Flux Core Welding Chart: The Complete Settings Guide

You finally get the wire loaded, the gun hooked up, and the helmet down — and the chart you pulled up on your phone says something completely different from what the machine does. That moment of staring at a pile of settings tables is where most flux core jobs go sideways. The truth nobody tells you at the counter is that there is no single universal flux core welding chart; there is a family of them, and picking the right one depends on four letters printed on the wire spool and which machine you are holding.

What a Flux Core Welding Chart Actually Tells You (And What It Doesn’t)

Three charts are open on your phone. One is for solid wire, one belongs to a self-shielded spool you do not own, the third is for a gas-shielded wire your machine barely runs. The plate is not going anywhere and somebody is waiting on the other end of the fit-up. That “no chart for exactly my wire” hesitation is where a lot of flux core work starts on guesswork instead of on data.

So let’s define the thing precisely. In practice, a flux core welding chart is a reference table that maps a wire classification and wire diameter to the machine settings needed to produce a stable, usable arc. A chart worth having on your phone gives you six things:

• Wire diameter and classification (the AWS designation off the spool label)
• Arc voltage
• Wire feed speed
• The amperage you should expect to land on
• Polarity
• For gas-shielded wire: the shielding gas type and flow rate

That is genuinely useful, and on its own it is still not enough to produce a repeatable weld. Here is the honest answer to the question most people search for: there is no single universal flux core welding chart. Self-shielded flux core (FCAW-S) and gas-shielded flux core (FCAW-G) are different processes that happen to share a name, and they get separate charts with separate numbers. Even inside one process, settings shift with wire diameter, material thickness and welding position. A chart for 0.045 inch E71T-11 on 1/4 inch plate in the flat position is not a chart for 1/16 inch E71T-8 on 16 gauge sheet in vertical up.

What the chart must specify	Self-shielded FCAW-S	Gas-shielded FCAW-G
Wire classification	E71T-11, E71T-8 (and other self-shielded grades)	E71T-1, E71T-5, E71T-GS and similar
Shielding gas	None. The flux core shields the arc itself	100% CO2 or an argon/CO2 blend, flow rate in cfh
Polarity	DCEN (straight polarity)	DCEN per the manufacturer’s data sheet
Slag and cleanup	Heavier slag, chipping required	Much less slag, cleaner bead
Typical amperage range	Wider spread, roughly 40 to 300 A	Narrower, machine and wire dependent

What the chart does not tell you matters just as much. A table cannot show you wire extension (stickout), drag angle, travel speed, bead placement, joint preparation, preheat, or how tight your fit-up is. Those technique variables account for a large share of weld quality, and no number in a spreadsheet compensates for a 3/16 inch gap that someone clamped closed with a pry bar.

One more distinction that matters legally as much as technically: a chart is a starting point for setup, not a governing document. For code-controlled work, the filler metal manufacturer’s data sheet and a qualified welding procedure govern. AWS standards such as D1.1 for structural steel and D1.8 for seismic provisions set the qualification and documentation requirements, and ASME B31.3 does the same for process piping. The chart gets you to the start of the gate; the data sheet and the procedure qualification get you through it. You can check the underlying standards in the AWS standards library.

This matters more than it sounds, because self-shielded flux core is popular precisely for speed. Hobart Brothers notes that structural contractors have converted from SMAW (stick) to self-shielded FCAW specifically to improve productivity and reduce labor cost. That gain evaporates if the first twenty minutes of every job are spent guessing at voltage. To see the process we are measuring against, read our guide to why SMAW still wins in certain situations.

Both workhorse self-shielded grades, AWS E71T-11 and AWS E71T-8, are described as versatile, all-position, general-purpose wires. All-position means the chart rows for vertical up and vertical down are not optional reading; they carry their own parameter relationships. Position-specific guidance for stick and flux core consumables is covered in our all-position welding rod guide.

Here is what this guide gives you. You will build a master chart you can tune from wire diameter, material thickness and position, learn how to decode the four letters and trailing digits printed on the spool so you pick the right chart in the first place, and pick up the technique variables a table cannot show. Then we walk through a symptom-by-symptom troubleshooting guide, because the fastest way to find your starting point is often to recognize the mistake you are already making.

The chart tells the machine what to do. Your hands, your wire extension and your fit-up tell the weld what to become. Keeping those two things in balance is the whole craft.

I’ll rewrite this section to fit the 560-840 word range while keeping the heading, facts, and all links.836 words, all four links preserved, same heading, all key facts retained.

How to Read a Flux Core Welding Chart: The Six Numbers That Matter

Every flux core settings chart looks the same: rows of numbers, voltage and wire feed columns, a gas column, a polarity footnote. Most never explain what those numbers do, and only one or two are actual settings. The rest are outcomes or technique habits.

1. Wire Diameter: A Choice, Not a Setting

Wire diameter is not a setting either. You pick the spool before you pick a number. Common self-shielded sizes are 0.030, 0.035, 0.045, 1/16 inch and 5/64 inch, and Hobart Brothers makes E71T-11 from 0.035 inch through 5/64 inch, so the smallest size on a chart may not exist for your wire.

Thicker wire carries more metal per inch of travel, so it deposits faster and lays in more heat. A 0.035 inch wire on thin sheet might run 70 to 90 amps, 0.045 inch wants more heat, and 5/64 inch needs a big machine. Fighting burn-through on 16 gauge? Often a thinner wire is the fix.

2. Voltage: Arc Length and Bead Shape

Voltage is a proxy for arc length. More voltage means a longer arc and a wider, flatter, more fluid puddle. Less voltage means a shorter arc and a narrower, more dug-in bead with better penetration.

Hobart gives 17 to 22 volts and 50 to 275 amps for AWS E71T-11 by diameter, and 18 to 23 volts and 200 to 275 amps all-position for AWS E71T-8. E71T-8 lives in a narrow voltage window at high amperage, while E71T-11’s wider range makes it the forgiving general-purpose wire most shops start with.

3. Wire Feed Speed: The Real Setting

The most misunderstood column. On a constant voltage machine, wire feed speed is the control and amperage is the outcome: you set a feed rate in inches per minute, the machine matches voltage to it, and amperage follows. The amps on your display are calculated, not a dial you set.

