What Size MIG Welding Wire Do I Need?

MIG wire comes in different sizes and selecting the right size is essential to achieve quality welds. Inappropriate wire sizes can cause burnback, wire jamming, and poor penetration, to name just a few. The welding wire, shielding gas and welding equipment must be suitable for the application, here at Engweld we have weld specialists who can help you understand this.

The wire size should match the drive rolls. If it doesn't, you'll have to keep adjusting the feed speed because of either not enough or too much grip. The same applies to the contact tip size and torch liner.

Using the right MIG wire and tension is important. Too little tension makes the wire slip, while too much tension deforms it. Both of these are far from ideal when MIG Welding. Then you must take into account the wire that you are using, with softer, stiffer, and very soft wires available, you must ensure that you are using suitable drive rolls, with V-knurled rollers, V-groove rollers, and U-groove rollers all available.

There are several factors to consider when choosing the MIG wire size. The primary consideration is the desired result, whether it is manual or robotic welding, the skill set available, the standards/codes being worked to, and the overall efficiency factors of the selected process.

0.6mm to 0.8mm MIG wire is used for thinner materials that are less than 5mm thick. For thicker welding materials like 5-10mm, the preferred diameter for MIG wire is 1.0mm or 1.2mm. The general rule is that thicker materials generally require larger-diameter wires. However, this is a typical rule of thumb, not a set-in-stone rule.

There is such a thing called current density, understanding this is crucial when welding. for example, it is possible to use 1.4mm ER70s-6 wire on a 1.2mm carbon steel sheet, without any undesirable end results, in fact in many circumstances you can achieve a better weld using the larger diameter wire than the smaller diameter. However, this is on a case-by-case basis and depends on many factors including the shielding gas mix and equipment being used.

There are other factors to consider as well for MIG wire size. Your MIG welding machine's amperage and voltage settings can also play a role in determining the suitable wire size. Check the welding machine's specs for wire sizes recommended based on the amperage and voltage range.

MIG welding wires come in different weights to provide flexibility and convenience for users. Small projects may need only a small amount of wire in 5kg, 15kg, or 18kg reels. Engweld also supplies small MIG wire reels for portable MIG welders and compact welding equipment. Larger industrial projects could require large quantities for which Engweld supplies bulk wire available in 250kg and 500kg.