5 Types of Wire for MIG Welders

Choosing the proper MIG wire allows for more flexibility in the welding that you accomplish. There are several types of MIG wire to choose from based on the cost, the project you want to finish, your expertise level. All these wires have their own benefits and work best on different projects.

Let’s take a look at five main types of wires that work well for MIG welding. They vary based on how well they will work for the beginner and how expensive they are. We’ll cover each in detail and explain their differences. 

The Different Types of Wire for MIG Welders

Most welders who think about doing MIG welding think about hardwire. This is a good option, but not the only one you can make for your welding needs. There are many other types of wire you can choose.

We’ll outline 5 great choices for you below.

Hard Wire: Easy, Beginner Friendly Wire

Hard wire is one of the most used wires in MIG welding. Most of the fabrication shops that you visit will have their machines set up to use hardwire. It is simple to use, beginners find it user friendly, and it is affordable compared to other options. 

Hard wire is beneficial because it provides several techniques and patterns that you can use with the same penetration. For someone just learning how to weld, this simplicity is nice. There are also several types of hard wire based on its hardness and what you want to get done with it. 

There is also less slag involved with hardwire so it is faster to process, making your welding that much more efficient in the process. You can basically choose any position you want when welding with this type of wire, which adds to how easy it is to use. 

Reasons to use hard wire:

  • Easy for beginners to learn how to use
  • Affordable compared to other types of wires. 
  • You can weld in any position you want.

Reasons to avoid hard wire:

  • This wire does not penetrate as well as some other processes
  • If you use low voltage with this wire, it can lead to your welding being cracked. 

If you are going to work with any type of wire, then it is likely you will start with hardwire. It is versatile and one of the easier metals to get things done. It allows for a few mistakes that are easy to iron out if something goes wrong, making it a great place to start as a beginner. 

Gasless Flux Core Wire: A Wire with Flux Found Right Inside 

This option is nice because the flux has been designed right into the wire so there is no need for a shielding gas. This is similar to what we find in stick welding because you do not need any gas cylinders. You can just get the machine started and do your welding. 

This process is a little messier compared to the other options because there is quite a bit of spatter and slag. This makes it hard for beginners to get started. However, this is a strong and durable method to use so may be worth the time. These welds also produce a really beautiful design and it is available for a good price. 

If you want to work on your own personal project but do not need to have a high-quality product at the end, then this type of welding wire can do the job for you. Just make sure you have a good standard wire brush to help as well as an angle grinder. After you do each weld, clean it off to look over the bead and ensure it matches what you want. 

Reasons to use gasless flux core wire:

  • Provides a welded piece that is durable and strong. 
  • Perfect for your own projects. 
  • The design looks beautiful when done. 

Reasons to avoid gasless flux core wire:

  • The process is more complicated. 
  • There is a good deal of mess with these. 
  • Need to clean up often. 

If you plan to use this type of MIG wire, be ready for a mess. You should wear some protective gear to help you be safe while using this wire. With other wires this mess usually means you are doing something wrong, but this is actually pretty normal when using the gasless flux core wire. 

Dual Shield Flux Core Wire: The Best of Both Worlds for MIG Wire

If you need a really strong welding wire, then this is the perfect option. You would use this one just like the gasless flux core but with the addition of a shielding gas as normal. 

The reason for doing this is to provide two shielding properties during the weld, making it stronger and making it a favorite with all welders. The beads are also wider than other welds and the arc can go through rust. 

Dual shield welding wire can help avoid issues like rod stubs falling on the floor or the need to replace the rods all of the time. This makes bean fabrication more productive than before. This is also the type found for wires that are larger in diameter. It is not uncommon to use sizes like .040” and .045” for this process.  The voltage settings at 30 are not uncommon and you may need a power outlet of 480V too. As a hobby welder, you will need a smaller diameter of this kind of wire to get it to work. 

Reasons to use dual shield flux core wire:

  • Stronger than other options. 
  • Can make welding more productive
  • Uses two processes to help it stay together

Reasons to avoid dual shield flux core wire:

  • Relies on really thick wiring, which is sometimes hard to use as a beginner. 
  • Uses two processes so takes more time. 

This wire type gives you a lot of extra strength. It relies on two different methods to keep it strong; both the flux put into the wire and the use of a gas like argon to make it better. If you are working on a project that needs a lot of strength, then the dual shield flux core wire is the best option. 

Aluminum Wire: A Soft MIG Wire

Welders need to have special skills and different equipment when they want to weld with aluminum. Aluminum is a lot softer than some of the other options, so it is almost impossible to run it through some of the original parts of your MIG gun. Often welders will find that argon works the best for this, but if you need a better puddle to work with, then a little helium will suffice. 

Most of the manufacturers who sold this wire made it on a small spool, usually just one pound. If you purchase a spool machine that can be paired with the right MIG machine, you can add the aluminum wire spool to it and can start their welding. This setup is the best because the travel distance for the metal is lower, preventing any issues with jamming. 

If you did this with the original MIG cable, which is usually four to five feet compared to 10 inches, then the aluminum would jam up and cause issues. Aluminum wire that jams will get crinkled and is nearly impossible to fix. 

Reasons to use aluminum wire:

  • Aluminum is soft and easily pliable.
  • Can have a shorter setup that saves space. 
  • Works with helium and argon gas. 

Reasons to avoid aluminum wire:

  • Takes a special setup to get the work done. 
  • If you do make a mistake, it is hard to fix. 
  • The spool for it is a lot smaller than other options. 
  • It does not behave like the other wires so is hard to learn. 