Hobart explicitly recommends constant voltage power sources for both E71T-8 and E71T-11 and warns that a constant current source fluctuates too much with these wires, causing porosity and inconsistent weld quality. On a CC machine the arc shows the bad guess through spatter, stubbing or a wandering bead. Amperage climbs roughly with feed speed, and heavier diameters push it higher.

4. Polarity: Often Set Wrong

Self-shielded flux core runs on DCEN, straight polarity (direct current electrode negative), and common gas-shielded flux core wires do too. Get it backwards and you get heavy spatter, an unstable arc and porous deposits, a common cause of “right settings, awful weld” complaints. Confirm the switch first; the Lincoln Electric overview of flux cored electrode usability designators maps classifications to process and position ratings.

5. Stickout: A Technique Number

Stickout is how far the wire extends past the contact tip, and it never appears on a chart because it is not a machine setting; you control it with the gun angle. E71T-11 wants about 1/2 to 3/4 inch of extension depending on diameter, with a 10 to 20 degree drag angle. E71T-8 runs longer, around 1 inch to 1-1/4 inch, because its heavier slag needs that wire to hold a steady arc. Larger diameter needs longer stickout. Too long raises resistance heating and spatter; too short and the wire stubs, the arc pops, the deposit looks inconsistent.

6. Gas Type and Flow Rate

If your spool says “G” (self-shielded), there is no cylinder and no flow rate. Anything else adds two columns: shielding gas type and flow rate in cubic feet per hour. Typical choices are 100 percent CO2 or a 75/25 argon/CO2 blend. Too little gas and you lose shielding, showing up as oxidation, porosity and a dirty-looking bead. Too much and nozzle turbulence disrupts the arc and adds spatter. The chart assumes a specific gas range at the nozzle, and MIG numbers do not transfer.

Putting the Chart to Work

Start at the midpoint of the recommended range for your thickness, weld a 3 inch coupon in the same thickness and position as the real job, then adjust in small steps, one variable at a time. Voltage up widens and flattens the bead, voltage down digs it in for deeper penetration; wire feed up raises amperage and heat, wire feed down reduces spatter and burn-through risk.

That amperage readout is calculated from your wire feed speed and wire diameter, not measured at the arc, so trust the bead, not the number. Aluminum MIG welding settings follow the same logic.

Once a set of numbers passes inspection, write them down. That one-page shop chart beats any factory table because it is calibrated to your machine, wire and judgment. For aluminum and other non-ferrous work the rules shift, so use a reference such as Aluminum flux core welding techniques.

Two Charts, Not One: Self-Shielded vs Gas-Shielded Flux Core

Here is the thing nobody tells you at the counter: “flux core” is not one process with one settings chart. It is two processes sharing a name, and most confusing charts online come from self-shielded numbers being run on a gas-shielded wire.

The split comes down to how the puddle is protected. In self-shielded flux core (FCAW-S), flux compounds in the wire core decompose as the wire melts, creating their own shielding atmosphere, so no cylinder is needed. In gas-shielded flux core (FCAW-G), an external gas does the protecting while the core handles deoxidation and slag formation. That difference changes voltage, wire feed speed, bead shape, cleanup, fume, and wind tolerance.

Self-Shielded Flux Core (FCAW-S)

Self-shielded wire is why flux core earned its reputation in the field and on structural steel. No cylinders to haul, no regulator to freeze up, no gas lines snagging on rebar. On a long pipeline run, it is the only sane answer.

Hobart Brothers specifies DCEN (direct current electrode negative), also called straight polarity, for both its E71T-8 and E71T-11 self-shielded wires. That is the opposite of what most wire filler metals use, and running it backwards is a fast way to get spatter and a porous, ugly bead. See Hobart’s technical overview of flux core wire for specifics.

The tradeoff is cleanup and fume. Self-shielded wire lays down substantially more slag, and T-8 wires are noted for very heavy slag that can interfere with the arc and keep the bead from wetting out. On vertical or overhead passes that slag can sit in the root and cause inclusions. The fume is heavier too, which is why NIOSH treats welding fumes as a serious respiratory hazard.

Gas-Shielded Flux Core (FCAW-G)

Gas-shielded flux core is the neat-looking sibling. Add a shielding gas and you get less slag, fewer fumes, lower spatter, and a bead that looks placed rather than dumped. It suits visible work, stainless, and jobs where appearance or code inspection will look at the profile.

The costs are real: cylinders, flow rate to manage, and a wire genuinely sensitive to wind. A breeze strips the shielding away and you get porosity. Confined spaces are harder too, with both fume and cylinder to manage.

The Gas-Shielded Settings Table

A gas-shielded flux core chart has two columns a self-shielded chart does not: shielding gas type and flow rate in cubic feet per hour (cfh). Neither is cosmetic. Gas type sets arc characteristics and bead shape; flow rate affects shielding coverage and arc stability. Too little flow gives oxidation and porosity, too much disrupts the arc, especially with heavier blends.

Manufacturer-verified examples for three common gas-shielded classifications:

Wire Classification	Shielding Gas	Flow Rate	Notes
AWS E91T5-B3M H8	70–80% argon / 20–25% CO2	35–50 cfh	Basic-type wire; see Hobart’s guide to flux cored wires for high-temperature and high-strength applications
AWS E111T-1-GM H4	75–80% argon / 20–25% CO2	Per manufacturer spec	Rutile-type gas-shielded wire
AWS E121TG-GC H4	100% CO2	Per manufacturer spec	Hobart specifies 100 percent CO2 for this wire

Notice the blends. The argon/CO2 mixtures are deliberately richer in argon than the classic 75/25 used for solid-wire MIG, because the flux core adds its own deoxidizing and slag-forming chemistry. Pure 100% CO2 is denser and penetrates deeper but runs a harsher, spatterier arc, and wires are rated for one gas or the other.

Why You Cannot Copy Your MIG Settings

Someone grabs a solid-wire MIG setting sheet, punches the same voltage and wire feed speed into a flux core gun, and wonders why the arc sounds like a gravel truck. It will not work: flux core wire is larger in diameter, runs at lower feed speeds, and operates in a different voltage window. Lincoln Electric’s page on flux cored electrode usability designators covers the classification side, but treat a gas-shielded chart as its own document, not a converted MIG chart.

