Basic Welding Terms

The following are my non-technical definitions for some basic welding terms. These are good for the home hobbyist and those just coming into the welding field. Most people don't want to sit down and learn all the welding vocabulary and I don't blame 'em, I didn't either. But if you will learn these, you'll be a cut above most beginners.

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Arc Blow — is the arc going everywhere that you DON'T want it to go. It only happens in DC, happens a lot welding up into a corner, and is believed to be caused somehow by magnetisim. It sometimes helps to move the work clamp to a different position on the steel.

Arc Cutting — can be done with a 6010 or 6011 rod with the machine turned up to "warp 10". (very hot) Other rods can be used but these two are the best. It is where you cut through the steel using the force of the arc. It doesn't make the prettiest cut, but will do in a pinch when you don't have a torch.

Arc Gouging — is where the steel or metal is cut using an arc from a carbon electrode. The electrode is solid carbon wrapped in copper for conductivity. The stinger has compressed air and when a button is pushed, it blasts air at the molten metal being cut. The machine is turned to "warp 10" which means you are using a LOT of amps (heat).

An example of this is when we went to a job where 5 stainless steel tanks about 10 stories high had almost every weld flunk an x-ray test. We gouged the weld on the outside, then re-welded them. We then gouged the welds on the inside and re-welded into our previous weld.

Thick stainless can't be torch cut, and even if it could, the heat would cause it to warp. Arc gouging keeps the heat concentrated at the cut.

Alloy — is an element added to a metal. An example is mild steel with chromium (resist rust), and nickel (makes it less susceptible to oxidation which is rust) which makes a form of stainless steel.(the most common stainless is 304)

Alternating Current — reverses back and forth from positive to negative on a sine wave. It makes for an erratic arc on most welding processes and that is why DC is preferred.

Amperage — measures electricity flowing and is the same as current, which is your heat.

Arc — is what is between the end of the electrode and the base metal. The resistance causes heat.

Automatic Welding — is a weld made by equipment such as robots.

Backup Strip — is a strip or section of steel butted up to an open gap between two pieces of steel. 6010 welding rods can be used for open butt welding, but 7018 cannot and requires a backing strip to provide a surface for the electrode to weld to. Some backup strips are cut off and some are left in place.

Bead - the deposited filler metal on and in the work surface when the wire or electrode is melted and fused into the steel. A stringer bead is a narrow bead with only a dragging motion or light oscillation, while a weave bead is wider with more oscillation.

Bevel - an angle cut or grinded at the edge of the work-piece to allow more penetration for a stronger weld.

Blown-up - what you will be if you weld or cut on containers with fumes. NEVER weld or cut on any container unless it is new or you know it has been cleaned and safety certified! Containers can be toxic, flammable, or explosive.

Brush - steel wire bristled hand brush, disc brush for a hand grinder, cup brush for hand grinder, or wheel brush for bench grinder. They're used to clean mill scale, oxidation, dirt, oil etc. off of steel surfaces. Cleanliness is of utmost importance on the work piece to assure there will be no weld defects. It is important to use a stainless steel brush and mild steel brush correctly.

Build-Up Weld - building up the surface of a steel part such as the teeth of a sprocket, surface of an idler wheel (keeps the track in place on tracked vehicles such as bull dozers or cranes), or bucket on a front-end loader. In most cases it is far less expensive to have a welder build up a component than it would be to replace the part. Build-up welds are usually done with hard surface electrodes.
It is also a good way for a new welding student to learn proper re-starts and tie-ins.

Busted Out - failing a weld test because of defects in the welds. "He busted out on his test plates and didn't get hired."

Butt Joint - just what it sez'…two pieces butted up against each other. Only the top and bottom surface can be welded. Without good penetration, this weld does not have the strength of a multi-pass fillet weld, or beveled joint.

Cap - the last bead of a groove weld, it can be made with a weave motion back and forth, or with stringer beads tied into each other.

Also what you need to wear on your head when welding Mig vertical, or any process overhead, to keep hot sparks off of your head. (see Cussing.) Welder's hats have a small bill and are so high they need a warning light to keep airplanes from crashing into them. This is so they can be turned and pulled down over your ear when welding pipe and your head is tilted. You don't EVEN want a glob of molten metal going into your ear! You can literally hear it sizzle as you suffer through the burn. Welding hats could win any ugly hat contest with all the crazy polka dots, paisley and other crazy designs.

Cardinal Sin of Welding - see undercut.

Coalescence - ah, this is when the metal or steel is fused (joined) grasshopper.

