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Best Flux-Core Wires of 2021

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Flux-core wires free you to weld anywhere and in any condition.

Flux-core wire is the best material to use when welding dirty or rusty steel. It also makes welding outdoors possible.

The best flux-core wire improves the tensile strength of the weld and helps to bond metal to metal in difficult circumstances.

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Model
Product Comparison Table
Features
Product Image of the LINCOLN ELECTRIC CO ED031448 .030 NR-211, Lb Spool, Inner Shield Flux-Core Welding Wire,Black
Best All-Around Flux Core Wire
Lincoln Electric Flux-Core Wire
  • Made from strong mild steel
  • 0.030-inch gauge
  • Can spot weld
Product Image of the Forney 42300 Flux Core Mig Wire, Mild Steel E71TGS.030-Diameter, 2-Pound Spool, Silver, Pack of 1
Best Flux Core MIG Wire
Forney Flux-Core MIG Wire
  • Low spatter
  • High tensile strength
  • Made of mild steel
Product Image of the YESWELDER Flux Core Gasless Mig Wire, Mild Steel E71TGS.030-Diameter, 2-Pound Spool
Best 0.030-Inch Flux Core Wire
YESWELDER Flux-Core Welding Wire
  • High tensile strength
  • Vacuum-sealed packs
  • Useful for multi-pass welding
Product Image of the INETUB BA71TGS .030-Inch on 2-Pound Spool Carbon Steel Gasless Flux Cored Welding Wire
Best Gasless Flux Core Wire
INETUB BA71TGS Flux-Core Wire
  • Made of carbon steel
  • High manufacturing standards
  • Non-porous
Product Image of the WeldingCity E71T-GS Gasless Flux-Cored Mild Steel MIG Welding Wire 0.035' (0.9mm) 10-lb Spool
Best 0.035-Inch Flux Core Wire
WeldingCity Flux-Core Welding Wire
  • 0.035-inch diameter
  • 10-pound spool
  • Better penetration
Product Image of the Blue Demon E71TGS .030 X 2# Spool Gasless Flux Core Welding Wire
Best for Rusty Metal
Blue Demon Gasless Flux-Core Wire
  • Ideal for dirty & painted material
  • All-position wire
  • Welds carbon steel

What Is a Flux-Core Wire Used For?

A flux-core wire adds molten metal to the weld pool to increase the weld joint’s tensile strength, no matter what the conditions. It enables you to weld outdoors in challenging circumstances without the use of shielding gas.

It also means that repairs to machinery can happen on the spot because flux-core wire works just as well in clean conditions as it does on dirty or rusted metal. Plus, if you are welding vertically or overhead, flux-core wire solidifies faster, making it possible to achieve these welding angles without losing the weld pool.

How To Choose the Best Flux-Core Wire

Several factors make up the ideal flux-core wire. We run through some key aspects to consider.

How You Use It

The conditions you will be welding under, and the type of material also play a role in deciding what flux-core wire you will need. Some only weld clean steel, while others are suitable for on-site conditions.

Knowing which wire you need is part of the skill of an experienced welder. If you are welding stainless steel, you need a stainless steel wire, and for steel, you need a steel wire. The flux-core should match the base metal to ensure the best bond and highest tensile strength.

Plus, you wouldn’t want your welds rusting if you use steel wire on a stainless steel base metal. Welds are notoriously weak at resisting corrosion and oxidation unless treated.

Diameter Range

Wire sizes vary, depending on your welding machine’s amperage, the type of plate you are working with, and the size of the feed wheel and nozzle you have. The good news is that the nozzles can be adapted to fit, but the amperage dictates the thickness of the flux-core wire.

A welder with a lower amperage needs a wire with a smaller diameter. Less amperage translates as less power. The reverse is true of a larger amperage, because if the flux-core is too thin it will melt faster and become difficult to control.

Spool Size

The amount of welding you undertake and the capability of your welder will determine the size of the spool of flux-core wire. Larger spools are often cheaper overall, but not every flux core welder can accommodate the increased spool size.

Make sure you check the spool size before committing to buy the flux-core wire.

How Much?

Flux-core wire varies in price, depending on the manufacturer and the type. Also, spool sizes dictate the price, with an initial higher cost for larger spools but a reduced cost when compared to the price per inch.


The Best Flux-Core Wires of 2021

There are multitudes of flux-core wires available on the market. Choosing the best one was a challenge.

1. Lincoln Electric ED031448 Flux-Core Welding Wire

Best All-Around Flux Core Wire

For all-around performance, this Lincoln Electric flux-core wire is pretty hard to beat. It gets a high rating on a well-known online site too. So, what is so great about it?

