What Is 7018 Welding Rod Used For? A Complete Guide

A farmer in rural Nebraska finds a crack in the frame of his older loader, and the nearest welding supply house is 90 miles away. He grabs a box of 3/32-inch 6013 rods because they are on the shelf. The bead looks fine, but six weeks later the crack is back — right next to it. The problem wasn’t his technique. It was the number on the package. That four-character code, E7018, is the single most important piece of information printed on a stick electrode box, and it tells you what the rod is actually for.

What Is 7018 Welding Rod? Decoding the Four Digits

7018 welding rod is a low-hydrogen, iron powder coated stick electrode for shielded metal arc welding (SMAW) of carbon and HSLA steel. It is the default electrode for structural fabrication, code work, and heavy field repair because it is approved for every welding position except vertical down, it runs on AC or DC electrode positive, and it produces an as-welded deposit with a 70,000 psi minimum tensile strength. That is the short answer. The rest of this section takes apart what each character on the box actually promises you, because the number is not a brand code, it is a specification written in four characters.

The Classification, Digit by Digit

Carbon steel arc welding electrodes are classified under AWS A5.1, the specification for carbon steel arc welding electrodes. Here is what E7018 says:

Character	Meaning	What it means in the shop
E	Electrode	Identifies a consumable stick electrode as opposed to a filler rod, wire or tube.
70	Minimum tensile strength of the as-welded deposit	70,000 psi, roughly 480 MPa, measured on the deposited weld metal, not on the parent metal.
1	All-position electrode	Approved for flat, horizontal, vertical up and overhead welding. The only position it is not rated for is vertical down.
8	Coating type and current type	Low-hydrogen iron powder coating, medium penetration, usable on both AC and DCEP.

Two quick housekeeping notes. “7018” and “E7018” mean exactly the same electrode, and “rod,” “electrode” and “stick” are interchangeable shop words for the same consumable. If you are working internationally, the same electrode is also classified E5018 under the Chinese GB/T 5117 standard, so a box bought from an overseas supplier is not a mystery product. Many of the physical differences between electrode families are laid out in our all position welding rod guide, which is worth a read before you buy.

What “Low Hydrogen” Actually Means

Low hydrogen is not a marketing phrase. It describes a coating that is formulated and baked at the factory to pull moisture out of the electrode before it ever reaches your shop, and then kept sealed so it cannot take moisture back in. The result is a deposit containing very little diffusible hydrogen, and that matters because diffusible hydrogen is the root cause of hydrogen-assisted cracking in higher-strength steels. Miller’s technical explanation of the hydrogen problem in welding is the clearest explanation of the mechanism we have seen. Cellulosic electrodes like E6010 and E6011 do the opposite: they are deliberately wet with sodium silicate, which gives them the deep penetration and fast slag that pipeline root passes rely on, and they carry far more hydrogen into the weld.

Lincoln Electric’s technical guide to low-hydrogen SMAW electrodes goes deeper on the coating chemistry if you want the detail.

What the Iron Powder Is Doing

Some low-hydrogen electrodes use a wet coating, and some bake iron powder into a dry coating. When iron powder is in the mix it does three useful things: it raises the deposition rate so you lay down more metal per inch of travel, it smooths and stabilises the arc, and it cuts spatter. That is why a good 7018 bead tends to look cleaner and more uniform than a classic cellulosic bead, and why it is a good general-purpose rod for someone who does not want to babysit the puddle. The trade-off is medium penetration rather than the deep penetration of a cellulosic rod, which is exactly why pipeline root passes are still done with E6010 and not with 7018.

The Extra Characters on the Box

Base classification is only the beginning. A box might read E7018, E7018-1, E7018-H4R, E7018-B1 and so on. The suffixes matter:

• H4 means 4 ml or less of diffusible hydrogen per 100 g of weld metal. H8 means 8 ml or less. When a code calls for controlled diffusible hydrogen, it names one of these two.
• -1 raises the Charpy V-notch impact requirement to 20 ft-lb at -50 degrees F. A standard E7018 is qualified at 20 ft-lb at -20 degrees F.
• R means the manufacturer has tested the electrode for moisture resistance after nine hours of exposure at 80 degrees F and 80 percent relative humidity.

Typical Mechanical Properties

Tensile strength	70 ksi (about 480 MPa) minimum
Yield strength	58 ksi (about 400 MPa) minimum
Elongation	22 percent minimum
Fillet weld test	AWS A5.1 requires E70XX electrodes to pass a three-fillet-weld test at 58 ksi minimum shear strength
Diffusible hydrogen	H4 or H8 options, in ml per 100 g of weld metal

Finally, the one distinction worth memorising: cellulosic E6010 and E6011 are fast and deep-penetrating but very high in hydrogen, while acid-rutile E6013 is a DC electrode with quick-slagging, shallow penetration that is popular for thin sheet and hobby work. E7018 sits between them in penetration, sits far below them in hydrogen, and is the only one of the three that is code-friendly in every position except vertical down. If you want the wider context on why SMAW keeps winning jobs that other processes lose, our piece on the advantages of stick welding covers it. When you are matching to higher-strength or alloy base metal, take a look at alloy steel welding electrodes for the next steps up the strength ladder.

Where 7018 Rod Is Actually Used: From Structural Steel to Field Repairs

E7018 earns its keep wherever carbon steel or HSLA steel is being joined and the joint has to resist cracking days later. Its AWS classification under A5.1 covers the work most people picture when they think of stick welding, but the range is wider than most welders assume. A fab shop building pressure tanks and a ranch hand patching a gooseneck hitch are both legitimate 7018 jobs.