Coated Electrode - That is the flux on the filler metal of a welding rod. They used to use bare rods only in the horizontal position. Someone noticed that a rusty rod worked better than a brand new one so they started experimenting with different coatings on different rods. They found that some coatings produced a shielding gas that protected the weld pool from contaminants in the atmosphere. Contaminants cause Porosity and Longitudinal Cracking. With the weld pool protected the weld was smooth and sound and could be used in different positions rather than just flat. I can only imagine how many times those bare rods would get stuck!

Concavity - It is when a Fillet Weld bead sags inward from the root Face to the Root.
Consumable Insert - This is where a filler wire or rod is in a gap and you weld it into the base metal along with your wire or rod. It becomes one with the weld grasshopper.
Convexity - This is when a Fillet Weld bead protrudes outwards from the Root to the Face.

Corner Joint - One of the five basic weld Joints. It is when the edges of two plates butt up to each other at a 90 degree angle. It usually provides a groove to fill providing good Penetration.

Cover Glass or Cover Plate - Clear glass or plastic lens in a hood or cutting goggles that protects the #5 (for cutting) or #10,11, 12 lens (for welding) from getting spatter on them. Gripes the heck oughta' me when a student forgets to put it in when they change out the lens. They then weld with it and the spatter ruins the # glass which ain't cheap! You should change the cover plates often as they restrict your view when they get spattered or scratched up.

Crack - Where the weld fractures or breaks apart. A good example would be welding on cast iron. If it is not pre-heated and post-heated right, or if the wrong electrode is used, it will crack BIG TIME. Sometimes the crack will run right in front of the weld pools as you weld.

You should pre-heat, post-heat, and run cast iron rod, which has a nickel content. A trick to keep a crack from spreading is to drill a hole before and after the crack you are about to weld. Run the weld, and then fill the holes. The holes keep the crack from spreading.

Crater - At the end of the weld bead you burn into the steel without depositing any filler metal which leaves a depression in the base metal. When doing a Restart, you want to start at the end of the crack, weld back into where the weld stopped, and then proceed in the direction you were welding. This pre-heats and gives a good Tie-in into the bead you just laid.

Critical Temperature - This is when the base metal transitions from solidus to liquidus as you heat it during the welding process. It's right at that point where it goes from being solid mass, to melting and becoming liquid. This is a great term to discuss at a cocktail party to make you sound smart, ESPECIALLY if your audience doesn't know much about welding!

Current - In the electric circuit the current is the flow of electricity. What you're welding on resists the flow and that forms heat. AMPS are the measurement of your current. To get a bit more technical, current is negatively charged electrons passing through a conductor, which is usually a wire.

Cylinder - What we store oxygen and acetylene in for cutting, and SHIELDING GAS for the MIG and TIG welding processes. They come in different sizes and you wanta' research before you buy. If you get too small of one, you'll get real tired of refilling it all the time.

Defect - Something that ain't right with the weld. Main defects are Longitudinal Cracks, Porosity, Slag Inclusion, and the "Cardinal Sin" of welding…Undercut.

Depth of Fusion - How deep your filler metal penetrates into the metal from the surface.

Direct Current - DC welding is the smoothest welding producing the least amount of spatter. The current is flowing one way, from negative to positive. (Cathode to Anode)
It is similar to when you turn on a water hose and the water flows out. With DC the current ALWAYS flows the same direction. You can however, change your welding leads to change Polarity.

Direct Current Electrode Negative - Electricity flowing OUT OF the welding Rod or Wire is dispersed into the work piece therefore giving less penetration. About 1/3 of the heat is on the end of the rod and 2/3 on the work piece. This is what you want to use for thin gauge metals.

Direct Current Electrode Positive - Electricity flowing INTO the welding Rod or Wire and therefore putting more heat at the rod or wire end. This gives you 2/3 heat on the rod and 1/3 on the work piece, which gives greater penetration for thick metals because the arc force digs into the steel before depositing filler metal.

Ductility - Is the metal bending and staying bent without breaking.

Duty Cycle - This is how long a machine can run in a ten minute period of time before it overheats.

10% = 1 minute out of every 10.
20% = 2 minutes out of every 10.
On up to 100% which would run the full time without stopping.

For a machine in a factory or construction site you'd want a 100% duty cycle.
For your hobby workshop you might get by with 20 or 30%.

Even in the busiest factory there's gonna' be off time in a ten minute period. If you're stick welding, you might run a little over a minute. Then you're gonna' raise your hood, check out what everyone else is doing, think about what you're gonna' do that night, chip the slag, brush the weld, check what time it is, change rods, and FINALLY start back to welding.

