MIG Welding Stainless Steel

You can weld stainless steel with the MIG welding process. MIG (Metal Inert Gas) welding, also known as Gas Metal Arc Welding (GMAW), is a type of welding process in which a continuous solid wire electrode is heated and fed through a welding torch into the weld pool. The arc melts the two metals together and forms a joint. One advantage of MIG welding process over others is that you can use pulsed current supply which allows you to weld in hard to reach areas.

Generally, MIG welding is the preferred option for applications involving long welds requiring speed and efficiency. TIG welding is preferred for applications requiring precision for clean controlled welds and aesthetics. If the application involves long joints in relatively thick material or a large number of parts then MIG welding is the right choice as it offers efficiency and cost effective welding.

When choosing to MIG weld stainless steel there are certain factors that need to be taken into consideration.

Welding machine

You can weld stainless steel with a MIG Welders and they typically have an inbuilt wire feeder to continuously feed filler wire through the welding torch. You won’t have to constantly change electrodes or filler rods as you would with TIG welding. Make sure the welding machine has sufficient power output to handle the thickness of stainless steel you will be working on.

The settings such as voltage and amperage on your welding machine will vary depending on the application for example, wire diameter, shielding gas, material thickness, weld size etc. It may be best to start with the settings recommended by the mig welding wire manufacturer. It's important to choose the right MIG Welder for you project.

MIG Torch

MIG Welding machines usually come with a MIG torch. Make sure the components of the torch are designed to work with stainless steel. For example, for stainless steel welding it is important to use a liner made of a non-reactive material such as Nylon or Teflon, to prevent contamination of the wire and to ensure smooth wire feed.

It is recommended that you use a separate set of drive rolls and liners for stainless steel to prevent cross contamination. If you don’t have separate ones then you must clean them with a solvent that doesn’t leave any residue before using them for welding stainless steel.

Filler wire

Use appropriate mig welding wire with the right diameter for your application to match the grade of stainless steel being welding. Common mig wires include ER308, ER309, and ER316.

Shielding Gas

You must choose the right shielding for stainless steel to prevent contamination. A popular choice for mig welding stainless steel is a mix of Helium, Argon, and Carbon Dioxide. The tri-mix provides the optimal weldability and weld quality. Use the gas selector tool or download the gas selector guide to choose the right gas for your welding application.

Welding parameters

Use the right settings for welding stainless steel on your MIG welding machine, including voltage, wire feed speed, and travel speed to achieve the desired weld quality and penetration.

Welding technique

Should be based on the thickness of the stainless steel and the specific joint design. Use the push technique which allows you to see more clearly what you are doing. Use the pull technique if the application requires deeper penetration.

Related articles about MIG Welders

• TIG Welding Stainless Steel
• An overview of aluminium MIG welding
• How To Maintain Your MIG Welder