Polarity is the other silent variable. Hobart specifies DC electrode negative for the gas-shielded wires above as well. Leave your machine on electrode positive and the wire behaves like it is running backward: unstable arc, spatter flying. Confirm polarity against the spool label before dialing in anything.

Which One Should You Be Running?

Choose self-shielded for work in the weather, on rusted or dirty steel, wherever a cylinder is a liability, or on long runs needing maximum deposition. Choose gas-shielded when appearance matters, for stainless or aluminum (see what actually works for aluminum flux core welding), when code requires clean profiles and low slag, or when fume control in an enclosed space decides the job.

Your MIG cylinders feed your gas-shielded gun too, so how your supplier mixes blends matters. The guide to AllGas welding supply, gases and services is a reasonable primer on the gas side.

Bottom line: two processes, two charts. The first question when you pull up a flux core welding chart is not “what diameter am I running” but “is this wire shielding itself, or is a cylinder doing it.”

Decoding the Wire Label: AWS Classifications and What the Digits Promise

Before you touch the amperage knob, read the spool. That label is the master key to every chart in this article. Two wires can look identical on the shelf, weigh the same, and cost about the same, yet demand different voltage, different shielding gas, and even different polarity. Only a string of letters and numbers tells them apart, and most people learn to ignore it.

The good news is that the system is logical. Once you decode the AWS classification and usability designators, you can walk into any shop, pick up any spool, and know in ten seconds which flux core welding chart to pull up.

Character by Character

Character	What it means
E	Electrode. This is the consumable classification prefix. AWS also uses an A prefix for arc welding electrode classifications, so the E is your signal that you are holding a consumable electrode wire.
7	Tensile strength group, in units of 10,000 psi. A 7 means the deposited weld metal is rated at a minimum of 70,000 psi tensile.
1	Material group. A 1 is carbon steel. Change the material and this digit changes, which is why aluminum flux core wire carries an entirely different number set (see aluminum flux core welding for that side of the family).
T	Tubular wire, meaning it has a core. Solid MIG wire uses an S instead, as in ER70S-6.
1 / 5 / 8	Slag type and shielding method. A 1 is rutile, a 5 is basic, an 8 is a self-shielded classification with toughness requirements.
Trailing digits	The usability designator, such as the 11 in E71T-11. It identifies a specific self-shielded classification and its position and slag characteristics.

So E71T-11 reads, in plain English: a tubular electrode for carbon steel, minimum 70,000 psi tensile, rutile-classified right after the T, self-shielded in the final digits. Every one of those facts lands you on a different row of a chart.

The Two Self-Shielded Workhorses

Most shops own exactly two self-shielded wires, and confusing them is the most common label-related mistake in the field.

E71T-11 is the forgiving one. It has a wide operating window, and Hobart Brothers notes that AWS D1.1 permits E71T-11 wire for welding material less than 1/2 inch thick. The same source is blunt about the limitation: T-11 wires carry no toughness properties and therefore are not used for critical welding. That is not a defect. It is the trade for a wire that lays down beautifully, tolerates sloppy fit-up, and rarely surprises you at the torch.

E71T-8 is what you reach for when the job matters more than the schedule. It must meet a toughness requirement of 20 foot-pounds at -20 degrees Fahrenheit. Add the J designator, as in E71T-8J, and the requirement tightens to 20 foot-pounds at -40 degrees Fahrenheit. Because of that toughness behavior, E71T-8 wires are often approved for Demand Critical welds under the AWS D1.8/D1.8M Structural Welding Code, Seismic Supplement.

The Gas-Shielded Family

E71T-1 is the rutile gas-shielded wire and the most forgiving member of that family. Its operating window is wide, the bead is easy to control, and it is a sensible default when you move from self-shielded work to a shop with a gas tree. Some classifications add a C suffix, such as E71T-1C, to indicate the wire is approved for 100% CO2 shielding rather than an argon blend.

E71T-5 is the basic wire. Basic slag gives you a weld that is deeper, tougher, and more crack resistant, which is exactly why E71T-5 is a staple for pressure applications governed by ASME B31.3 process piping and why chrome-moly work leans on basic wires. Hobart’s technical guidance on flux-cored wires for high-temperature and high-strength applications covers that family in detail. If you are running alloy or chrome-moly filler, this is also the point to revisit alloy steel welding electrode selection and safety, since the matching rules are stricter than for plain carbon steel.

And Then There Is the Label That Is Not Standard

Walk into any supply counter and you will eventually see E71T-GS on a spool. Be aware: GS is a manufacturer-added designation, not part of the formal AWS classification. It typically signals a general-purpose, single-pass wire. The classification tells you how it is classified; GS tells you how the mill wanted you to use it. Treat it as a hint, not a specification, and always confirm the real AWS numbers on the spool before you trust a chart with them.

One practical habit pays off forever: write the full classification and diameter on your shop chart. Spools get swapped, half-empty spools get lost, and an E71T-11 spool sitting next to an E71T-8 will wreck a schedule if you assume right. If the wire is gas-shielded, note the cylinder and blend too, and get the gas right up front with a solid guide to welding gases and cylinder supply before you dial in the flow rate.

The Master Flux Core Welding Chart: Diameter, Thickness and Position

This is the table most people come here for. Below it is a single starting-point chart built from the published operating windows of common flux core wires and the physical relationship between wire feed speed, wire diameter and amperage. It covers self-shielded and gas-shielded wire, from 18 gauge sheet metal to half-inch plate and beyond.

Read it as a map, not a law. It is a tuning starting point, not a substitute for the manufacturer’s data sheet, and on code-governed work the qualified welding procedure and the applicable code always win. Burn in on a short coupon before you commit to a production job.