This option is not usually the best one. If you need to work in a smaller area to get things done or you need something easy to practice with, then this one may be suitable. However, it is not as strong or high-quality as some of the other MIG wires, so it is usually best to avoid it. 

Stainless Steel Wire: The Most Expensive Choice for MIG Wire

Stainless steel is quickly becoming an MIG process that is popular for many welders. This is a similar material to hardwire, but you may notice the bead is a little more sluggish compared to others. Beginners may notice that working with this option is a little harder to manipulate and push around. 

With stainless steel, you may notice that the puddle heats up very fast. If you are not able to keep up with the travel speed, which is very fast, then your material may burn. This type of wire is really expensive, so it is never a good idea to mess with it or let it get wasted. You will need to charge your customers more for the finished product to make it worth it. 

However, stainless steel welding products can look amazing. While beginners should be careful about this option, it can make for some amazing options when you are all done. Welding with this material can be enjoyable, but it is expensive and takes a lot of practice. 

Reasons to use stainless steel wire:

  • A lot of fun to learn how to use
  • Can make amazing looking products when done. 

Reasons to avoid stainless steel wire:

  • More difficult to mold compared to other materials. 
  • Costs more so is expensive to mess up on. 

Stainless steel is one of the most expensive options that our out there for MIG wire. Many beginners will find it is too difficult to work with for the amount that it costs. If you have done welding for some time and want something new, stainless steel can be a lot of fun. Just be aware of the price. 

What to Consider When Choosing the MIG Wire?

Often welders focus on the cost of their wire when doing the MIG welding. This is an important consideration because the wire cost is between 10 to 15 percent of the total cost of welding. A welder needs to choose the right kind of wire because if they choose incorrectly, they will end up with a bad weld. 

The right wire makes all the difference in your project. You need to evaluate what types of wire to use for the best results, especially with a large project. Getting it wrong will lead to a lot of costly rework and your price will go way up. You may even need to reorder the wire and start the project over again. 

If you are uncertain about the type of wire to use, even with some research, you can do a test sample. Doing just a little welding with a few types can help you evaluate these options to decide which is the best one. 

Some things to consider when choosing the wire includes:

  • The cost: If there are two wire options that seem like they will do the right job, you can keep costs down by choosing the least expensive. 
  • The size you need: Pick a wire based on the size that you need for your project. 
  • The project you work on: Each project will lend itself better to one kind of wire over another. 

Consider the packaging you use as well. You should go with an option that will be used up with your work in about five weeks. The wire will rust if you leave it there for too long. Read the instructions that come with it so you don’t accidentally waste an entire spool due to rust or spoilage.

How Do I Know What Size MIG Wire to Use?

The size of wire that you need will depend on the product you want to undertake. Those that have large gauge thickness and need to handle more work will need thicker wire. While some smaller projects can get by with less. 

When you are talking about the wire diameter of MIG, bigger is almost always the best choice. There are different rules, but everything that is less than 1/8” is considered thin and should use a small diameter wire. Anything above that is considered thick. 

For wire diameter, anything that is less than .045” is small and all other choices will be big. These are oversimplifications but can help you choose the right wiring that is right for you. For example:

  • If the diameter is .035”, it is set up for a wire speed of 325 IPM and a travel speed of 24 IPM. 
  • If the diameter is .045”, it is set up for a wire speed of 200 IPM and travel speed of 24 IPM. 
  • If the diameter is .052”, it is set up for a wire speed of 140 IPM and a travel speed of 24 IPM. 

These are some generalizations to help you see how the MIG wiring works so you can choose the right one for your project. When you choose the wire thickness, you should always consider how thick the metal is that you plan to weld. When you pick out a wire, there will usually be a wire thickness chart that you can utilize for your project. 

In many cases:

  • 0.24 width works well with the 18 to 24 ga.
  • .030 works well for anything from 22 ga to 1/8
  • .035 is best for ½ to 18g
  • .045 width works for the ½ to 14ga. 

This is a general rule to follow to help you pick the right width, but there may be other circumstances which influence your choice. Pick the right wire and width for your project and all will go smoothly.

How Can I Tell What Type of Wire I Have?

If you have a spool of MIG wire and are not sure what type, it is important to do some research to see what kind and how you can use it. Since hard wire is the most common type, that is a good first guess. 

However, guesses only get you so far, so here’s some other things to consider:

  • Check if the wire is magnetic. Some metals are magnetic and others aren’t, so it’s a good first step. Stainless steel is magnetic, but aluminum is not, for example.
  • Test the durability of the wire. Aluminum is soft while dual flux and steel is stronger. 
  • Look at the length. If a spool is less than a foot, it is most likely aluminum since it is rarely sold in lengths longer than that. 
  • Dual shield welding wire is the thickest, so if the wire looks difficult to work with, this is most likely the type. 

Getting Your MIG Wire

Choosing the right wire is an integral part of being successful in a project. Using the wrong wire for the wrong purpose can often mean that not only will you be frustrated while welding, but your project will just come out messy, incomplete, flawed, or all three at the same time.

Remember that hard wire is your go-to for almost any project as a beginner. Get comfortable with it first before you attempt to branch out into more difficult types of MIG wire, like aluminum or gasless flux core.

https://www.wisegeek.com/what-is-mig-welding.htm

Alexander Berk

A bit about myself: I am a certified international welding engineer (IWE) who worked in different welding projects for TIG, MIG, MAG, and Resistance Spot welding. Most recently as a Process Engineer for Laser and TIG welding processes. To address some of the questions I frequently got asked or was wondering myself during my job, I started this blog. It has become a bit of a pet project, as I want to learn more about the details about welding. I sincerely hope it will help you to improve your welding results as much as it did improve mine.

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