It is made from strong mild steel, and it is ideal for MIG welders. It comes in reels of 1.15 pounds, and the diameter is 0.030 inches, so it is better suited to welding machines with lower amperage.

This is also an ideal candidate for on-the-spot welding tasks involving dirty or rusted metal, thanks to the freezing characteristics of the wire.

Pros

  • Ideal for MIG and stick welding.
  • Great brand name.
  • 0.030-inch gauge.
  • Ideal for rusted and dirty metal.

Cons

  • Small reels.
  • Better with low amperage machines.

Additional Specs

Weight (pounds) 1.15
Dimensions (inches) 10.5 x 5.75 x 4.25
Tensile strength 70,000 PSI
Diameter (inches) 0.030
Material Mild steel
Price $

2. Forney 42300 Flux-Core MIG Wire

Best Flux Core MIG Wire

This Forney flux-core wire is suitable for all welding positions, and like the Lincoln Electric wire, it is ideal for using on rusted, dirty and painted metal surfaces. This makes it the perfect wire to have handy for on-the-spot repairs like farm machinery and construction sites.

It is a 0.030-inch diameter wire, suitable for single-pass applications with a high travel speed. It comes in 2-pound spools, has a tensile strength of 79,000 PSI, and it produces minimal spatters.

This wire is made of mild steel and is suitable for MIG welding. You can add argon gas to reduce the spatters further, but it works just as well without shielding gas.

Pros

  • Low spatter.
  • High tensile strength.
  • Suitable for MIG welding.
  • 2-pound spools.

Cons

  • Suited to low amperage machines.

Additional Specs

Weight (pounds) 2
Dimensions (inches) 1 x 4 x 4
Tensile strength 79,000 PSI
Diameter (inches) 0.030
Material Mild steel
Price $$

3. YESWELDER 0.030-Inch Flux-Core Welding Wire

Best 0.030-Inch Flux Core Wire

This mild steel wire gives good coverage, has low spatter and produces slag that is easy to remove. It also has low porosity and provides a good bead appearance. Unlike other flux-core wires, this is suitable for single and multi-pass welding. It also operates in any welding position.

You can use this wire on multiple applications, including butt, lap and fillet welds, and it is equally at home welding clean and dirty metal, making it ideal for on the spot repairs.

This wire comes in 2-pound reels and has a tensile strength of 79,000 PSI. Plus, it comes in a vacuum-sealed pack, so that it can be stored for a long time without the risk of the wire going bad through moisture penetration.

Pros

  • High tensile strength.
  • 2-pound reels.
  • Vacuum-sealed packs.
  • Useful for multiple applications.

Cons

  • Made in China.

Additional Specs

Weight (pounds) 2
Dimensions (inches) 4.21 x 4.13 x 2.12
Tensile strength 79,000 PSI
Diameter (inches) 0.030
Material Mild steel
Price $$

4. INETUB BA71TGS 0.030-Inch Flux-Core Wire

Best Gasless Flux Core Wire

This INETUB flux-core wire is Italian and produced to the highest standards. It comes as a 2-pound spool, has a diameter of 0.035 inches, and has full slag coverage. It is also a low spatter wire with easy slag removal when cooled.

It is also porosity-free and gives a good bead appearance. This wire is suitable for all welding positions, as well as single and multiple pass welding. It has a tensile strength of 82,700 PSI, making it one of the best in the business. This flux-core differs from the others featured because it is a carbon steel wire rather than mild steel.

Pros

  • Carbon steel.
  • High manufacturing standards.
  • Non-porous.
  • 0.035-inch diameter.
  • Single or multi-pass.

Cons

  • Quality control issues.

Additional Specs

Weight (pounds) 2
Dimensions (inches) 3.94 x 1.85 x 3.94
Tensile strength 82,700 PSI
Diameter (inches) 0.030
Material Carbon steel
Price $$$

5. WeldingCity E71T-GS Flux-Core 0.035-Inch Welding Wire

Best 0.035-Inch Flux Core Welding Wire

If you like buying your flux-core wire in bulk, this Welding City 10-pound spool is the ideal purchase. And it’s an all American company. The welding wire comes wrapped in a vacuum-sealed pack to keep the flux-core from going bad and to prevent moisture from penetrating.

This is the first 0.035-inch diameter wire to feature, so it is suited to a welder with higher amperage. It also means you get a deeper penetration thanks to how the wire melts and creates a larger weld pool.

Like the others, it is mild steel and has a tensile strength of 70,000 PSI. Plus, this wire works on single pass welds rather than multiple passes.