Application	Why E7018 fits
Structural steel fabrication (A36, A514, other HSLA)	Structural steels such as A514 demand filler metal with 70,000 psi minimum tensile strength, and AWS-classified E7018 meets that specification.
Structural erection and field erection	All-position capability handles a beam going up in any orientation, and the rod tolerates site fit-up gaps, light rust and weather.
Bridges and bridge repair	Low-hydrogen deposits, and many bridge specifications call for controlled diffusible hydrogen.
Boilers and pressure vessels	ASME code work routinely limits the hydrogen a filler metal can feed into a joint.
Storage tanks	Field-erected and shop-welded tanks rely on the same crack resistance for seal and structural welds.
Pipe and pipeline fill and cap passes	Matches 70 ksi HSLA pipe and satisfies the hydrogen limit in pipeline codes.
Shipbuilding and offshore	Lincoln Electric markets E7018 for steel structures, field erection, plants and rigs, which is exactly this work.
Mining, rail and heavy equipment repair	Buckets, booms, wear plate, track frames and locomotive steel are thick, dirty carbon steel that rewards a tough, forgiving deposit.
Farm and ranch equipment	Implements, hay equipment and frame repairs get no code paperwork and no shop help, so the rod has to work for itself.
Hitch hardware and general fab maintenance	Small bracket and mount welds in mild steel, plus the default filler for anything in carbon steel nobody wants to think about twice.

Why low-hydrogen makes it the code default

Hydrogen-assisted cracking needs three things at once: a susceptible microstructure, residual stress and hydrogen. Code writers attack the last one through the filler metal, which is why structural, pressure vessel and pipeline specifications commonly restrict or outright prohibit electrodes with high diffusible hydrogen. E7018’s baked iron powder coating puts it under the limits those codes set, so when a drawing calls for E7018 you use E7018. For a shop that wants the advantages that SMAW still offers over newer processes, one rod that satisfies most code filler metal requirements is worth a lot of shelf space.

The pipeline caveat nobody skips

Here is where 7018 stops being the answer. Miller Electric points out that low-hydrogen stick electrodes such as E7018 do not offer the penetration and performance characteristics of cellulosic electrodes, and are therefore generally not acceptable for root-pass pipe welding. In transmission pipeline work, cellulosic E6010 remains the standard root-pass rod because its deep, digging arc gets full penetration and handles the ovality and fit-up problems of real field joints. E7018 then fills and caps the joint, where its low-hydrogen deposit is exactly what the code wants.

What E7018 is not for

E7018 is a carbon and low-alloy (HSLA) electrode. It is not a stainless, aluminium or nickel-alloy electrode, and putting it on those metals is a bad idea for reasons that reach beyond strength matching.

• Aluminium: needs its own family, including E4043 and E5356, or MIG/TIG processes. See our aluminium MIG welding guide for the process side and the aluminium cleaner guide for prep, because oxides and heat are the real enemies.
• Stainless and heat-resistant steel: use E308L, E309L or E312. A carbon steel deposit on stainless will eventually rust and may fail.
• Cast iron: use nickel-iron (E Ni-CI) electrodes or brazing, not 7018.
• Copper and brass: use E CuSi. Copper conducts heat far too well for a 70 ksi steel rod.
• Galvanised steel: weldable in principle, but the zinc fume requires proper extraction or respiratory protection, and many shops avoid it altogether.

Three jobs, three very different shops

A structural ironworker tying off a bridge gusset on a cold morning is running E7018 because the A514 plate demands 70 ksi filler and the job spec names a low-hydrogen classification. Flat and overhead, stringer beads, no excuses.

A repair shop rebuilding a loader bucket reaches for the same rod for a different reason: thick abrasion-resistant plate, dirt, unknown heat input, a shop schedule. The all-position deposit and forgiving iron powder coating mean one rod covers the rebuild whether it sits flat on a bench or goes overhead under the machine.

A homeowner fixing a trailer hitch is doing nothing exotic. Mild steel bracket, a couple of inches of fillet weld, a driveway in the evening. E7018 is simply the strongest general-purpose carbon steel rod in the box, and the all-position rod selection guide walks through the rest of the options.

Put those three together and the pattern is clear. E7018 is not a specialty rod. It is the rod you reach for by default on carbon and HSLA steel, from the code job to the hitch, and the choice is only wrong when the metal is not steel or the position is vertical down.

Why ‘Low Hydrogen’ Decides Whether Your Weld Holds

Some welds fail quietly. The bead passes inspection, looks clean under a wire brush, and the joint holds for a while. Then it opens up hours or days later, usually with a crack running alongside the bead through the heat-affected zone. That failure mode is hydrogen-assisted cracking, also called HAZ cracking, delayed cracking, or cold cracking. It is the single biggest reason the E7018 classification exists, and it is why a rod that cost more per pound is routinely specified on structural, pressure vessel, and pipeline work.

Understanding it starts with a simple point from Miller’s guide to the hydrogen problem: the crack does not appear at the arc. It develops after the weld is finished, sometimes hours later, sometimes several days later, as hydrogen works its way out of the weld metal and pulls against the surrounding steel. That delay is what makes it so expensive. A repair that looked perfect can fail later and take a whole assembly down with it.

Three Conditions That Must All Be Present

Hydrogen cracking never happens because of one cause. It needs three conditions to line up at the same time, in the same joint, at the same time:

1. Hydrogen in the weld metal, typically absorbed from moisture in the electrode coating, the base metal, or contamination in the joint.
2. A crack-susceptible microstructure, which usually means hard, brittle martensite formed in the heat-affected zone of a higher-carbon or higher-strength steel that cooled too fast.
3. Residual stress, the pulling force left in the joint by the welding process itself as the metal cools and shrinks.

Remove any one of the three and the crack will not form. That is the whole engineering logic behind low-hydrogen electrodes: they do not change the stress or the microstructure, they simply starve the crack of its fuel. It is also why the choice of rod becomes more critical as the base metal gets stronger. The same E7018 bead that is perfectly safe on A36 mild steel can be a liability on a high-strength or high-carbon joint, because harder steel produces a more crack-susceptible microstructure in the first place. If you are matching fill or cap passes to stronger base metal, our guide to alloy steel welding electrodes covers how the classification changes.