Self-Shielded FCAW-S: E71T-11 and E71T-8 Starting Points

E71T-11 self-shielded wire runs across a verified operating window of 17 to 22 volts and 50 to 275 amps. E71T-8 spans 18 to 23 volts and 200 to 275 amps for all-position work. E71T-11 is commonly offered from 0.035 inch through 5/64 inch diameter, and larger diameters deposit faster. Hobart Brothers notes that the smallest commonly available E71T-8 diameter is 1/16 inch, because the higher fill percentage in that wire makes drawing it down to smaller sizes difficult.

Wire & Dia.	Material	Voltage	Wire Feed Speed (ipm)	Est. Amps
E71T-11 .030	18 ga (0.047″)	17.5 V	180	45–55
E71T-11 .030	16 ga (0.062″)	18 V	260	65–75
E71T-11 .030	1/8″ plate	19 V	350	95–105
E71T-11 .035	18 ga (0.047″)	17.5 V	200	50–60
E71T-11 .035	16 ga (0.062″)	18 V	275	70–80
E71T-11 .035	1/8″ plate	19 V	350	105–115
E71T-11 .035	3/16″ plate	19.5–20 V	400	125–135
E71T-11 .045	1/8″ plate	19 V	300	125–135
E71T-11 .045	3/16″ plate	20 V	375	160–170
E71T-11 .045	1/4″ plate	20–21 V	450	185–195
E71T-11 1/16″	1/4″ plate	20 V	350	185–195
E71T-11 1/16″	3/8″ plate	21–22 V	450	235–245
E71T-11 1/16″	1/2″ plate	22 V	500	270–275
E71T-11 5/64″	3/8″ plate	21 V	400	245–255
E71T-11 5/64″	1/2″ plate	22 V	500	275 (max)
E71T-8 1/16″	1/4″ plate	18–19 V	350	200
E71T-8 1/16″	3/8″ plate	19–20 V	450	230–240
E71T-8 1/16″	1/2″ plate	20–21 V	500	255–275

Gas-Shielded FCAW-G Starting Points

Gas-shielded flux core trades slag for a shielding gas, and it runs at higher amperage for the same wire feed speed than most solid wire MIG settings. The E71T-1 rutile family typically runs on a 75/25 argon/CO2 blend. Pure CO2 needs roughly one to two volts more than a blend for the same wire and feed speed.

Wire & Dia.	Material	Voltage	WFS (ipm)	Est. Amps	Gas	Flow (cfh)
E71T-1 .035	18 ga (0.047″)	16–17 V	200	70–80	75/25 Ar–CO2	25–30
E71T-1 .035	1/8″ plate	17–18 V	275	95–105	75/25 Ar–CO2	30–40
E71T-1 .045	3/16″ plate	19 V	300	150–160	75/25 Ar–CO2	30–40
E71T-1 .045	1/4″ plate	19–20 V	375	180–190	75/25 Ar–CO2	30–40
E71T-1 1/16″	1/4″ plate	20 V	350	200–210	75/25 Ar–CO2	35–50
E71T-1 1/16″	3/8″ plate	21 V	425	235–245	75/25 Ar–CO2	35–50
E71T-1 1/16″	1/2″ plate	22 V	500	270–280	75/25 Ar–CO2	35–50
E71T-1 5/64″	1/2″ plate	22 V	500	275–300	75/25 Ar–CO2	35–50
E121TG-GC 1/16″	3/8″ plate	22–23 V	425	240–250	100% CO2	35–50
E121TG-GC 1/16″	1/2″ plate	23 V	500	270–280	100% CO2	35–50

Gas-shielded wires are classified for usability by the letter and digit pair on the spool, which is worth checking before you pick a row above. Manufacturer operating ranges for these wires are available in the Hobart Brothers flux core technical reference.

How to Read the Chart

• Find your thickness in the second column, then read across for voltage, feed speed and expected amperage.
• Flat and horizontal: use the numbers as printed. Horizontal fillets need a slightly slower travel speed than flat welds.
• Vertical up: reduce wire feed speed by 10 to 15 percent, drop voltage about half a volt to a volt, and slow your travel. Many shops choose a rutile gas-shielded wire for vertical work because self-shielded flux core is less forgiving here. See our all-position welding rod guide for how position changes filler metal behavior.
• Vertical down: keep the feed speed, drop the voltage slightly, and travel faster. Less total heat, so thin material is far less likely to burn through.
• Thick plate: run stringer passes at the lower end of the amperage range rather than one hot pass.

Finally, remember that heat input, not amperage alone, controls quality on thick plate. On half-inch and heavier material, control interpass temperature and use the filler metal classification your code calls for. AWS D1.1/D1.1M is the structural welding code covering building and bridge steel and it references filler metal classifications for exactly this reason.

The Variables a Chart Cannot Show: Stickout, Drag Angle, Travel Speed and Joint Prep

A settings chart answers two questions: what voltage and what wire feed speed. It cannot tell you how far the nozzle sits from the puddle, how fast you walk the gun, where you lay the bead, or how tight the plates sit against each other. Those are technique variables, and they are the difference between a chart that works on the bench and one that fails in the field.

Wire Extension (Stickout)

Stickout is the length of wire sticking out past the contact tip. It is the most overlooked number in flux core welding because it is not a machine setting. You set it with your arm.

Hobart Brothers specifies roughly 1/2 to 3/4 inch of stickout for E71T-11 wire, depending on diameter, paired with a 10 to 20 degree drag angle. For E71T-8 wire the recommendation goes longer, 1 inch to 1-1/4 inch, again scaling with diameter. Simple rule: bigger wire means longer stickout.

The reason is slag. E71T-8 produces heavy slag and forgives technique error less than the freer-flowing E71T-11, so it needs the longer extension to keep the arc stable and the puddle wetting out properly. A short stickout on E71T-8 causes stubbing and an erratic, popping arc.

Drag Angle and Travel Speed

The drag angle is the tilt you hold the gun away from the direction of travel, typically 10 to 20 degrees. Dragging the wire directs the arc into the leading edge of the puddle, which improves penetration and helps limit slag inclusions. Pushing works too, but it changes bead profile and heat distribution, so pick one habit and keep it.

Travel speed is where most self-shielded work goes wrong. Too fast and the bead thins, the toes undercut, and the slag drags behind the puddle instead of being lifted by the arc. Too slow and you pile heat into the joint, which is how burnthrough happens on thin plate.