Edge Joint - The outer edge of two plates butted up 90 degrees parallel to each other.

Edge Preparation - Before welding the edge of a plate or pipe, care is taken to ensure a sound weld. It may be torch cut or beveled, machined with a grinder, filed, or all three.

Electrode - Electrodes come either covered with flux, or just bare wire. In the field an electrode is called a "rod" in stick welding, and "wire" for Mig and Flux Cored Arc Welding.

There are MANY different types of electrodes.

In WWII bare rods were used that could only be used in the flat position. It was VERY easy to stick these rods, and I can only imagine how frustrating it must have been to use them. One day a guy noticed that a rusty rod he picked up welded better than the brand new ones.

Experimenting with different types of coatings like silicon and potassium, it was determined that flux on a rod not only helped it burn better, but produced a shielding gas that protected the weld pool from the atmosphere.

Electrode Holder - A hand clamp that holds a welding rod and conducts electricity out of the rod in DIRECT CURRENT ELECTRODE NEGATIVE, or into the rod in DIRECT CURRENT ELECTRODE POSITIVE.

Face - On plate or pipe welding there is a ROOT PASS, HOT PASS, FILLER PASS, and CAP. The root penetrates through the back of the plate, the cap is on the surface which you are welding, which is the face.

Fan: Welding machines have a fan to cool the machine down and keep it from overheating. (see DUTY CYCLE) Some fans run constantly, while others run "on demand" which means it comes on when necessary and clicks off when not needed.

(It is a good idea to blow out the welding machine with compressed air at least once a month. This keeps dust from accumulating and possibly interfering with the inside electrical workings. All machines have vent slots and each slot should be blown out.)

Ferrous Metal - Iron comes from ore that is mined from the Earth. See How Steel is Made. Ferrous means that the metal is iron, or iron with alloys.

Filler Metal - This is metal added to the weld pool. A weld can be made with or without filler metal. Thin gauge metal is sometimes welded by melting the two base metals together.

Flash Burn - This is a burn from the radiation produced from the ULTRA VIOLET rays from the welding arc. It can burn the skin similar to sunburn, and even blister the cornea. You don't realize it until hours later when it feels like someone is rubbing hot sand in your eyes.

Two of my students were welding too close to each other and I told them to move, but they said they were just fine. Yeah, what do I know? I've only been doing this 30 freaking years compared to their three or four months!

Welp, that night they were in the emergency room getting salve for their eyes and a nice $300 emergency room bill.

You should never be where you can see the welding arc light without protective lenses, even if it is just out of the side of your eyes. In my shop we announce loudly "WATCH YOUR EYES!" before striking an arc to warn you to cover your eyes.

Fillet Weld - The king of welds because it is used in so many applications, it is mostly used on Tee joints. . (See JOINTS.)

Two pieces of metal butted together at a 90 degree angle, a bead is run half way into each piece. Depending on the thickness, it could take one bead, or multiple beads TIED-IN to each other.

Fillet Weld Face - The surface or top of the weld.

Fillet Weld Leg - From the intersection of the joint to the end of the weld. There will be a leg for each plate.

Fillet Weld Toe - Is the end of the weld at the end of the leg. Again there will be one for each plate.

Fillet Weld Root - Where the weld begins at the intersection of the joined plates.

Fillet Weld Throat - The distance from the root to the face.

For the above FILLET WELD definitions, see Miller's Tig Welding page for a good illustration…
http://www.millerwelds.com/education/TIGhandbook/pdf/TIGBook_Chpt7.pdf

Flow Meter - The pressure in a SHIELDING GAS bottle can be up to 2400 lbs. per inch. The flow meter reduces this to a working pressure, usually around 20 to 25 cubic feet per hour.

Flux:
Cleans the surface and when burned makes a SHIELDING GAS that protects the weld POOL, or PUDDLE from atmospheric contaminants that cause DEFECTS.

Flux-Cored Arc Welding (FCAW) - Long thin flat strip is run through a series of dies until it begins to curl up on the sides. FLUX is then added and it continues through the dies until it is rolled into a tubular wire.

Similar to SOLID STEEL WIRE, it is rolled and used similar to MIG usually set to DIRECT CURRENT ELECTRODE NEGATIVE. When the wire is melted to become FILLER METAL, the FLUX burns and forms a SHIELDING GAS.

Therefore, no SHIELDING GAS is needed, so it can be used in drafty areas or even in the wind, unlike it's cousin MIG.