Pros

  • 0.035-inch diameter.
  • High tensile strength.
  • 10-pound spool.
  • Better penetration.

Cons

  • Single-pass only.

Additional Specs

Weight (pounds) 10
Dimensions (inches) 8.4 x 8.4 x 2.5
Tensile strength 70,000 PSI
Diameter (inches) 0.035
Material Carbon steel
Price $$$$

6. Blue Demon E71TGS 0.030 Gasless Flux-Core Wire

Best Flux Core Wire for Rusty Metal

This Blue Demon wire is great if you want to weld galvanized roofing sheets and car body parts. It is an all-position, single pass flux-core wire, even vertically and overhead.

Typically, this wire is used to make lap and butt joints on sheet material, but it is also ideal for welding dirty and painted metal. This makes it a great accessory to have around the ranch or farm for on-the-spot welding repairs.

It has a tensile strength of 70,000 PSI, and it operates on a DCEN with a straight polarity.

Pros

  • High tensile strength.
  • Ideal for dirty and painted material.
  • All-position wire.
  • Welds carbon steel.

Cons

  • Single-pass only.

Additional Specs

Weight (pounds) 2.13
Dimensions (inches) 4 x 4 x 2
Tensile strength 70,000 PSI
Diameter (inches) 0.030
Material Not stated
Price $$

Flux-core Wire Comparison Chart

Product Best Weight Dimensions Tensile strength Diameter Material
Lincoln Electric Flux-Core Wire All-Around 1 lb 10.5 x 5.75 x 4.25″ 70,000 PSI 0.030″ Mild steel
Forney Flux-Core MIG Wire MIG Wire 2 lbs 1 x 4 x 4″ 79,000 PSI 0.030″ Mild steel
YESWELDER Flux-Core Welding Wire 0.030-Inch 2 lbs 4.21 x 4.13 x 2.12″ 79,000 PSI 0.030″ Mild steel
INETUB BA71TGS Flux-Core Wire Gasless 2 lbs 3.94 x 1.85 x 3.94″ 82,700 PSI 0.030″ Carbon steel
WeldingCity E71T-GS Flux-Core Welding Wire 0.035-Inch 10 lbs 8.4 x 8.4 x 2.5″ 70,000 PSI 0.035″ Carbon steel
Blue Demon Gasless Flux-Core Wire Rusty Metal 2 lbs 4 x 4 x 2″ 70,000 PSI 0.030″ Not stated

Flux Core Wire FAQs

Which Is Better 0.030 0r 0.035 Flux Core Wire?

It’s all a question of thickness to answer this. 0.035 flux-core wire is better at welding metal with a 16 gauge or more, while 0.030 wire is suited to thinner metals. Both are as good in their own applications.

How Thick Can Flux Core Weld?

Flux-core wire generally welds metal to a thickness of around 0.25 inches. It all depends on the welding machine you are using and the amperage.

Can I Use Flux Core Wire With Gas?

Flux-core wire does not require gas to shield the weld. It does the same job as gas during the welding process, releasing a shielding gas as the wire melts. However, you can use shielding gas with flux-core wire, but it is completely pointless. It won’t produce inferior joints, but it will waste your gas.

Is There a Flux Core Aluminum Wire?

There is no such thing as a flux-core aluminum wire. You can buy aluminum wire, but an online search brings up a lot of confusing results. It is deceptive that products boast that they are aluminum welding wire, when in fact, they are soldering and brazing filler instead.

Welders run too hot for this wire, and it would be unsuitable if you tried to use it. It would simply burn out.

Does Flux Core Wires Go Bad?

Flux-core wires go bad when they are exposed to damp air. Contaminants enter the wire, and it deteriorates. Store wire in a seal-tight container in warm conditions to avoid any moisture getting into the wire.

Do You Push or Pull Flux Core Wire?

You should always use a dragging or pulling technique. Flux-core welding creates a lot of spatters, and as the saying goes, “Where there is slag, you drag.”


Down To The Wire

Flux-core wire frees you to weld in all conditions without worrying about shielding gas. It means you can make on-the-spot repairs to keep your farm machinery going or fix something to avoid delays.

It also means you can mend dirty and painted metal, increasing your versatility and welding range.

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About the Author

Mark Weir

Mark spent 24 years working in real estate, so he knows his way around a home. He also worked with contractors and experts, advising them on issues of planning, investments, and renovations. Mark is no stranger to hands-on experience, having renovated his own home and many properties for resale. He likes nothing better than seeing a project through to completion.

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