Cellulosic Versus Low Hydrogen: The Numbers Behind the Designation

Diffusible hydrogen content is measured in millilitres of hydrogen per 100 grams of deposited weld metal, and the difference between electrode families is not subtle.

Electrode classification	Coating type	Diffusible hydrogen
E6010 / E6011	Cellulosic	Well above 16 ml per 100 g
E7018 standard	Low hydrogen, iron powder	Up to 16 ml per 100 g
E7018-H4	Low hydrogen, iron powder	4 ml per 100 g or less
E7018-H8	Low hydrogen, iron powder	8 ml per 100 g or less

Cellulosic rods such as E6010 carry the highest hydrogen levels of any commonly used filler metal, which is exactly what makes them so good at root-pass pipe welding and exactly what makes them unsuitable for code-critical fill and cap passes on stronger steels. Low-hydrogen electrodes, as Lincoln Electric explains, are baked and formulated to limit that hydrogen at the source. When a specification calls for controlled diffusible hydrogen, it is specifying one of the H4 or H8 designations on the box.

The Sponge Analogy

Think of the coating on a low-hydrogen electrode as a dried sponge. It is designed to carry only what it needs, and it delivers a predictable, low-hydrogen weld every time. A sponge that has been left out in the rain is still a sponge, but it now holds water. An E7018 rod that has sat open on a job site has done exactly that. The absorbed moisture decomposes in the arc, feeds hydrogen into the weld pool, and the low-hydrogen classification you paid for evaporates. Hobart’s handling and storage guidance explains why the rod ships in hermetically sealed packaging in the first place.

Where the Hydrogen Actually Comes From

The rod is only one source. In practice, most hydrogen problems trace back to three places:

• Damp consumables. Electrodes that have been out of their packaging, left in a truck bed, or handled with sweaty bare hands. Miller specifically advises handling filler metals with clean, dry gloves, because sweat and skin oils transfer moisture and contaminants straight onto the coating.
• Contaminated joint metal. Cutting oils from bevelling, paint, mill scale, rust, dirt, and any organic material in the joint. Miller advises grinding both the inside and outside surfaces of pipe one inch back from the joint to remove cutting oils, paint, and organic contaminants before welding.
• Heat input that creates the wrong microstructure. Too little preheat on a heavy or cold joint, or a travel speed fast enough to quench the heat-affected zone into hard martensite, gives the hydrogen something brittle to attack.

The takeaway is unglamorous but important: stick welding’s reputation for holding up in the field rests on details like dry storage, clean gloves, and a ground-clean joint as much as it rests on the machine settings. Match the rod to the joint, then keep the rod dry, and the weld stands a much better chance of still being there years later.

Choosing the Right 7018 Diameter and Setting the Amps

Numbers beat guesswork. A 7018 electrode runs across a fairly wide band of amperage, and a 20 amp error shows up plainly in the bead. Too little and you get a cold, half-melted track that peels off the plate. Too much and you get undercut, melt-through on thin material, and a bead that looks like a melted rope. The good news is that the usable range for every diameter is well documented, so you can start closer to right than most people expect.

Amperage by electrode diameter

These are the operating ranges Hobart Brothers publishes for 7018 electrodes, and they make a solid working reference for anyone picking up a box at the supply house:

Electrode diameter	Operating range	Where it fits
3/32 in.	80 – 100 A	Thin sheet, light structural, repair work
1/8 in.	90 – 150 A	General purpose, plate up to 1/4 in.
5/32 in.	110 – 230 A	Heavy plate, all-position structural work
3/16 in.	150 – 300 A	Plate 1/4 in. to 1/2 in., fabrication
7/32 in.	220 – 350 A	Heavy plate, thick sections, pipe
1/4 in.	270 – 380 A	Heavy fabrication, fillet weld repair

Two rules matter more than the table itself. First, the operating parameters printed on the box for the electrode you bought take priority over any generic chart, because coatings and formulations differ between manufacturers. Second, on a coded job the WPS on the job site overrides everything, including the data sheet. If the procedure says 140 amps, you run 140 amps.

Matching rod diameter to plate thickness

The working rule of thumb is simple: use a 1/8 inch rod for plate up to 1/4 inch thick, and step up to 3/16 inch for plate between 1/4 and 1/2 inch. A 5/32 inch rod is a useful all-round compromise if you weld a mixed pile of material and do not want to buy half a dozen boxes.

Here is the part people get wrong. A bigger electrode does not just handle thicker metal, it puts more heat into the joint per inch of travel. That is why you step up in rod diameter on a thick joint instead of simply turning up the machine. Running a 1/4 inch rod at 380 amps on a 1/8 inch plate will burn through it before you finish the pass. A smaller rod lets you control the heat input and still get fusion.

You will also hear a rough formula quoted as one amp per thousandth of an inch of material thickness, so 1/4 inch plate would suggest 250 amps. Treat that as a starting point for a trial weld on a scrap coupon, nothing more. It ignores joint geometry, travel speed, position, and the fact that pass size drives heat input as much as current does. The data sheet and the WPS are the authority, and the coupon is reality.

Running your first bead

1. Start in the middle of the range, not at the top or bottom. If the range is 90 to 150 amps, begin around 120.
2. Make a test coupon on scrap of the same thickness and grade as the real joint.
3. Check fusion and profile. Good fusion means you can break the coupon and the base metal tears rather than the bead lifting off. Profile means the bead sits flat, slightly crowned, with clean toes and no undercut.
4. Adjust in 10 amp steps and repeat until the bead looks right, then write the number down.

Hold a short arc, roughly the length of the electrode diameter, and keep the work angle near 90 degrees. If you are new to the process, a refresher on why stick welding still wins on dirty, remote jobs is worth the read.

Bead width geometry

For flat and horizontal welding, target a bead width of about two and a half times the core wire diameter. A 3/32 inch rod has a core of roughly 0.036 inch, so a clean bead should land near 0.09 inch wide. For vertical up, go a little wider, around two and a half to three times the core diameter, to help the puddle track upward instead of running down.