Watch the ends of the bead. Slowing down at the toes to tie the weld in keeps the start and stop from leaving a cold, underfilled crater. With self-shielded wire this matters more, because the slag has to be broken and lifted at exactly the right moment, and a wandering puddle makes that harder.

Stringers Versus Weave Beads

Factor	Stringer	Weave
Travel path	Straight, no lateral movement	Side to side oscillation
Heat input	Lower, easier to control	Higher per inch, more burnthrough risk
Best fit	Thin to medium material, all positions	Heavy plate, flat and horizontal fill
Flux core fit	Preferred, easier slag control	Possible but slow, slag-prone

For flux core, stringers are the safer default. Weaving spreads the heat, and spreading heat is exactly what you do not want on 1/8 inch plate or in a vertical-up joint. A quick reference on how bead placement affects the whole joint is worth having next to the machine.

Vertical Up Versus Vertical Down

Position changes how voltage and wire feed speed relate, and the chart only gives you the flat and horizontal baseline. Vertical up needs lower wire feed speed, slightly lower voltage and slower travel so the puddle does not run ahead of you. The trade-off is higher heat input and burnthrough risk on thin material, so many shops save it for gaps and repair work.

Vertical down is faster and cooler. You can push a higher deposition rate, travel quicker and lay the bead with less chance of sag or undercut, which is why most structural work and clean, visible fillets run vertical down or horizontal.

Joint Preparation, Preheat and Fit-Up

Before the gun comes out, the condition of the joint decides how much heat you need. Mill scale, rust, paint and oil all have to come off the joint surfaces; a chart cannot make dirty steel weld. Clean with a wire wheel or grinder and treat the joint like a finished part of the assembly.

Fit-up matters just as much. An inconsistent root gap is the classic cause of burnthrough on one side and lack of fusion on the other. Tack the joint, keep the gap consistent, and remember that a wider gap needs more heat and sometimes a different bead placement strategy to fill.

Preheat and interpass temperature come from the procedure, not the chart. For code work they are specified in the applicable standard, such as AWS standards for structural fabrication or ASME B31.3 for process piping. Interpass limits protect the heat affected zone, and on alloy or chrome-moly materials preheat discipline is a discipline of its own.

The chart gets you to a starting arc. Stickout, drag angle, travel speed, bead placement and joint preparation turn that arc into a weld you would be willing to sign off on.

Troubleshooting the Chart: What Bad Welds Say About Your Settings

A flux core welding chart is only a hypothesis until the metal says otherwise. The bead reports first: spatter off the puddle, a stubbing arc that sounds like a pop gun, a seam that smells like wet cardboard. That feedback is what separates tuning from guessing.

Most flux core defects are not mysterious. They map back to a short list of settings, and the fix is usually small: a quarter-turn of voltage, a drier spool, a cylinder finally hooked up.

The Symptom-to-Cause Reference Table

Read the “Likely cause” column before you touch a knob. Most operators turn voltage first because it is the easiest one to reach.

Symptom	Likely cause	Corrective action
Excessive spatter	Voltage too high for the wire; incorrect polarity; stickout too long	Reduce voltage in small steps; confirm DCEN polarity on self-shielded wire; pull the contact tip back
Stubbing, popping arc	Wire feed speed too high for the voltage set; contact tip too close to work; worn or undersized tip	Match feed speed to voltage per the chart; hold proper nozzle-to-work distance; replace the tip first
Porosity (pits, open areas)	Wrong polarity on self-shielded wire; moisture pickup; gas-shielded wire with no gas; dirty or low-flow gas; wind	Verify polarity; open a fresh spool and keep it dry; confirm gas flow at the gun; shield from drafts
Worm tracking (dark trails under slag)	Moisture in self-shielded wire stored improperly	Store wire in its original packaging, dry and enclosed; replace the compromised spool
Slag inclusions	Poor drag technique; insufficient stickout; weaving too fast	Hold a 10 to 20 degree drag angle; restore proper wire extension; slow the weave or use a stringer bead
Undercut	Travel speed too fast; wrong work angle; insufficient voltage; poor technique	Slow travel, weave slightly into the sidewall, aim the torch squarely at the joint and into the toe
Overlap, excessive reinforcement	Voltage too low; travel speed too slow; wire feed too slow for the voltage	Raise voltage or feed speed to keep the puddle fluid; speed up travel to lay reinforcement down
Burn-through on thin material	Too much heat input; wire feed too fast; wrong joint design	Drop voltage and feed speed, add travel speed, use smaller wire, consider a backing bar or a fillet instead of a full-penetration butt
Flat, wide bead with poor penetration	Voltage too high; travel speed too fast	Lower voltage to narrow and focus the bead; slow travel so the puddle fuses the base metal

Notes on the Worst Offenders

Spatter on self-shielded wire is not cosmetic. Hobart Brothers notes that spatter burns are a leading cause of injury to welders working with self-shielded wire and hot slag. Wrong polarity produces poor welding performance and increased spatter. If spatter appears on a spool that always behaved, check the polarity switch first.

Porosity and worm tracking are usually storage problems, not machine problems. Hobart Brothers states that moisture in self-shielded flux cored wire can lead to worm tracking, a discontinuity similar to porosity that forms under the slag. Keep wire in its original packaging, dry and enclosed.

Stubbing is counter-intuitive. When wire feed speed outruns the voltage, the arc shorts out, you hear a pop, the machine recovers, and the cycle repeats. Adding voltage usually fixes it; adding feed speed makes it worse. A worn contact tip causes the same symptom, so replace it first.

The Three-Step Diagnostic Before You Blame the Machine

When a job starts producing bad welds mid-project, resist swapping the spool or calling the technician. Run these three checks in order; they rule out most problems in minutes.

1. Check polarity. Confirm DCEN (straight polarity, electrode negative) for self-shielded flux core. Reversed polarity changes arc character, spatter rate and penetration, and it is the most common “settings” error that is really a switch position.
2. Check wire and gas condition. Check the spool date code and storage, confirm the wire feeds freely from the drive roll, and for gas-shielded wire verify gas is flowing at the gun with the cylinder open. A windy bay will destroy shielding regardless of the flow meter.
3. Re-tune voltage and wire feed first. Return to the chart midpoint for your diameter and thickness, make a fresh coupon, and adjust from a known baseline instead of nudging two variables at once.

