What welding terms should welders know?

A well-developed welding vocabulary is crucial to rounding out your welding skills and abilities. Certain procedures require comprehension of these terms and phrases. Knowledge of welding terms prioritizes you over your competition when looking for welding jobs. You should practice learning welding vocabulary as often as you work with your welding machine.

Welding isn’t just about melting metals together. There’s a whole other component to it that many people overlook: terminology.

Though some might consider it to be confusing jargon, welding terms actually convey critical information necessary for whatever welding project is before you. That’s why knowing common welding terms and phrases builds a solid foundation upon which your welding skills can flourish. The more you know about how to talk about welding, the better your physical skills will become.

To aid you in laying that foundational knowledge, we’ve put together a list of the most common welding terms you’ll encounter. We don’t claim to be the experts on what proper welding is and isn’t; this isn’t a technical document by any means. With that said, each of these terms can be found on a variety of welding websites as necessary knowledge. We encourage you to dig deeper into terms you aren’t familiar with and continue your learning beyond this post.

Now, here are the most common welding terms you should know—and their definitions, of course.

The Most Common Welding Terms You’ll Encounter

Below, you’ll find an alphabetized list of welding terms. Each section is broken up into groupings of letters, so you can more easily find the term you’re looking for.

A

• AISI: American Iron and Steel Institute
• ASME: American Society of Mechanical Engineers
• ASTM: American Society for Testing and Materials
• Acetylene: “a highly combustible gas that is made of carbon and hydrogen that is used in gas welding”
• Alloy: term used to describe a mixture of elements, one of which is metal
• Alternating current (AC): type of current characterized by a sin wave; current “reverses back and forth from positive to negative”
• Arc blow: describes the deflection of the electric welding arc because of magnetic forces found in the base metal
• Amperage: otherwise known as current; measures the flow of electricity “through a given point in a conductor per second”
• Anneal: “process of heating a metal to a temperature below the critical range, followed by a relatively slow cooling cycle to induce softness and remove stresses’
• Autogenous weld: a “fusion weld made without the addition of filler metal”
• Automatic welding: type of welding done by a machine; robot “controls joint alignment by using an automatic sensing device”

B 

• Backhand welding: technique wherein “the welding torch or gun is directed opposite the progress of welding”
• Backup strip: “a strip or section of steel butted up to an open gap between two pieces of steel”; used when welding with 7018 “to provide a surface for the electrode to weld to”
• Bead weld: type of weld that resembles one or more string of beads
• Blanking: a process in which materials are cut “to size for more manageable processing”
• Bonded fluxes: created by “binding an assortment of powder together and then baking at a low temperature”; advantage lies in the fact that you can add more alloying ingredients if necessary
• Boxing: “continuation of a fillet weld around a corner of a member as an extension of the principal weld”
• Brazing: “a welding method using a filler metal that is liquefied at a temperature above 800 F is distributed within a groove, flange or other type of joint and distributed through the joint via capillary action.”
• Butt joint: joint made by welding two metals together on the same plane
• Buzz box: term used to describe a general-purpose arc welder; “derived from the sound made when the welder is running”

C

• Cap: “final bead on a groove weld”
• Casehardening: heat-treatment process “applied to steel or iron-carbon alloys, by which a harder outside is obtained over a softer interior; depth or increased hardness depends upon length of treatment”
• Cold lap: “incomplete fusion or overlap”
• Collimate: to “render parallels to a certain line or direction”
• Consumables: materials that are eroded during use, such as “electrodes, nozzles, shields, caps and swirl rings”