Wider than that and you are asking for trouble. An overwide bead traps slag underneath, creates lack of fusion at the edges, and compromises the integrity of a structural weld. Slag inclusions are not a cosmetic issue, they are crack initiation sites. If you want a wider pass, add another stringer bead rather than stretching the one you are welding. The all-position rod guide covers how bead shape changes as you move between flat, vertical and overhead positions.

One more practical point on diameter: heavier electrodes and higher amperages are a matched pair, but so are heavier electrodes and larger workpieces. On thinner material, a smaller rod at the same amperage is what keeps your heat input under control and your bead shape clean. Choose the diameter that matches the joint, then set the machine inside the range for that diameter.

Polarity, Welding Positions, and Technique for 7018

Same rod, same machine, same amperage. Change the polarity or the position and the bead can change completely. These are the operating details that separate a good 7018 weld from a mediocre one, and they are where a lot of “bad rod” complaints actually come from.

Polarity: AC or DC electrode positive?

E7018 runs on either AC or DC electrode positive (DCEP). There is a preference though. Low-hydrogen electrodes are designed to run best on DCEP, and manufacturers particularly recommend that setting at 5/32 inch and smaller, where the arc is hardest to hold steady. Lincoln Electric’s guide to low-hydrogen SMAW electrodes makes the same point: run these rods on DCEP whenever you can and treat AC as the fallback.

Polarity changes where the heat goes. On DCEP, the deeper penetration sits at the work, the electrode end stays cooler, and current flow into the job stays constant. That constant flow is why DCEP gives you easier arc control and a flatter, more uniform bead profile. Set your machine to DC, then confirm the electrode lead is on the holder and the work lead on the workpiece clamp. Swap those and you have DCEN, which you will notice immediately: the electrode runs hot, spits, and lays down a rough, heavy bead that behaves nothing like the rod you’re holding.

AC is the more forgiving option when a generator is the only power source on the job, and that convenience is real. The trade-off is arc behaviour, since alternating current flips the arc repeatedly.

Walking through the four positions

Flat position. The friendliest of the four. You can see the arc and the puddle clearly, travel speed is faster, and defects are easier to spot and fix while the arc is live. Drag the electrode along the joint rather than stabbing it, hold a tight arc length, and let the puddle lead the travel slightly.

Horizontal position. Gravity is now working against you, and the two things that cause most defects here are travel angle and puddle control. Too much travel angle pulls the arc toward the leading edge of the joint and cuts into the base metal, which is undercut. Keep the electrode over the puddle, keep the bead size modest, and resist the urge to rush, because a sagging or wandering puddle is what produces cold lap and slag on this position.

Vertical up. This is the position people practise most and get right least often. Hold a 3 to 5 degree leading angle with a slight weaving motion, and keep the puddle small. A small puddle that solidifies between passes is far easier to control than a big one that runs down the joint. Let each bead set before you move the electrode up.

Overhead position. Everything runs against gravity, so the electrode usually sits on a harness rather than your hand for any length. Use short beads, keep the work moving, and let the puddle solidify before you step in to clean slag. Expect to adjust your amperage slightly within the range on the Hobart Brothers 7018 amperage data to suit the position.

Technique habits that pay off

• Drag, don’t stab. Drawing the electrode along the joint gives a wider, flatter bead with better fusion than a stabbing motion.
• Keep a tight arc in flat and horizontal work. A long arc raises spatter, widens the bead, and increases the chance of nitrogen-driven porosity.
• Keep the electrode almost on top of the puddle. This is the single most effective anti-porosity habit, because the puddle is shielding itself.
• Prefer stringer beads. Wide weaves on 7018 invite slag inclusion, since the coating’s iron powder and rutile form slag that a wide weave buries. Weave narrow or not at all.

The practical tip is simple: match your technique to the position rather than using one habit everywhere, and read the WPS before you strike an arc. If you are still building your process knowledge, the all position welding rod guide breaks down what each classification actually expects from you, and the stick welding advantages overview covers why field crews still choose this process despite the alternatives.

7018 vs 6013 vs 7024 vs 6010: Choosing the Right Electrode

The easiest way to pick the wrong stick electrode is to pick it by strength alone. Two rods can both read “70 ksi” on the box and still be completely wrong for the joint in front of you, because classification codes hide three other decisions: what coating you are welding with, which positions you are allowed to hold the electrode in, and how much hydrogen the deposit can carry. Get those right and the choice becomes fairly simple.

Electrode	Min. Tensile	Coating / Process	Approved Positions	Current	Penetration	Hydrogen Class
E7018	70 ksi	Low-hydrogen iron powder	All except vertical down	AC or DCEP	Medium	Low (H4 / H8 options)
E7024	70 ksi	Iron powder	Flat and horizontal only	AC or DCEP	Medium	Low, but check the data sheet
E6013	60 ksi	Rutile	All positions	DC only	Deep	Not a low-hydrogen electrode
E6010	60 ksi	Cellulosic	All positions	DC only	Deep	High (highest of common filler metals)
E7018-AC	70 ksi	Low-hydrogen iron powder, AC-optimised	All except vertical down	AC or DCEP	Medium	Low
E8018-B2 / E9018	80 / 90 ksi	Low-hydrogen alloy, Cr-Mo or higher alloy	All except vertical down	AC or DCEP	Medium	Low

What the table does not tell you

E7024 is the closest thing to a drop-in lookalike for E7018, and that is exactly where it gets people. It carries the same 70 ksi minimum tensile strength and the same iron powder coating family, but it is approved for flat and horizontal positions only. That single limitation changes how it is used. E7024 is built for fast fill and high deposition rate, so it is a favourite for long seams in heavy plate lying flat on a table or on a bench. The moment you need vertical or overhead capability, it is off the table. It also runs a higher iron content into the deposit, which reduces ductility and can raise hot cracking risk in restrained joints, so it does not carry the same approval profile in structural codes. You can see the position-by-position breakdown in our all position welding rod guide.

