The Guide to MIG Welding Wire Selection

Welding wire type
GMAW wire

Welding is basically a process of joining two metal pieces, there are various welding methods being adopted by professional and the most common types of welding are Stick, TIG and MIG welding. When it comes to MIG welding, it uses a combination of heat and an electrode wire to create a molten pool to fuse two pieces of metal together. In MIG welding, you can easily join a variety of metals, and the type of wire used is determined by the type of metal being welded. Hence it is important to choose the right kind of wire during MIG welding to get optimal results. In this article, we’ll take a look at how to select the best welding wire along with the types of welding wire etc.

When it comes to welding, small and medium businesses always look at bringing down the costs as the costs of raw materials, energy costs along with the costs associated with labor have risen considerably, hence, it is imperative for the companies to bring down the production costs by reducing the costs involved in the materials or any other means.

In the manufacturing industry, welding is a major function and the welding wires become the first casualty in their cost-cutting mechanism. This can backfire in a great way as it may produce low-quality welds that need to be re-welded. And that why choosing the best welding wire by seeing What is MIG wire made of and what type of metals are used in welding etc. There are many welding wire types available in the market, right from cheap to expensive wires, it is important you choose a branded wire that gives you the desired results and a strong weld which will last a lifetime.

If you are looking for a great wire, I would recommend you this one:
That is the one I use and it is really good.

Selecting the Right Wire Metal

In MIG welding, when it comes to choosing the type of wire, it largely depends on the metal being welded, most of welders choose a filler metal that is of the same type metal to be welded, so that if you are about to weld stainless steel, then you need to go for a welding wire that is made up of stainless steel. The most common welding wire types used are:

The most common welding electrode wires used by welders generally come with a thickness between 0.023 – 0.045, when choosing welding wire for heavy industrial applications, the wire size will be even thicker than the above.

Nowadays, MIG welding wire manufacturers are producing wires that include many other elements like manganese, silicon and titanium along with the primary metal. The reason other elements are included in the wire is to help in deoxidizing the weld and create a strong and stable arc. Steel electrode wires come coated with some percentage of copper to avoid oxidation. And the percentage of these elements added may differ from wire to wire as it plays a large role in the hardness of the filler itself. Before choosing the welding wire, always look at the primary metal even though the wire comes with a lot of these extra elements. If you are not sure about which type of wire to choose, you can always seek the help from the supplier as they would guide you in the right direction. Or else you can always take a look at the chart which is being included with many welding machines that provide information about the right kind of welding wire to be used for different metals.

Selecting the Right Wire Thickness

Apart from the type, the thickness of the wire or the MIG wire sizes plays a great role in determining the quality of the welding output. When choosing the wire thickness, consider the thickness of the base metal to be welded as it can help you come to a proper understanding about the diameter of the electrode wire needed. Most manufacturers provide you with detailed wire thickness charts that will help you choose the right kind of thickness for your welding purposes.

Many come up with the question about What is MIG wire made of and the answer is the wires come with various compositions and it is up to you to choose the right composition based on the metal being welded. When it comes to welding mild steel, the best MIG wire for mild steel is the ER70S-6. For very thin sheet metal the best wire size would be 0.24 inches. You can also use this table to determine the size you need.

Material .024 .030 .035 .045
24 ga *      
22 ga * *    
20 ga * *    
18 ga * * *  
16 ga   * *  
14 ga   * * *
1/8   * * *
3/16     * *
¼     * *
5/16     * *
3/8     * *
1/2     * *

General errors When Choosing GMAW Wire

MIG wires come in many varieties because different metals and applications require different size wires. Take for example, the case of ER70S, popular wire series used by many welders for mild steel joints comes in several variants including ER70S-3, ER70S-6 where ER70S is the perfect choice for welding base materials that are both oil and contaminant free. ER70S-6 is used to weld that comes with surface contaminants and mill scales. ER70S-3 is much cheaper than ER70S-6, and it is important to choose the right kind of welding wire variant based on your welding requirements. We have even seen examples where people weld advanced high strength steel (AHSS), with a wrong filler, and if electrode wires with correct matching properties are not used, then there is great chance that they end up with a defect weld.

Selection criteria for choosing the best MIG wire

Even though the cost of wire used in MIG welding will not amount to even 10-15% of the total welding cost, it is still important to choose the right wire as any wrong selection may lead to a bad or incomplete weld. Hence, before taking up a big welding job that requires welding hundreds of joints and before ordering electrode wire in bulk, it is important to evaluate what’s the best kind of wire to be used that will produce optimal results. Any misunderstanding here may lead to a lot of rework and cost escalation and even ordering the proper set of wires again. It is even better to test a sample piece to come to a better understanding of the type of wire that produces the best results before going for bulk orders.


Another aspect to be thought about while choosing welding wire is the packaging option. Make sure to choose a packaging option that gets used up in just 5-6 weeks as it would take a lot of floor space and even rust if left for too long.

Make sure you read the instruction on the package to avoid ruining the wire spool between the projects if you are a hobbyist. It is important to keep the wire in warm and dry to avoid oxidization. You can put the filler in the zip bag between the projects and even throw in some silica packs to reduce the humidity inside the bag.


It might feel overwhelming to choose a new spool of wire, but in most cases, for home and hobby welders regular 0.30” would to the trick to marry regular steel. Even when welding sheet metal like car body panels, with a little practice, It is possible to avoid burn through and warping with this type of welding wire.

What’s your take on welding wires and different thicknesses? Drop us a comment below!

Categories MIG