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GMAW Welding – A Complete detail Guide

If you’re into the industrial welding domain, you would have heard about the GMAW. If you haven’t and want to know, read along. GMAW is also known as gas metal arc welding, commonly used in industries because of its quick and effective nature.

How does GMAW work? Why is it preferred over other welding techniques? Well, you can find all of your answers regarding GMAW below. So, let’s start.

What is GMAW

Earlier construction and manufacturing industries had to invest a lot in building materials and human labor. The obsolete or traditional methods consumed up to 85% of the total costs. And this is what led to the use of GMAW.

GMAW, also known as gas metal arc welding or wire welding, is an effective welding process. An electric arc appears between the wire electrode and metal by the application of heat. This melts the metal and fuses the parts permanently. Now, GMAW is very effective as it can reduce labor costs by up to 25%. It is the reason why industries are opting for this welding approach.

How Does GMAW Work?

Now, GMAW is a vast term. Any welding process which uses gas for welding can be categorized under the GMAW. So, MIG, which is known as Metal Inert Gas welding, also comes under this category. Let’s understand how it works:

During a MIG welding process, there’s a work price and a wire electrode that is used. The process takes place when an electric arc is formed between the workpiece and the wire electrode. Now, the temperature rises, which melts both the workpiece and wire electrode.

The electrode continuously gets its supply during the process. Also, a shielding gas is used in this process. Now, as we’re talking about MIG welding, the gases used in this are inter gases like helium or argon.

Is GMAW or MIG Automatic or Manual?

The MIG welding process is semi-automatic. It’s because the power controls arc length and wire feed. But you need to manually control the speed and position.

How to Ensure Successful MIG Welding

To ensure a successful welding process, welders should learn how to: –

  • Optimize the Voltage
  • Control the flow rate and wire-feed
  • Clean the Gun

Another important thing a welder should know about is the travel speed. After all, it’ll control the shape and quality of the weld.


GMAW equipment usually consists of a

  • Power supply
  • A shielding gas supply system
  • Wire Drive system for pulling the wire electrode from the spool
  • Source of cool water for cooling the welding gun

When the wire is passed through the gun, it becomes energized on getting in contact by a copper contact tube. It transfers the current from the source of power to the arc. There’s an accurate system of controls which: –

  • Initiates and terminates the shielding gas and cooling water
  • Operates the welding contractor
  • Controls the electrode feed speed according to the requirements

Gas Used for GMAW

GMAW or Gas Metal Arc Welding, as the name says, uses gases for the process. The gases prevent the contaminants from entering the weld pool. Commonly used gases for GMAW are Argon and Helium. Such gases are inert or inactive, which means they won’t react with the workpiece.

Power Sources

Most semi-automatic and MIG welding processes require a constant voltage power supply. It’s the power source that delivers constant voltage to the electric arc during the entire procedure. You can also find a self-correcting arc length, which helps in producing better welding conditions.

Tools Used

Common tools used during the GMAW of the MIG welding process are: –

  • Pliers
  • Welding magnets
  • MIG welding machine
  • Chop saw
  • Angle grinder
  • Band saw
  • Soapstone
  • Chipping hammer
  • Clamps

There are several safety equipment like gloves, protective clothing, and auto-darkening helpmeets for added protection.

What Is GMAW Used For?

Here are some common applications of GMAW welding: –

  • Aerospace
  • Automotive maintenance and production
  • Manufacturing
  • Pipe welding/pipe joints
  • Construction
  • Custom fabrication
  • Shipbuilding
  • Underwater welding
  • Railroad track repair and construction

It’s the versatile nature of GMAW welding methods that make it a preferred choice for industry workers. You can use it in small repair shops as well as in large industrial settings.

Advantages of GMAW Welding

Let’s now talk about the advantages of the GMAW welding process: –

Easy to Master

While the GMAW requires you to be a master of this process, it’s very easy to learn. As it’s a one-hand operation, anyone with basic knowledge can get the job.

Highly Versatile

Unlike other welding methods, you can use MIG or GMAW welding for numerous alloys and metals. You can also find a good range of filler electrode materials, which further increase the range of welds.

Easy to Clean

The GMAW welding process involves the use of a shielding gas during the welding process. It protects the arc and minimizes the slag and spatter produced. So, you won’t have to put in much effort in cleaning the job site or the machine.

Simple Controls

Depending on the machine you buy, you can find numerous settings to tweak the polarity, amperage, and wire speed. So, it offers numerous options to make it easy to use.


It is one of the benefits that motivate industries to use the GMAW welding method. It’s very easy to clean and offers a one-handed operation, making it easy to control and handle. Its ease of handling helps in completing the jobs more quickly, easily, and effectively.

Disadvantages of GMAW Welding

GMAW or MIG welding has some good advantages, but it has some disadvantages too. Here are some of them: –

Not Cost-Effective

The MIG or GMAW welding machine is costly. So, you need to spend good money upfront if you want to use this equipment. On top of it, this machine requires maintenance and regular replacement of parts for better efficiency.

Limited to Indoor Use

Another downside of MIG welding machines is that they’re not portable. You cannot carry it around. It uses shielding gases that can be blown away by the wind outside. And without stable shielding, you cannot protect the arc, which further affects the process. It’s the reason GMAW is performed only in indoor settings.

Chances of Burn Through

Burn through is a process that burns the metal if it’s less than the specified width. And this is what happens with MIG welding. All the materials below 0.5mm thickness tend to melt in this process. So, you’ll be limited to the use of a specified set of metals.

Welding positions are limited.

When it comes to welding using the GMAW technique, especially the MIG, the welding positions are limited. It comes with fluidity and high heat input, so you might face difficulty in overhead or vertical welding.


The GMAW welding process is one of the latest and most effective welding processes. It involves the use of shielding gas and a metal arc and offers a strong and permanent bond in the end. However, it’s a process for the experts. So, not anyone can perform it perfectly.

It is most commonly used in industries because of the effectiveness & reduced labor charges. So, if you want to use it, make sure to learn well.

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