand applied forces without failing.

Weld Toe: – The junction of the weld metal and the base metal at the outermost point of the weld.

Weld:  – The joint created by welding two pieces of metal together.

Weldability: – The ease with which a material can be welded under specific conditions.

Welding Certification: – Formal recognition that a welder has demonstrated proficiency in specific welding processes and techniques.

Welding Electrode Holder: – A device used to hold and control the electrode during manual arc welding.

Welding Engineer: – A professional with expertise in the science and technology of welding.

Welding Flux: – A substance that promotes coalescence during welding by preventing oxidation.

Welding Fume Extraction: – Systems or devices used to remove welding fumes and gases from the work environment.

Welding Gas Regulator: – A device used to control and regulate the flow of shielding gas in welding.

Welding Gun: – The handheld device used in processes like MIG welding to feed the electrode and shielding gas.

Welding Helmet: – Protective headgear worn by welders to shield their face and eyes from arc radiation.

Welding Hood: – Another term for a welding helmet, providing protection for the welder’s face and eyes.

Welding Inspector Certification: – A qualification indicating that an individual has met specific standards for inspecting welds.

Welding Inspector: – A professional responsible for ensuring that welding procedures and work meet specified standards.

Welding Position: – The orientation of the weld joint concerning the earth’s gravitational pull, such as flat, horizontal, vertical, or overhead.

Welding Positioner: – A device used to rotate or manipulate the workpiece for welding in the most suitable position.

Welding Power Source: – The machine providing the electrical power for welding.

Welding Procedure Specification (WPS): – A document outlining the welding parameters and procedures for a specific welding task.

Welding Procedure: – A detailed plan specifying the welding parameters and techniques to be used for a specific application.

Welding Rod: – A term often used for the electrode in arc welding processes.

Welding Safety Gear: – Protective equipment worn by welders, including gloves, aprons, and safety glasses, to ensure safety during welding.

Welding Symbols: – Pictorial representations on drawings indicating the type and location of welds.

Welding Technique: – The method and skill employed by a welder to create a quality weld, considering factors like movement, angle, and heat control.

Welding Torch: -The handheld device used in oxy-fuel welding and cutting.

Welding Travel Speed: – The rate at which the welding arc progresses along the joint.

Welding Wire Feed Speed: – The rate at which the welding wire is fed into the welding arc.

Welding Wire: – The consumable wire used in processes like MIG and flux-cored arc welding.