E6013 is the classic hobby-shop and thin-sheet rod. It is 60 ksi, rutile coated, DC only, and it runs a hot, fast arc with deep penetration and slag that peels off almost on its own. What it is not is a low-hydrogen electrode, and it adds little or no iron to the deposit, which is why it is frequently chosen for galvanised steel where you do not want to dilute the zinc coating further. It is an excellent rod for a gate, a shelf bracket or a trailer light mount. It is the wrong rod for a bridge gusset or a pressure vessel.

E6010 is the pipe welder’s root-pass rod. Cellulosic electrodes like E6010 and E6011 have the highest hydrogen content of the commonly used filler metals, as Miller explains on the hydrogen problem. That high hydrogen is exactly what makes them so good at root passes: the deep penetration and fast travel come from an arc that behaves very differently from a low-hydrogen electrode. The price is that they are not acceptable for code-critical fill and cap work on higher-strength steels.

E7018-AC is simply the 7018 recipe tuned for alternating current, with extra arc stabilisers in the coating so the arc stays stable as current reverses. Use it when the only power source is a generator, or when you are welding on unfamiliar equipment and want a forgiving stick. E8018-B2 and E9018 step the strength up to match higher-strength base metal; the suffix tells you the alloy family, and our guide to alloy steel welding electrodes breaks down those B-designators further.

Reading the extra characters on the box

The four digits are only the start. E7018 is the AWS classification; a plain 7018 on a consumer box usually means the same electrode, and some manufacturers print 7018-1 for the low-temperature impact option. H4 and H8 state the diffusible hydrogen ceiling, and the R means the manufacturer has tested the electrode for moisture resistance after a defined exposure. A B1 or B2 suffix indicates a chromium-molybdenum or similar alloyed coating intended for higher-strength base metal. A single dash can carry several of these together, for example 7018-H4R.

When the specification wins

If the drawings or the job specification name a classification, that is the end of the discussion. Substituting a different electrode without written engineering approval is a code violation, not a shortcut, and it can void the qualification of the welder who made the joint. AWS has authored more than 350 standards for welding practices and procedures, and each discipline has its own filler metal rules:

• AWS D1.1, the Structural Welding Code for Steel, among the most referenced codes in the world, sets its own filler metal and qualification requirements.
• AWS D1.5 governs bridge welding, with position and hydrogen limits that differ from building work.
• ASME BPVC Section IX governs welding and brazing qualification, while B31.1 and B31.3 set filler metal rules for power piping and process piping.
• API 1104 governs pipeline welding, including the root-pass practice that keeps cellulosic electrodes in the pipe trench.

A decision rule that works

• E7018 when the joint is code work, when the base metal is HSLA or higher-strength carbon steel, or when you need to be able to weld in any position including overhead.
• E7024 when you are filling long flat or horizontal seams in heavy plate in one position and you want the deposition rate.
• E6013 for thin mild steel, galvanised work, and non-code hobby and farm repair where a fast, forgiving rod matters more than hydrogen control.
• E6010 for the root pass on pipe, then switch to E7018 for fill and cap on code work.

Most of the time, once you stop reading the box like a price tag and start reading it like a spec sheet, the right electrode announces itself.

Storing 7018 Electrodes: Keeping the Low-Hydrogen Promise

Storage is not housekeeping. For a low-hydrogen electrode it decides whether the classification on the box is still true. That rating is a property of the coating, and the coating is hygroscopic: it drinks moisture from the air and holds it. A box of E7018 left open on a job site slowly reloads with the hydrogen the classification was designed to exclude. The print still says E7018, but the metal no longer performs as described.

That is why E7018 ships in hermetically sealed packages. The seal is not convenience, it is the classification. Keep it intact until the moment you weld from it.

The Storage Hierarchy

• Best: a hermetically sealed container with desiccant, or an electrode holding oven at the manufacturer’s holding temperature.
• Acceptable: original sealed packaging, indoors in a dry, climate-controlled room, off the floor and away from exterior walls.
• Unacceptable: an open box, a truck bed, a shed, a job trailer, or a shop where the box has been open for weeks.

Miller is blunt about it. Low-hydrogen electrodes of the EXX18, EXX15 and EXX16 classifications, such as E7018, should always be stored in hermetically sealed containers or in electrode ovens, and you should follow the manufacturer’s recommendations for storage and reconditioning. Miller explains the mechanism in their article on the hydrogen problem.

Typical oven practice is straightforward: bake low-hydrogen electrodes at roughly 250 to 300 degrees Fahrenheit for a manufacturer-set period, then hold them at a reduced temperature between uses. That describes the practice, not a recipe. Exact temperatures and hold times must come from the data sheet in your hand.

And do not overdo it. Hobart Brothers notes that frequent reconditioning can degrade the outer coating and minimize shelf life, so a rod baked five times can be worse off than one baked once, properly. Their guide to product handling, storage and packaging covers reconditioning intervals and container types.

Job sites add their own rules. Codes commonly dictate how long a stick electrode package may remain open and how often it can be reconditioned, and those requirements come from the welding procedure specification and the governing code, not habit. If the work falls under AWS D1.1, D1.5, ASME Section IX, B31.3 or API 1104, read the filler metal and storage clauses before you open a box.

Handling Matters as Much as Storage

• Use clean, dry gloves. Sweat and shop oil transfer straight onto the coating.
• Never touch the coating with bare, sweaty or oily hands.
• Keep rods in their original packaging until you use them.
• Minimise moving electrodes from cold to warm environments. Condensation on a cold electrode carried into a warm shop is another source of weld hydrogen.
• Let cold rods warm in the sealed package before opening. A package pulled off a truck at 20 degrees into a 70 degree shop goes damp in minutes.

