.030 vs .035 Flux Core Wire: Which Is Best Flux Core Wire & How to Choose?

When you are new to welding identifying the right welding wire to use can be tricky, especially with all the different kinds of welding wires available to you. And the seemingly unending debate of .030 vs .035 flux core wire and .030 vs .035 welding wire doesn’t help.

Knowing which wire does what best is what will help you choose. But before we get to compare these wires, let’s go over some basics.

Recommended Best .030 and .035 Flux core Wire

ImageModelPriceWire Size
Blue Demon E71TGS .030 X 10LB Spool Gasless Flux Core Welding WireBlue Demon E71TGSCheck Price0.030
YESWELDER Flux Core Mig Wire, Mild Steel E71TGS.030-Diameter, 10-Pound SpoolYESWELDER Flux Core WireCheck Price0.030
Blue Demon E71TGS .035 X 2# Spool Gasless Flux Core Welding WireBlue Demon E71TGSCheck Price0.035
LINCOLN ELECTRIC CO ED030584 .035'NR-211 Fluxco Wire,BlackLincoln ElectricCheck Price0.035

What is flux core wire?

Used in MIG welding, a flux core wire is a type of welding wire that has a flux coating. There are two types of flux core wire, self-shielding and gas-shielded. As the name suggests, gas-shielded flux core wire requires an external shielding gas.

The flux coating of gas-shielded flux core wire solidifies faster than the molten pool of the weld material. The result is a sort of a shelf that holds the molten pool, which aids in vertical or overhead welding.

Self-shielding flux core wire does not require an external shielding gas. These types of wires produce a shielding gas when the flux-coating is burned.

Flux core wire uses

Due to the fact that flux-cored wire does not require shielding gas, it is used for outdoor welding. With solid wire, outdoor MIG welding can be problematic. Also, flux core wires make welding machines more portable as you do not need external gas shielding.

Gas-shielded flux core wire is used for welding thicker metals. Moreover, they are suited to out-of-position welding applications.

Benefits of flux core wire

The popularity of these types of welding wires points to them having countless benefits. Flux core wires allow for a higher deposition rate. Furthermore, these types of wires can be used outside in windy conditions.

Also, flux core wires are more tolerant of rusted or dirty metals. Thus, you can weld rusted or dirty metals with these wires.

Can I use shielded gas with self-shielding flux core wire?

This is something you probably have thought about. As you might have guessed, doing this will lead to a poor weld. When the chemicals in your flux core wire do not react with the air, they end up contaminating your weld, which leads to a poor weld and cracking.

flux core wire speed and voltage chart

flux core wire speed and voltage chart

Differences Between The .030 And The .035 Flux Core Wire

Now that we have covered the basics, let’s get into the meat of the matter, which is better .030 vs .035 flux core wire. First, it is important to note what these two numbers mean. The numbers .030 and .035 refer to the diameter of a welding rod.

Sometimes written as .35 and .30, these two numbers reflect the thickness of a rod. As such, the .035 electrode is .005 inches thicker than the .030. So what does the mean?

Essentially, thicker rods require a higher amperage compared to thinner rods. As such, a .035 electrode will require a higher amperage. Also, the 0.35 flux core wire can handle thicker sheets of metal compared to the 0.030.

However, the 0.035 welding wire struggles when it comes to welding thiner metals. It is best suited to welding metals that have a thickness of more than 16 gauge. The 0.030 flux core wire is the right option for welding thiner metals.

Wires with a thicker diameter burn hotter and have a deeper penetration. For instance, a 0.45 flux core wire will burn hotter than a 0.35 flux core wire. For welding, a ½ inch thick steel metal a 0.45 flux core  wire will be a better choice.

.030 vs .035 Flux Core Wire - Which one is better for what?

Let’s settle the debate of which is better 030 vs 035 flux core wire. While some will say one is better than the other, that isn’t true. It all depends on what type of metal you typically weld.

If you typically weld metals of below ¼ inch in thickness, then the 0.35 will be ideal. On the other hand, if you usually weld thinner metals. However, the difference in metal thickness is very small.

What determines which you to use is the type of flux core welder you have. So what size wire for welder? Typically the 0.30 flux core  wire will work best with 210V and under machines. Contrastingly the 0.35 flux core wire will work best with 250v and over machines.

