Basic Guide Of How To MIG Welding Stainless Steel

MIG welding is a famous welding process almost all factories and industries use today. Also known as gas metal arc welding, it is a good welding method since it can weld any metal parts. It is known among welders throughout the world for a long time.

Meanwhile, stainless steel welding is a fun project if you know the hang of it. Even though it is a bit complex, welding stainless steel, you can have precise results. It is imperative to understand the welding process of stainless steel using different welding methods. Although, if you can weld carbon steel, we should mention that the process is similar to welding stainless steel.

Today, we will describe how you can join stainless steel parts using MIG welding.

Information on Stainless Steel

Created in 1913, stainless steel is a metal allow of iron. It is mixed with many different types of material to increase its heat-resistance. Among them, it should at least have 11% chromium. Thanks to chromium, the alloy does not corrode or rust. However, this heat and rust-resistance can further be increase by increasing the amount of chromium or molybdenum.

All these traits make stainless steel perfectly suitable for various applications where high heat or water is involved. Before you go for MIG welding stainless steel, you got to know the different variations of it. There are apparently five types of stainless steel, depending on the amount of chromium and other elements.

Austenitic Stainless Steel

Austenitic stainless steel is the most common stainless-steel variation. They are the most capable stainless steel among all. Taking up 70% of the industrial stainless-steel production, they contain 18% chromium and 8% nickel at the minimum. This feature makes them more thermally resistant than other stainless steel. The prime type of these stainless steel is surgical stainless steel that contains 20% chromium with 10% nickel. They are capable of being work-hardened.

Martensitic Stainless Steel

A different type of stainless steel that is so weak and brittle. They are only suitable to be used on any application that wears down easily. Apparently, it is literally the first stainless steel that was found. They can be hardened for usage. The amazing thing about them is that you can change them to austenitic stainless steel.

Ferritic Stainless Steel

When it comes to vehicle exhaust systems, nothing beats ferritic stainless steel. Having 17% chromium, they are hard to harden but highly ductile. They are also much affordable compared to all other stainless steel.

Precipitation Hardening Steel

Like how its name sounds, these special stainless steels are so easy to harden and weld. They are stainless steels that are changed to make them more convenient to use.

Duplex Stainless Steel

They are the stainless-steel alloys made from a mixture of austenitic and ferritic steel. They are highly tougher than any other stainless steel variation.

Now, let’s get to the welding process-


Before everything, there are some preparations you need to undergo for the welding.

  • Clean Up the welding machine and stainless steel properly using clean cloths.
  • Take a suitable filler material. Without the right filler metal, the welding will not be proper. Match the grade of the stainless steel and the filler metal.
  • Set-up the MIG welding machine properly. Make sure that the ground clamp is of high quality.
  • Check the thickness and type of the stainless steel you will weld.

MIG Welding Set-Up

To be honest, the set-up for MIG welding is the easiest among many different welding processes. If you check your MIG welding machine, you will see a chart that explains the required size and feed rate of the welding rods, gases, amp ratings, etc., depending on different thickness of metals. All you need to do is to set the machine following the chart. A MIG weld set-up looks like this-

MIG Welding Set Up

Be sure to pick the correct gas and electrode types for the right stainless-steel thickness.

Welding Process

After you have set-up everything, you must set the correct voltage supply for the electrode. In MIG welding, the voltage will remain unchanged. But the heat and current changes depending on the arc length. Small arcs provide much current flows and heat output. So, if you want to weld thick stainless steel, weld it with small arcs.

You can use DCEP or AC connection for the welding hook-up. The gas flow rate of the machine must be correct. While welding, stay careful that the stickout (distance between the arc and nozzle tip) is below 0.5 inches.

Final Note

As you are welding, you should be careful not to overheat the stainless steel. Stainless steel is a valuable material. It is the reason why many novices feel uncomfortable while welding it, even though it is pretty simple. With some tries, it will not take time for you to master this skill.

Last Updated on 1 year by Richard Boyer

  • June 8, 2022
Richard Boyer

Richard Boyer has been a professional welder for over 27 years of his life, and now he is a trainer and blogger providing critical information to anyone interested in welding. He is helping out both hobbyists, novice and professional welders to learn newer and better techniques. Read more about me

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