D

• Deoxidizers: elements used in welding electrodes and wires “to prevent oxygen from forming harmful oxides and porosity in weld metal”
• Depth of fusion: how far the filler metal penetrates into the surface of the welded metal
• Die welding: used in forge welding; “fusion is produced by heating in a furnace and by applying pressure by means of dies”
• Dig: technique that’s also known as arc control; used to avoid sticking the electrode in the weld when a short arc length is used; the power source is given “variable additional amperage during low voltage (short arc length) conditions while welding”
• Dip brazing: “brazing process in which bonding is produced by heating in a molten chemical or metal bath and by using a nonferrous filler metal having a melting point above 800 ºF (427 ºC), but below that of the base metals. The filler metal is distributed in the joint by capillary attraction. When a metal bath is used, the bath provides the filler metal”
• Direct current (DC): current flows one way, from negative to positive; while current always flows in the same direction, you can change the polarity via welding leads
• Direct current (DC) electrode negative: electricity flows out of the welding rod/wire and disperses into the work piece
• Direct current (DC) electrode positive: electricity flows into the welding rod/wire, “therefore putting more heat at the rod or wire end”
• Double arcing: process by which “the welding or cutting arc of a plasma arc torch does not pass through the constricting orifice but transfers to the inside surface of the nozzle. A secondary arc is simultaneously established between the outside surface of the nozzle and the workpiece”
• Drag angle: “travel angle when the electrode is pointing backward”; can be used “to define the position of welding guns, welding torches, high energy beams, welding rods, thermal cutting and thermal spraying guns”
• Ductility: a material’s ability “to become permanently deformed without failure”
• Duty cycle: “percentage of time a machine can run in a ten minute period of time before it overheats”; usually expressed in a percentage

E

• Edge joint: type of joint where the edges of 2+ parallel members are joined
• Electrode: filler metal that is often called a “rod” in stick welding or “wire” in MIG and flux-core welding; can be covered with flux or simply bare metal
• Electrode skid: describes the “sliding of an electrode along the surface of the work during spot, seam, or projection welding”

F

• Faying surface: surface of a member that is in contact with another member to which it is joined; in other words, the point where two pieces meet and touch
• Flash burn: burn similar to that of a sunburn that results from the UV rays of the welding arc; both skin and eyes can be affected; this is the main reason why you wear protective clothing and eye protection when you weld
• Flux: cleaning solution meant to dissolve rust, release trapped gases, and prepare metals “to be welded, soldered or brazed”
• Forehand welding: technique in which “the welding torch or gun is directed toward the progress of welding”
• Free bend test: destructive test in which a weld is ground down and the test coupon is bent in a jig and visually inspected
• Friction welding: type of welding “which produces coalescence of material by the heat obtained from a mechanically induced sliding motion between rubbing surfaces”

G

• Galling: the “condition between rubbing surfaces where high spots or protrusions on a surface become friction welded to the mating surface, resulting in spalling and further deterioration”
• Galvanized: “An electrochemical process where mild steel is hot-dipped into liquid zinc to make it anti-corrosive”

H

• Heat affected zone: the “portion of the base metal whose structure or properties have been changed by the heat of welding or cutting”
• Hold time: duration of time that pressure is maintained at the electrodes after the welding current has stopped; oftentimes hold time is used to continue the flow of shielding gas as the weld cools, in order to maintain a clean environment
• Hot short: process where “metal is heated to that point, prior to melting, where all strength is lost but the shape is still maintained”

I

• Inclusion: foreign material such as “slag, flux, tungsten, or oxide” that’s trapped within the weld

J

• Jig: “used to hold metal into place when fabricating”; they can be simple or complex, depending upon what process they are used for; great way to speed up the fabrication process in a number of ways

K

• Kerf: the “width of a piece of metal removed by cutting”
• Killed steel: describes steel that’s “been sufficiently deoxidized during the melting cycle to prevent gases from evolving during the solidification period”

L

• Lap joint: describes a type of joint wherein 2 metals are overlapped via a fillet, plug, or slot weld

M

• Macro testing: a destructive test, wherein “sections of a weld are polished, etched and examined under a microscope for defects”
• Mandrel: “metal bar serving as a core around which other metals are cast, forged, or extruded, forming a true, center hole” 