Storage gear, sealed pails and holding ovens are consumable supply, so shop your welding supply house the way you shop filler metal. A welding supply buyer’s guide helps you compare what is on the shelf. Some links in this section are affiliate links and we may earn a commission if you buy through them.

Storage Checklist

Run this at the start of every job:

• Package sealed, in date, lot number recorded?
• In a sealed container with desiccant, or an oven at the correct holding temperature?
• Off the floor, away from damp walls, exterior doors and chemicals?
• Opened boxes labelled with the date opened and rod size?
• Reconditioning done only per the manufacturer’s data sheet, and logged?
• Clean, dry gloves in use, no bare-hand contact with the coating?
• Cellulosic electrodes stored separately, at room temperature, never oven-dried?

A low-hydrogen electrode left open on a job site is not one any more, no matter what the box still says. Storage is not the boring part of the process. It is the part that keeps the classification true.

Common 7018 Mistakes and How to Fix Them

Get a good weld with a 7018 and the job is basically done. Get a bad one and the cause is usually hiding in plain sight. Lincoln Electric reports that porosity and cracking are the two most prevalent defects seen when welding with E7018 low-hydrogen electrodes. Neither usually means the rod is wrong: they trace back to storage, joint cleanliness, and heat input.

Porosity: gas bubbles in the deposit

Porosity shows up as pinholes, craters, or a spongy root pass. Moisture absorbed into the coating flashes to hydrogen at arc temperature and gets trapped in the weld metal. The same thing happens when the joint drags cutting oils, paint, mill scale, rust, or dirt into the pool, all documented sources of hydrogen and contamination.

Five causes cover almost every case: a damp electrode, sweaty or oily gloves, an arc stretched too long, a draft blowing the shielding gas column off the puddle, and contaminated base metal. Each fix is direct: store rods dry, handle them with clean gloves, hold a tight arc, screen the work from wind, and grind the joint back to clean steel.

Hobart Brothers recommends a tight arc length in flat and horizontal welding, keeping the electrode almost on top of the weld puddle, to minimise porosity. A longer arc means more air and more nitrogen in the column.

Cracking: two very different problems

Cracks split into two families that need opposite responses. Hydrogen cracking, also called cold or delayed cracking, shows up hours or days after the weld looks perfect, driven by hydrogen combined with restraint and a crack-sensitive microstructure. That is why hydrogen control matters so much on this rod. Damp rods or an oily joint are the usual triggers. The cure is dry consumables, a clean joint, and preheat on heavy or cold plate.

Hot cracking happens while the weld is solidifying and comes from overheating or from a joint that is too restrained. Control heat input, keep beads smaller, and preheat thick sections to slow the cooling rate.

Undercut: a groove along the toe

Too many amps, an arc held too long, too much travel angle, or dragging the electrode too fast will all dig a channel along the edge of the bead. Drop the amperage a step, shorten the arc, hold a 10 to 15 degree travel angle, and slow down enough to watch where the puddle sits.

Slag inclusion

Slag trapped under the bead usually comes from wide weave beads, the wrong electrode angle, or rapping slag too hard between passes. Use stringer beads, hold the electrode angle correct, and chip slag with a light tap rather than a hammer blow.

Lack of fusion and cold lap

When the bead sits on the plate instead of melting into it, you have too little heat, too fast a travel speed, an oversized bead, or dirty mill scale in the joint. Add amps or slow down, size the bead to the joint, and grind back to bare metal before welding.

Spatter and dirty beads

Heavy spatter and a black, sooty bead point to excessive amperage, a long arc, or wax and oil on the steel. Trim the amps, tighten the arc, and degrease first. If the work is galvanised, the zinc coating throws off zinc oxide fumes that can cause metal fume fever, an acute flu-like illness, so use local exhaust or a respirator.

Symptom	Likely cause	What to change
Pinholed bead	Damp rod, dirty gloves, dirty joint	Dry rods, clean gloves, grind clean
Gas pockets, rough root	Arc too long, wind on the puddle	Shorten arc, screen from drafts
Crack hours or days later	Hydrogen from damp rods or oils	Dry consumables, clean joint, preheat
Crack in root while welding	Restraint, overheating	Control heat input, smaller beads
Groove along the toe	Excess amps, long arc, travel angle	Drop amps, 10 to 15 degree angle
Slag under the bead	Wide weave, wrong angle, hard rapping	Stringer beads, correct angle, chip gently
Bead sits on the plate	Low amps, fast travel, mill scale	More heat, slower travel, grind clean
Black spatter, sooty bead	Too many amps, long arc, oil or wax	Trim amps, tighten arc, degrease

Look across the list and the pattern is clear. Almost every 7018 defect traces back to storage, cleanliness, or heat input, not the electrode itself. When the fix is not in the parameters, it may be in the filler metal, and if the joint is not plain carbon steel a different rod is the fix rather than a different technique. This guide to alloy steel welding electrodes breaks down the options.

Safety: Fumes, Ventilation, and the Real Hazards of Stick Welding

The most dangerous part of stick welding is the part you cannot see. Weld fume is a cloud of metal oxides drawn from three sources: the base metal, the filler metal in the rod, and the electrode coating. Arc heat vaporises those metals, and the hot particles cool in air into fine respirable dust that settles deep into your lungs. The arc also produces ozone and nitrogen oxides, leaving a poorly ventilated shop feeling like a head cold for days.

For carbon steel work like 7018, the headline hazard is hexavalent chromium. Chromium in the steel starts in a metallic state, and the arc converts it to the hexavalent form during the weld. Hobart Brothers’ technical bulletin on hexavalent chromium explains the chemistry, while OSHA’s welding factsheet covers the health effects. Cr(VI) fume is highly toxic: it burns and damages the eyes, skin, nose, throat and lungs, and it is a confirmed carcinogen.