And when the weld comes out clean, write the numbers down. A one-page shop chart with wire, diameter, thickness, position, voltage, feed speed and gas settings beats any manufacturer’s table because it reflects your machine and your hands.

For context on where to spend troubleshooting time, see our look at advantages of stick welding and the broader flux cored wire selection guidance. If the material is aluminum rather than steel, the settings logic changes: aluminum flux core welding covers that separately.

Finally, a chart cannot save a bad joint. Confirm fit-up, joint preparation and surface condition are within spec. Most “settings problems” on thin or rusty material are really preparation problems, and no voltage setting fixes a gap that keeps opening.

Flux Core vs MIG vs Stick: Choosing the Right Process (and Chart)

Every process has its own settings chart, and using the wrong one is an expensive mistake. A solid wire chart puts you in a voltage range too low for flux core, and a stick chart has no voltage column. Stick (SMAW) is the workhorse, MIG (GMAW) the clean generalist, and flux core (FCAW) the productivity play. Hobart Brothers notes that structural contractors moved largely from stick to self-shielded FCAW to raise productivity and cut cost, because self-shielded flux core is simply faster.

Self-Shielded FCAW (FCAW-S): The Productivity Choice

Self-shielded flux core wire carries its own shielding agent in the core, so there is no gas cylinder, no regulator, and no hose to snake around a job site. It welds outdoors in wind and cold where a gas-shielded gun would lose protection, and it handles dirty, rusted, or mill-scale-covered steel that a solid wire gun would sputter on. Modern wires are also easier to use and produce better weld quality than earlier generations.

E71T-11 wires are easy to use and forgiving of technique errors, a common training choice for newer operators. Hobart notes that suitcase-style wire feeders are commonly paired with self-shielded wires for portability. The trade-off is cleanup: heavy slag, more fume, and a bead that needs grinding or chipping.

Gas-Shielded FCAW (FCAW-G): The Clean, Code-Friendly Choice

Add an external shielding gas, usually 100% CO2 or a 75/25 argon/CO2 blend, and you get a cleaner deposit with less slag and lower spatter. That matters for visible work, stainless overlays, and code-governed joints. Gas-shielded basic-slag wires such as E81T5-B2M H8 and E91T5-B3M H8 weld readily out of position, including vertical up and vertical down. The cost is portability and weather: you depend on a gas supply, and wind disturbs the shielding just as it disturbs TIG. For code work, filler metal selection carries obligations under standards such as ASME B31.3 process piping and the AWS welding standards, and a qualified procedure still governs.

MIG (GMAW): Cleanest and Most Versatile

Solid wire MIG is what most shops reach for first: simple, clean, fast to set up. There is no slag, the bead looks good as-laid, and the chart is simple to learn: lower voltage range, higher wire feed speed, gas always part of the equation. MIG handles thin material beautifully and is the standard for aluminum work, covered in our aluminum MIG welding guide. It loses ground on thicker structural steel and less-than-clean metal, where solid wire spatters more as amperage climbs and is not forgiving of rust, paint, or scale. When a fabricator says flux core is easier to weld, they mean dirty, thick, outdoor steel.

Stick (SMAW): Lowest Cost, Widest Access

Stick wins on equipment cost and freedom. There is no wire feed mechanism and no gas, the electrode holder weighs almost nothing, and you can weld in any position, including overhead, without repositioning a machine. It works in places a wire feed cannot reach, as our breakdown of the advantages of stick welding explains. The costs are arc time and consistency: more time striking arcs and cleaning rods, with a lower deposition rate per electrode. On a long production weld the difference in hours is dramatic, which is why the industry moved toward flux core.

Side-by-Side Comparison

Axis	FCAW-S (Self-Shielded)	FCAW-G (Gas-Shielded)	GMAW (MIG)	SMAW (Stick)
Shielding gas	None	Required	Required	None
Slag	Heavy, needs chipping	Light	None	Moderate
Deposition rate	Highest	High	Moderate	Low
Best fit	Structural steel, field work, dirty surfaces	Coded and visible work, clean profile	Thin material, non-ferrous, general fabrication	Repair, field access, minimal equipment
Positions	All, strong flat and horizontal	All, vertical up and down on basic wires	Flat, horizontal, vertical	All, best overhead access

Why the Chart Changes With the Process

• Stick has no voltage and no wire feed. A stick chart lists amperage, electrode type, and polarity only, with arc length set by travel speed and standoff.
• MIG runs lower voltage and higher feed speed. Solid wire deposits with a short arc, so charts show roughly 17 to 24 volts, feed speeds climbing as amperage rises, and gas mix and flow rate on every row.
• Flux core sits in the middle, widest window on self-shielded wire. Self-shielded charts run roughly 17 to 23 volts with feed speeds across a broad range, and machine amperage follows the feed rate.

How to Choose in Practice

Ask three questions: is the job structural, pressure-retaining, or appearance-critical? Is the work outdoors or on unground steel? How many hours of arc time are on the table? The process usually picks itself. A bridge job on rusted plate in a cold field with no gas truck on site: self-shielded FCAW. A stainless tank with a visible finish and a procedure that must hold pressure: gas-shielded FCAW or TIG, depending on wall thickness.

If a job mixes aluminum with steel, the charts are not interchangeable; our guide to aluminum flux core welding covers what works there. Nonferrous work belongs in the TIG and MIG column.

A settings chart only means something once you know which process it belongs to. Choose the process for the joint, the conditions, and the hours, then pick the matching chart. Using the wrong chart is not a small adjustment, it is a different welding process pretending to be the one you know.

Safety, Fume Control and Code Requirements for Flux Core Work

A clean, well-shaped bead is worthless if it costs you a trip to the emergency room. Flux core has a safety profile that differs from MIG in ways the settings chart never tells you. Self-shielded wire generates more fume and far more slag, and gas-shielded wire adds a cylinder to manage. Both deserve a deliberate safety plan.