N 

• NDE: stands for nondestructive examination; used to determine “the suitability of some material or component for its intended purpose using techniques that do not affect” the serviceability
• Non-ferrous: describes any metal not made from iron ore

P

• Parent metal: “primary piece of metal that you are welding on”
• Pass: describes the motion of welding along one axis of the weld, from beginning to end
• Peening: process of using a hammer or other large object of force and applying it full-strength to the metal workpiece
• Percussive welding: a type of welding in which high temperatures are applied “to the welding site, just before pressure is applied”
• Pitch: the measurement of weld spacing, taken from center-to-center between the welds
• Porosity: gas pockets trapped in the weld; results from lack of shielding gas in MIG and moisture in flux welding
• Pulsing: technique of welding that prioritizes controlling the amount of current, polarity, and duration of the weld in a particular sequence

Q

• Quench: process in which metals are cooled rapidly; techniques include air, oil, and water quenching, as well as many others

R

• Rated load: “amperage and voltage of the power source is designed for producing a given specific duty cycle period”

S

• SAE: stands for the Society of Automotive Engineers
• Shear: “force which causes deformation or fracture of a member by sliding one section against another in a plane or planes which are substantially parallel to the direction of the force”
• Shielding gas: gas or gases used during welding to create a clean environment for the weld to ensure a strong bond
• Single-phase circuit: electrical circuit that generates only 1 “alternating cycle within a 360-degree time period”
• Slag: “solidified flux which is left on the weld”; removed via a wire brush, hammer, or angle grinder
• Slugging: “adding a separate piece or pieces of material in a joint before or during welding that results in a welded joint not complying with design, drawing, or specification requirements”
• Soapstone: a soft stone made of compressed talc; used to temporarily mark on steel
• Spacer strip: a “metal strip or bar prepared for a groove weld, and inserted in the root of a joint to serve as a backing”
• Spalling: describes the “loss of particles or pieces from a surface due to cracking”
• Spool gun: used in MIG welding; pistol grip attached to a wire spool that allows you to control the feed of wire; often used in welding aluminum
• Stick-out: how much “the wire sticks out from the end” of a MIG welding nozzle
• Stinger: the “electrode holder” as it’s called in the shop or field
• Stitch welding: “use of intermittent welds to join two or more parts”

T

• Tack weld: single beads of weld used to hold work pieces in place before full welding begins; used mostly to position work, rather than for any strength
• Tempering: term used to describe the “process of reheating hardened steel below the lowest critical temperature and then allowing it to cool to make the steel stronger”
• Touch start: starting procedure used in TIG welding that requires low voltage and low amperage; tungsten touches the work piece first and then as it is lifted away, the arc is established

U

• Undercut: “Channels melted into the base metal adjacent to the toe or root of a weld and left unfilled by weld metal”
• Underfill: a “depression on the face of the weld or root surface extending below the surface of the adjacent base metal”

W

• Weld gauge: device used “for checking the shape and size of welds”

Memorizing welding terms can oftentimes feel like learning a new language. But can French help you build your own roll cage or show you the strongest weld joints?

Learn More About Welding

Even though welding is a physical skill that requires manipulation of objects, there’s a lot you can learn about it online. In fact, a number of welders have taken to YouTube to share their knowledge. Search through what’s posted and you’re sure to find a video or two that sparks your interest and teaches you something new.

Beyond watching videos, though, you can also join local welding communities. These groups may or may not be official, but it’s definitely easier to learn about welding by spending time with those who have a passion for it.

Finally, you can always find resources on welding here. We strive to bring you informational and inspirational content that allows you to imagine and create whatever you can dream up. Whether it’s prospective welding careers, the future of the art, or even teaching yourself new methods, there’s always something to be said about welding.

Are there any welding terms we missed? What other resources do you find helpful for learning about welding? Share your comments with us below.