Best .030 flux core wire Reviews

So which .30 flux core wired brands and models do I think are the best? Based on my experience, I would have to go with these two.

Blue Demon E71TGS .030 X 2# Spool Gasless Flux Core Welding Wire

The Blue Demon E71TGS is a staple of many welders and for good reasons. I use a Lincoln 110V welder and this.30 Welding Wire has been great so far. It is capable of welding galvanized roofing sheets as well as auto body sheet metals.

What I loved about this wire is how smooth it runs. It also lays down a great bead and there is very little cleanup required after welding. And since it’s a flux core wired, there is no need for external gas containers. It also produces low smoke and spatter.

INEFIL ER70S-6 .030-Inch on 10-Pound Spool Carbon Steel Mig Solid Welding Wire

Inefil is not the most well know brand of welding wire out there. But the company does make great welding wires, one of which is the ER70S-6 0.30-inch wire. I have bought several spools of this wire and are pleased with the outcome.

It is wound to the spool and feeds smoothly without jerking. One common problem with cheaper wires is inconsistent wire diameter which causes feed problems. I was pleased with the diameter consistency of this ine flux core wire.

Overall this wire starts well and produces a clean spatter-free weld. On top of this it does create good looking weld beads. The color and texture of the weld beads is something that I was impressed with.

Recommended Best .035 flux core wire

When it comes to the thicker .35 welding wire, I have some preferences as well. My two top best welding wire in this category are;

Blue Demon E71TGS .035 X 2# Spool Gasless Flux Core Welding Wire

Blue Demon is one of my favorite welding wire brands. Thus it makes sense that I would purchase the company’s .035 flux core welding wire as well. There is no much difference between this and the 0.30 version of the wire.

As such, it is an all-position gasless flux core wired that is great for welding galvanized roofing sheets. Furthermore, it does come in handy when you want to do some auto body repair works. It’s, of course, thicker than the 0.30 flux core wire can weld slightly thicker metals.

All the same, it maintains all the good things that we have come to expect from all Blue Demon wires. Also, it is an excellent choice for welding carbon steel.

LINCOLN ELECTRIC CO ED030584 .035 "NR-211 Fluxco Wire

Slightly cheaper than the Blue Demon, the Lincoln Electric ED030584 is another great .035 wire. Lincoln products are famous for their quality, and this wire is no exception. This welding wire delivers a clean weld with an excellent bead appearance.

Given its self-shielding flux core wire, it works well in moderate wind conditions. Its fast freezing characteristics make it a good option for most welding applications. And while it does produce some bit of slag, it’s easy to remove.

How To Choose Best welding wire

When shopping for welding wire, there are several things to keep in mind. These are;

Rod material

The best welding wires are those that are made from the same material as the metal you are welding. As such, the best MIG wire for mild steel is made from mild steel. Thus when shopping for a welding wire to weld mild steel stick to those made from mild steel.

Spool size

Welding wires come in a variety of spool sizes. The spool size you select will be dependent on the type of welding machine you are using. Therefore, not all machines can accommodate a 10-pound spool.

It is essential to check the spool size that your welder can accommodate. Alternatively, you can purchase an adapter to make your welder accommodate a larger spool size.


When welding mild steel, you need to use DCEP or direct current electrode positive. Therefore, when shopping for a welding wire for mild steel, go for one that is capable of DCEP welding.

Wire size

Wire size also depends on the type of welder you are using. You can either opt for a 0.024, 0.030 0r 0.035 inch wire sizes. Some welders are compatible with 0.030-inch wires while others work well with 0.035-inch wires.

How to maximize the lifespan of welding wires

There are several tips on how to increase the lifespan of your mild steel welding wire. The most useful is to clean the tips after use. This will help get rid of any contaminants.

Storing the rods in a moisture-resistant plastic bag is also recommended. From the reviews, several rods come sealed in moisture resistant bags.


When choosing which welder to use between .030 vs .035 flux core wire, you need to consider the metal you are welding and your welding machine. These two welding wires are not so different and can be used for most welding applications.

But for most general-purpose welding the .030 flux core wire is what to use. The .035 may require a little bit more power, which your welder may not be up to. In conclusion, the debate of .030 vs .035 welding wire doesn’t have a clear winner. It all depends on your needs.

Last update on 2021-04-14 / Affiliate links / Images from Amazon Product Advertising API

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