The exposure limits employers work to

29 CFR 1910.1026 sets the legal thresholds for chromium (VI): a permissible exposure limit of 5 micrograms per cubic metre as an 8-hour time-weighted average, and an action level of 2.5 micrograms per cubic metre. Once exposure reaches the action level, the employer must run periodic air monitoring at least every six months, and every three months where exposure exceeds the PEL, plus medical surveillance and a written exposure control plan. For a shop owner welding 7018 all day in a closed corner, those numbers are the difference between a solvent-free shop and a documented exposure.

Ventilation: what OSHA actually requires

OSHA 1910.252(c)(2) requires general mechanical ventilation of at least 2,000 cubic feet per minute per welder in any of these situations:

• A space with less than 10,000 cubic feet per welder
• A room with a ceiling under 16 feet
• A confined space
• An area where partitions or other structures obstruct cross ventilation

That 2,000 cfm figure can be waived if you use local exhaust hoods or airline respirators instead. In larger spaces, natural ventilation qualifies only with 20,000 cubic feet per welder, a ceiling at least 16 feet high, and no cross drafts. Open the garage door and run a fan before you strike an arc.

Local exhaust hood placement

When you use a fume extraction hood instead of room ventilation, the distance from the arc decides how much airflow you need to capture the fume. OSHA’s table for a conventional hood assumes a control velocity of 100 linear feet per minute at the hood inlet:

Hood distance from arc	Airflow required	Minimum duct diameter
4 to 6 inches	150 cfm	3 inches
6 to 8 inches	275 cfm	3 inches
8 to 10 inches	425 cfm	4½ inches
10 to 12 inches	600 cfm	5½ inches

Move the hood closer and the required airflow drops sharply. A hood parked 12 inches away needs four times the air of one at 6 inches, which is why a well-placed small hood beats a big hood in the wrong spot.

Personal protective equipment

Your eyes come first. OSHA specifies a shade 10 lens for SMAW with 1/16 to 5/32 inch electrodes and shade 12 for 3/16 to 1/4 inch electrodes, worn in a proper welding helmet or hand shield. Add leather gloves, a leather jacket or sleeves, and flame-resistant clothing. If you need respiratory protection on top of ventilation, it has to sit inside a written 1910.134 respirator program with annual fit testing, not come off a hardware store shelf. Shop setups and equipment are covered in more detail in our airgas welding equipment guide.

Fire prevention and the label notice

Move combustibles at least 35 feet from the work site where practicable, and post a trained fire watch whenever anything flammable stays within 35 feet. The watch remains on site for at least half an hour after welding and cutting stop, because slag and sparks cool slowly and travel.

Filler metal containers must carry the label notice: “Do not use in areas without adequate ventilation. See ANSI Z49.1.” If the box in your truck is missing that notice, the product carries no manufacturer’s warning at all.

Galvanised steel, gouging, and confined spaces

Welding galvanised steel adds zinc oxide fume, which causes metal fume fever. Use local exhaust or a respirator, and grind the coating back well away from the joint. Carbon arc gouging, which you may use to clean up a 7018 root pass, produces far more fume than welding does and needs dedicated extraction, as covered in our air arc welding and carbon arc gouging safety guide. Higher-strength and alloy steels bring their own fume hazards, so review alloy steel welding electrode selection and safety before changing filler metal.

In a confined space, use an approved mechanical blower and rated exhaust. Never use oxygen for ventilation. Enriching the space with oxygen creates a fire and explosion risk and is one of the fastest ways to turn a weld into a catastrophe.

Safety checklist

• Ventilation running before the arc strikes: 2,000 cfm per welder, or a hood 4 to 6 inches from the arc
• Correct shade lens for the electrode diameter, inspected for cracks and pitting
• Leather gloves and sleeves, clean and dry, no synthetic materials
• Respirator use inside a written 1910.134 program with annual fit tests
• Combustibles moved 35 feet away, or a fire watch posted and kept for 30 minutes after the arc goes out
• Filler metal container carries the ANSI Z49.1 ventilation notice
• Galvanised or coated surfaces ground back, with extraction or respiratory protection in place
• Confined space permit, attendant outside, and no oxygen used for ventilation

Quick Reference: 7018 Specifications, Amps Table, and Buying Checklist

Everything in this guide comes down to a few numbers printed on the side of a box. Here they are gathered in one place, laid out so you can pull them up on a phone at the tailgate or print them for the shop wall. If you are new to stick welding, it also helps to understand why SMAW still wins on so many jobs.

E7018 Specification Sheet

Specification	E7018 (AWS A5.1)
Classification	E7018 under AWS A5.1 (also sold as E5018 under Chinese GB/T 5117)
Coating type	Iron powder low hydrogen
Tensile strength	70 ksi (about 480 MPa) minimum
Yield strength	58 ksi (about 400 MPa) minimum
Elongation	22 percent minimum
Welding positions	All except vertical down
Usable current	AC and DCEP
Penetration	Medium
Diffusible hydrogen	H4 (4 ml/100 g or less) or H8 (8 ml/100 g or less)
Impact requirement	Standard: 20 ft-lb at -20°F. “-1” suffix: 20 ft-lb at -50°F
Storage requirement	Hermetically sealed package or electrode oven

The positions line is the one people misread most often. E7018 is an all-position electrode, which is why it works well for the general all-position welding rod considerations on a tower, a pipe or a repair bracket, but it is explicitly not classified for vertical down. For higher-strength joints, our guide to alloy steel welding electrode selection and safety covers the matching classifications.

Amperage by Electrode Diameter

Electrode diameter	Operating amperage
3/32 inch	80 – 100 A
1/8 inch	90 – 150 A
5/32 inch	110 – 230 A
3/16 inch	150 – 300 A
7/32 inch	220 – 350 A
1/4 inch	270 – 380 A

These ranges follow the published operating parameters for 7018 electrodes published by Hobart Brothers. Treat them as a starting point rather than gospel: the data sheet for the specific product in your hand governs, and a written WPS for the job overrides any generic table, including this one.