Welding fume is a mixture, not a single substance

What comes off the arc is not one chemical but a shifting cocktail of metal oxides and fluorides, and the exact composition changes with the base alloy, the process and the consumable. That is why regulators approach it in layers.

The NIOSH Pocket Guide to Chemical Hazards lists welding fumes with an OSHA permissible exposure limit of none. There is no single blanket limit to lean on; instead you must meet the component-specific limits in OSHA Appendix G and NIOSH Appendix A, so your exposure assessment depends on what you are actually welding, not on a generic “welding fume” number.

NIOSH describes metal fume fever with flu-like symptoms including dyspnea, cough, muscle pain, fever and chills, and notes the risk of interstitial pneumonitis in severe or repeated exposures. The tell-tale pattern is a welder who feels fine at lunch and achy, feverish and short of breath by end of shift, symptoms that clear overnight only to return the next day. NIOSH also lists welding fumes as a potential occupational carcinogen with the lung as the cancer site. NIOSH methods 7300, 7301 and 7303 describe how fume samples are collected and analyzed.

Hexavalent chromium: the limit that catches people

Hexavalent chromium is a component of stainless steel and many nonferrous alloys, and OSHA regulates it under a dedicated standard rather than folding it into general welding fume. The numbers make compliance demanding:

Contaminant	OSHA PEL	NIOSH REL	Why it matters
Welding fumes	None listed	Component-based	Check each component limit
Hexavalent chromium	5 µg/m³	0.2 µg/m³	Stainless/nonferrous work; NIOSH is 25× stricter
Carbon monoxide	50 ppm (8-hr TWA)	35 ppm TWA, 200 ppm ceiling	Arc-generated; worse in enclosed spaces

The OSHA hexavalent chromium exposure controls page spells out the requirements: exposure assessment, regulated areas, respiratory protection and hygiene practices. Filler metal choice matters too, which is why shops pay attention to what is in the wire, not just in the plate. Our guide to alloy steel welding electrodes, selection, use and safety covers how filler chemistry shapes the fume profile.

Carbon monoxide and the self-shielded advantage

OSHA’s welding fact sheet states plainly that carbon monoxide gas can form during welding and poses a serious asphyxiation hazard. That is the hazard people associate with gas-shielded wire in a confined space, and the reason many shops choose self-shielded flux core for tank interiors, field repairs and indoor work where a cylinder is unwelcome.

Shielding gas cylinders still need respect. Keep them upright, chained or restrained against tipping, capped when not in use, and away from heat, sparks and traffic. Never roll or drag a cylinder. More on cylinder handling in AllGas welding supply, gases, services and safety guide.

Controls that actually work

• Local exhaust ventilation. A portable LEV hood or arm source close to the work captures fume before it reaches your breathing zone. General ventilation dilutes; LEV captures.
• Respiratory protection. Required use must be part of a written program with medical clearance and fit testing. A disposable dust mask is not a substitute for a welding fume cartridge or a supplied-air respirator.
• Eyes, face and skin. A proper shade lens plus a face shield for chipping, leather or heat-resistant gloves, sleeves and a jacket. Flux core spatter is hot and it sticks to skin and burns.
• Spatter and hot slag. Self-shielded slag comes off the bead hot and can pop. Wear eye protection during chipping and never look into slag that has not cooled. Massachusetts safe welding practices guidance is a good practical reference.
• Fire watch. Slag and spatter travel farther than people expect. Keep combustibles clear, watch for smoldering in adjacent bays and cavities, and keep the watch until the area is confirmed cool.

Codes and qualification close the loop

Safety and code compliance meet in one place: the written procedure. A chart gives you numbers to start, but code work requires a qualified procedure and a qualified welder.

• AWS D1.1 governs structural steel welding, including the AWS welding standards family and its associated qualification requirements.
• AWS D1.8/D1.8M is the Structural Welding Code, Seismic Supplement, which governs Demand Critical welds and imposes tighter qualification and inspection expectations than ordinary structural work.
• ASME B31.3 covers process piping fabrication, assembly, erection, inspection and testing.

Performance qualification, continuity and the documented WPS/PQR are what make a weld acceptable. A shop chart helps you get there quickly; it does not substitute for any of it. For more on how shop standards and safety practice intersect, see AJ Marine welding, processes, standards, safety and best practices.

Build Your Own Shop Chart: A Repeatable Setup Routine That Works

Every shop ends up with a scrap of paper taped above its wire shelf. It’s not fancy, but it’s what keeps settings consistent from one welder to the next. A factory chart will get you close, but your own flux core welding chart will get you the same good bead, every time. All it takes is one morning of testing.

Step 1: Read the Spool

Before anything else, fill out your sheet straight from the spool label. Take note of the AWS classification, diameter, shielding type, and gas if it’s gas-shielded. If that label is unreadable, grab a new spool. More mismatched setups come from the wrong wire than any other mistake.

Step 2: Set Polarity and Confirm Your Machine

Flux core requires a constant-voltage (CV) power source. On CV, wire feed speed is your adjustment and amperage is calculated by the machine. If your machine is strictly constant-current (CC), it’s not the right fit for most flux core wires. For the vast majority of self-shielded and many gas-shielded flux core wires, set your machine to DCEN (straight polarity, electrode negative). Always reference your machine’s diagram for lead placement before flipping anything.

Step 3: Gas, Flow, and Environment

Only for gas-shielded wire. Secure the cylinder, crack the valve, and set your regulator to your starting flow rate. Don’t trust the gauge alone, use a flow meter to verify it. Too little flow causes porosity, while too much creates turbulence and wastes gas. Be aware of wind as well, as a breeze can strip shielding regardless of your settings.

Step 4: Load Wire and Drive Rolls

Confirm feed direction by running the gun dry with the tip off of the work. Adjust your drive roll pressure to the machine manual, just tight enough to feed without deforming the wire. From there, run wire out to a consistent length, as even small changes in stickout will affect resistance heating.

Step 5: Dial Stickout

Stickout is the wire past the contact tip. For E71T-11, aim for 1/2 to 3/4 inch. For E71T-8, aim for 1 inch to 1-1/4 inch due to its heavier slag. As a general rule, larger diameter wire calls for longer stickout. Keep your contact tip-to-work distance between 1/4 to 1/2 inch, ensuring it won’t touch on smaller wires.