Free Bend Test - Also called a guided bend test, this is a destructive test. A coupon is cut from a test plate, the weld grinded, then the coupon (usually 1 ½ "wide by 7" long) is bent in a JIG. It is then VISUALLY INSPECTED for cracks and defects.

This is one way of demonstrating QUALIFICATIONS to become certified. Welding is one of the most demanding trades because the welder always has to show they are qualified.
I have 30 years of experience in the shop, Iron Workers Union, and education, yet if I went to a job on say, a power house, with a welder whose been in the field only a couple of years, I'd still have to take a test with them!

Critically demanding jobs require X-RAY qualifications which are non-destructive, but show everything!

Fumes - Whether you are a skilled JOURNEYMAN, or NEWBIE, you should always be careful of fumes when cutting and welding.

From GALVANIZED zinc fumes which make you sick, to more dangerous phosgene gas which can be emitted from the UV RAYS around some cleaning solutions, FUMES can be dangerous!

Always make sure you have proper ventilation, especially in confined quarters!

Fuse - If you purchase a welder to use around the house, make sure you have the proper fuse so you don't blow everything out. In older houses, make sure the wiring has been updated or you could cause a fire when they overheat.

Fusion - As stated in COALESCENCE, fusion is the melting and becoming one with the base metal or PARENT METAL you are welding grasshopper.

This is also a word for what the doctor wants to do to my ankle that I shattered when I fell three stories. Wants to take a chunk of my hip bone and fuse it to my ankle. Trouble is, it'd take longer for the hip to heal than the dang ankle! So…that little operation ain't gonna' happen. Heck, it only hurts when I'm awake anyway!

Galvanized - An electrochemical process where mild steel is hot-dipped into liquid zinc to make it anti-corrosive. I was surprised to learn it has been done for 150 years!
When you weld on galvanized steel you have to burn through the zinc coating first and it produces FUMES that can make you feel sick like you've been punched in the gut.
Drinking milk before, during and after welding is supposed to help, but proper ventilation and not breathing it at all is best.

Gas Metal Arc Welding (GMAW) - see "MIG"

Gas Tungsten Arc Welding - see "TIG"

Groove Weld - When a very strong weld is needed, such as where two columns are spliced together on a high-rise, it is important to get the maximum penetration and fusion. This is done by cutting a BEVEL so that you can weld solid from the ROOT, to the FACE of the PARENT METAL.

Heat Affected Zone - Something many welders do not consider, but they should. Anytime you weld on metal or steel, you are heating the area next to the weld. After it is heated, it cools at different rates depending on the temperature in the shop or field.
On construction projects in the winter, this can be very rapidly. Both the heating and cooling can affect the properties depending on what base metal you are welding on.
The heat affected zone on mild steel is usually no big deal. However, if you weld on cast iron, for example, without properly pre-heating and post-heating, it will crack right before your eyes.

Inverter - Relatively new, I first heard of them about 13 years ago. A power source for welding machines that is much more efficient than the normal transformers most machines use, and therefore much smaller units.

When I first started welding thirty years ago in a black iron shop, I used a welder that looked like a big atomic bomb with a box on top of it. It was at least four feet wide, two feet deep and about three feet tall.

Today they have machines that can do everything that one could, plus some and they're the size of a small suit case which is much more convenient for the shop and field.

Iron Workers - There are a couple of meanings here. The first is the union I belong too, the International Association of Bridge, Structural, Ornamental and Reinforcing Iron Workers. As the title suggest, we work on structures, everything from high rise office towers, to dams, power houses etc. After a 3 year apprenticeship, I became a structural welder. There are other gangs (crews) such as the Raising Gang, Plumb Gang, Bolt-up Gang, and Miscellaneous Gang. Although I've worked on them all, I spent most of my time on various Welding Gangs seeing as how welding is my true love!

This is also the term for a machine, both HUGE ones, and those small enough to be portable on jobs. It can shear metal, cut angles, and punch holes. You're gonna' invest a minimum of around a couple of thousand for a smaller model. Don't even want to think what the big ones cost.

Intermittent Weld: A very common mistake in welding is welding it too much! A lot of welders, especially those new to the trade, figure "the more the weld the better it'll hold." Well, it AIN'T true! Many times one or two inches of weld every couple of inches will hold just as good as a continuous weld.

On most jobs, whether in the shop or field, the welds will be on a blueprint so that you will know just what to do. Engineers determine what kind of weld is the best for the joint involved.