Buying Checklist

• Read the classification line first. Confirm the box says E7018 or E7018-1. The “-1” suffix is the tougher impact rating, not a different rod.
• Decide if you need an AC-capable variant. If your only power source is a generator, pick a product marketed for AC such as Lincoln Electric’s Excalibur 7018 AC. Standard E7018 runs fine on AC, but the AC-optimised version holds a more stable arc.
• Match the hydrogen designation to the code. When the specification calls for controlled diffusible hydrogen, look for the H4 or H8 mark. H4 is the tighter of the two.
• Write down the batch or lot number. It is how the electrode is traced if a weld needs to be requalified later, and some job specifications require it on the paperwork.
• Buy the diameter you will actually burn. A 5/32 inch rod that fits the plate thickness beats a 1/4 inch rod you will overheat the joint to use. Buy a small box to trial, then restock in the size that works.
• Check the label notice. Filler metal containers are required to carry the warning: “Do not use in areas without adequate ventilation. See ANSI Z49.1 Safety in Welding, Cutting, and Allied Processes.” The OSHA 1910.252 ventilation standard is the reference behind it.

One more check before you order: confirm what the governing code actually requires. AWS D1.1, Structural Welding Code – Steel is among the most referenced welding codes in the world, and it, along with D1.5 for bridges, ASME Section IX, and the B31 piping codes, carries its own filler metal and qualification requirements. A shop that builds vessels or offshore structures should also review our guide to marine and offshore welding practices.

Final Verdict

So, what is 7018 welding rod used for? E7018 is a low-hydrogen, iron powder coated stick electrode for shielded metal arc welding of carbon and HSLA steel, and it is the correct default consumable for code-critical work in mild steel. It is specified for structural steel fabrication and erection, bridge work, boiler and pressure equipment, pipe fill and cap passes, shipbuilding and offshore structures, mining and heavy equipment repair, farm and ranch repair, and general shop maintenance wherever crack resistance and 70 ksi tensile strength matter. It runs on AC or DC electrode positive, deposits a medium penetration bead, and holds up in every position except vertical down.

The recurring theme of this whole guide is simple. The number on the box is not marketing, it is a metallurgical decision, and matching the rod to the joint matters as much as dialing in the machine. Get the classification right, keep the coating dry, feed it at the amperage the data sheet gives, and E7018 will quietly outlast the expectations you had for it.

Frequently Asked Questions

What is 7018 welding rod used for?

E7018 is a low-hydrogen, iron powder coated stick electrode used for welding carbon steel and HSLA steel in all positions except vertical down. Its typical jobs include structural steel fabrication and erection, bridges, boilers and pressure vessels, pipe fill and cap passes, heavy equipment and farm machinery repair, and general field maintenance. It is the standard choice wherever crack resistance and 70 ksi minimum tensile strength are required.

Can I weld stainless steel or aluminium with a 7018 rod?

No. E7018 is a carbon and low-alloy steel electrode, and using it on stainless or aluminium will produce an unsound weld and may release harmful fumes. Use an E308L or E309L type electrode for stainless steel and E4043 or E5356 for aluminium, or switch to TIG or MIG with the matching filler.

What does the number 7018 actually mean?

The ‘E’ means electrode, ’70’ means the as-welded deposit has a minimum tensile strength of 70,000 psi (about 480 MPa), ‘1’ means the electrode is approved for all welding positions, and ‘8’ means a low-hydrogen iron powder coating with medium penetration that runs on either AC or DC electrode positive. Added designators such as -1, H4, H8 and R specify impact toughness, diffusible hydrogen level and moisture resistance.

Do I really need to keep 7018 electrodes in a holding oven?

Yes, if you want to keep the low-hydrogen classification working for you. Low-hydrogen electrodes should be stored in hermetically sealed containers or electrode ovens, and the manufacturer’s storage and reconditioning instructions should be followed. An open box on a job site can absorb enough moisture to reintroduce the hydrogen cracking the classification is designed to prevent.

What polarity should I use for 7018, and can it run on AC?

E7018 works on both DC electrode positive and AC, but DCEP is preferred, especially at 5/32 inch and smaller, because it gives easier arc control and a cleaner bead. Some manufacturers sell AC-specific E7018AC variants whose coating additives hold a stable arc through the constant reversals of AC power, which is useful on generator-powered field welders.

What amperage should I set for a 3/32 inch 7018 electrode?

Hobart Brothers lists 80 to 100 amps for a 3/32 inch E7018. Other common sizes are 90–150 amps for 1/8 inch and 110–230 amps for 5/32 inch. Always follow the operating parameters printed on the manufacturer’s data sheet for the specific electrode, since they take priority over any generic chart.

Why does my 7018 weld come out porous?

The most likely causes are a damp electrode, dirty or sweaty gloves handling the rod, an arc that is too long, wind blowing the shielding column off the puddle, or oil, paint or mill scale on the joint. Fix storage first (sealed container or oven), then grind the joint clean within an inch of the weld, keep a tight arc, and shield the joint from drafts.

Can I use 7018 for the root pass on pipe?

Generally not for transmission pipeline root passes. Low-hydrogen stick electrodes do not match the penetration and root-pass performance of cellulosic rods, so cellulosic electrodes such as E6010 remain the standard root-pass consumable, with E7018 used for fill and cap passes where hydrogen control matters. Always confirm against the governing procedure and code.

Can I weld galvanised steel with 7018?

You can physically do it, but welding zinc-coated steel releases zinc oxide fumes that can cause metal fume fever, an acute flu-like illness. Use local exhaust ventilation or appropriate respiratory protection, grind the coating back from the joint, and consider an E6013, which is often preferred on galvanised steel because its coating adds little or no iron to the deposit.

Is E7018 the same thing as a 7018 rod?

Yes. ‘7018’ is simply the shorthand welders use for the electrode classified E7018; ‘rod’, ‘electrode’ and ‘stick’ are interchangeable in everyday shop talk. You will also see the same electrode classified as E5018 under the Chinese GB/T 5117 standard and sold as ‘7018-AC’ when it is optimised for AC welding.