Step 6: Set Starting Numbers and Adjust

Using the master chart from earlier in this article, set your voltage and wire feed speed for your wire diameter and material thickness, then note the resulting amperage. On many machines, this amperage is calculated, so don’t chase a displayed amp number. Make changes one at a time in small steps.

Step 7: Test on a Coupon

Weld a 3 to 4 inch coupon on the same thickness and in the same position as your job. Inspect the bead profile, slag release, spatter, arc sound, and if needed, a cross section for penetration. Heavy spatter or a stubbing, popping arc are both signs to adjust before moving to your workpiece.

Step 8: Record and Maintain Your Chart

For every successful setup, log the wire, diameter, thickness, position, volts, wire feed speed, resulting amps, gas and flow, stickout, and the date. Use the table below as your template to fill in your own proven numbers.

Wire	Dia.	Thk.	Position	Volts	WFS (in/min)	Amps	Gas	Flow (cfh)	Stickout	Date
E71T-11	0.035	1/4 in	Flat				None
E71T-11	0.035	1/4 in	Vertical				None
E71T-8	0.045	1/2 in	Flat				None
E71T-1-G	0.035	1/4 in	Flat

Print copies for the machine and truck. When it comes to repairs, the stick welding advantages article can be a solid fallback, but for flux core, this chart is your go-to tool.

Prep, Storage, and Compliance

No setting can compensate for poor prep. Grind mill scale and rust back to bright metal, control your fit-up and gap, and on multi-pass welds, chip or grind slag between passes. For self-shielded wire, Hobart Brothers specifically calls out drag technique with appropriate travel speeds to tie in the weld at the toes for clean results.

Finally, remember that your chart is not a qualification. As Hobart Brothers states, welding operator training and proper certification are essential to meet applicable codes. For structural work, this can include AWS D1.1/D1.1M:2025-AMD1, AWS D1.8 for seismic applications, and ASME B31.3 for process piping. A good coupon means nothing without a qualified procedure behind it.

Any time anything changes, from a new spool, to a worn contact tip, to a different machine, run one coupon and update your row. Treat it as a living document. One morning of notes will save you countless frustrating afternoons, and that’s the entire point of building your own shop chart.

Frequently Asked Questions

What polarity should I use for flux core welding?

Use DCEN (direct current electrode negative, also called straight polarity) for self-shielded flux core wire. Hobart Brothers specifies this for both E71T-8 and E71T-11 wires and notes it is the opposite of most other wire filler metals. Running the wrong polarity raises spatter and degrades weld quality, so double-check the machine setting before you start.

Do I need shielding gas for flux core wire?

It depends on the wire. Self-shielded wires such as E71T-11 and E71T-8 generate their own shielding from the flux core and need no gas cylinder, which is why they dominate field and site work. Gas-shielded wires such as E71T-1 need an external mixture — typically 100% CO2 or roughly 75/25 argon/CO2 — and welding without gas will produce a porous, oxidized bead.

What voltage and wire feed speed should I use for 1/4 inch steel with .035 flux core wire?

For self-shielded .035-inch wire on 1/4-inch carbon steel, start around 19–21 volts with a wire feed speed that lands you in the 150–200 amp range, then fine-tune from a test coupon. Hobart Brothers gives a 17–22 volt and 50–275 amp working window for E71T-11 across diameters, so that range brackets your starting point. Always confirm against the spool’s data sheet.

What is the difference between E71T-11 and E71T-8 flux core wire?

E71T-11 is the forgiving, general-purpose choice: a wide parameter window, no toughness requirement, and AWS D1.1 allows it for material under 1/2 inch thick, so it suits tacks and light stitch welds. E71T-8 must meet a 20 ft-lb toughness requirement at -20°F (E71T-8J at -40°F), has no thickness restriction, and is used on critical and seismic work — but it is less forgiving and produces heavy slag.

Can I run flux core wire in a standard MIG welder?

Usually yes. Nearly all modern MIG machines can run self-shielded flux core if they are constant-voltage (CV) capable, which most are. Hobart Brothers warns against running E71T-8 or E71T-11 on a constant current power source because voltage fluctuation causes porosity and inconsistent welds. You also need to fit a spool gun or wire feeder and the correct drive rolls and contact tip.

Why am I getting porosity and worm tracking in my flux core welds?

Worm tracking is a slag-covered discontinuity that Hobart Brothers links directly to moisture pickup in self-shielded wire, so store spools sealed and dry between 40 and 120°F with humidity under 80%. Porosity more often traces to wrong polarity, running gas-shielded wire without gas, dirty or leaking gas lines, or wind blowing the shielding away.

How thick of material can I weld with .035 flux core wire?

With .035-inch self-shielded wire you can realistically cover roughly 16 gauge up to 1/2-inch plate with good control, and push heavier with a 5/64-inch wire and proper preheat. If you need to weld thicker material regularly, step up to 0.045, 1/16, or 5/64-inch wire rather than trying to push .035 past its comfortable range.

How long should the stickout be for flux core welding?

Hobart Brothers recommends about 1/2 to 3/4 inch for E71T-11 and 1 to 1-1/4 inch for E71T-8, with larger wire diameters needing a longer extension. Too short causes stubbing and erratic arc; too long adds resistance heating and spatter. Check it at the start of every job because operators shorten it unconsciously while repositioning.

Do I need a respirator when doing flux core welding?

Yes, as part of a full respiratory protection program. The NIOSH Pocket Guide lists welding fumes as a potential occupational carcinogen with lung cancer as the cancer site and no OSHA PEL for the mixture itself, and NIOSH recommends respirators above the REL or at any detectable concentration where no REL exists. Local exhaust or portable fume extraction plus correct eye and skin protection should come first.

Is flux core welding stronger than stick or MIG?

Strength is a property of the weld metal and the procedure, not the process name, so the honest answer is it depends on the filler metal classification and the code requirements. For critical structural work, E71T-8 with its mandated toughness is the appropriate choice, while E71T-11 carries no toughness requirement and is not used for critical welds.