There are two types of intermittent welds. I'll give an example from a black iron fabrication plant I once worked at:

1) "Chain" On a twenty foot beam, we would find the center at say, ten feet. We would mark two inches, one inch on each side of the center. Then, from the center of that weld, we'd make a mark twelve inches away. On that mark, we'd measure one inch on each side. That way we were measuring from center to center on each weld. In most construction, just about everything is measured from center.

On the other side of the beam, we'd mirror the marks of the first side.

Obviously, the ends of the beam would not come out right in sequence, so it was important that we made sure and put two inches on each end even if it was right next to the other two inch marks we had made.

2) "Staggard" After making the marks on one side of the beam, we would place the other side in-between the marks on the first side.

These welds are strong enough to hold and it is overkill to weld these joints solid. When overzealous welders over weld, they are screwing up in several ways…

1. They are heating the base metal which can change its properties adversely.
2. They are spending unnecessary time. In the shop and field "Time is MONEY!"
3. They are wasting materials by using rods which are costing more and more each year.
   

Jig - Jigs hold the metal or steel you are working on in place as you are fabricating. They can be steel clamped with a vice or C-clamp, bolts tack-welded to a table, or very elaborate frames. Positioners in large fab shops hold the work piece, spin, rotate, or revolve so that you can weld in the flat or horizontal position.

Joint - Intersection where two different sections of PARENT METAL meet. To be listed under WELDING JOINTS. On a power house, they'd ask how many joints we welded each day.

There were many different types such as beam to beam, beam to column, x braces etc. Although it was not an accurate account, it gave the foreman an idea of what was getting done.

Excellent chapter on JOINTS is Miller's Tighandbook...
http://www.millerwelds.com/education/TIGhandbook/pdf/TIGBook_Chpt7.pdf

Keyhole - When welding an open butt, or open groove weld JOINT with STICK, MIG or TIG, a "keyhole" will open up. When the sides of the plate burn away on each side of the WELD POOL a hole is formed which allows for good TIE IN and PENETRATION.

The keyhole must not be allowed to grow too large or the WELD POOL will waterfall out the back of the joint.

If the keyhole grows too large, stop welding immediately, let the plate cool and make the proper adjustment to correct the problem. (Too much heat, wrong rod angle, or staying too long in the puddle may be the cause.)

Labor Unions - A good site listing trade unions is http://www.trcp.org/unions.aspx.
In my experience as an Iron Worker, I'd say you'd have the most chance of welding in the following…

Boilermakers

Iron Workers

Pipefitters

Pipeliners

Sheetmetal Workers

Leads - These are the lines from the machine to what you are welding that carry the current. They are lots of copper wires woven into one to conduct electricity, then covered with a non-conductive rubber or plastic wrap.

It is important to make sure there are no rips or a tear in the leads exposing bare wire which could arc on a grounded surface. Besides being a shock or fire hazard, it would especially be bad if it came in contact with a pressurized gas bottle!

Liquidis - A word that makes you sound smart when you mean the lowest temperature that steel or metal is liquid. Guess what "solid" is called? (See SMART TALK)

Machine Welding - Equipment performs the weld while a person watches to make sure it is working right. They will also visually inspect the completed weld. Whether with robotics, or machine welding, most companies prefer someone who has actually welded in the field because they have a "feel" for it.

Journeyman welders can actually feel the weld TIE-IN to the steel. When I'm STICK WELDING with 7018, I can literally feel the rod give ever so slightly as it coalesces with the steel.

Manual Welding - A person is doing the actual welding. In SMAW (stick) they are holding the STINGER and manipulating the WELDING ELECTRODE to control the WELD POOL. In MIG they are using a Mig gun feeding wire to do the same. In TIG they're using a torch and manually feeding a filler rod.

Melting Rate - How much of the rod (electrode), wire, or TIG rod is melted in a certain amount of time.

Melting Point - Ahhhh grasshopper, this is where the metal goes from SOLIDUS to LIQUIDUS. See SMART TALK.

MIG (GMAW or Gas Metal Arc Welding)- It may be technically called GMAW, but in the shop and field all I ever heard was Mig.

Mig welding uses a solid steel wire rolled up on a spool and fed through a welding lead with a liner in it. Drivers push, pull or both to feed the wire through the lead to the WELDING GUN.

It uses several different mixtures but the most I've used is either stratight carbon dioxide, or a mixture of the inert gas argon and CO2 (75/25 is common. 75% Argon, 25%CO2) to shield the weld PUDDLE from the atmosphere.

Page 2 - Basic Welding Terms

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