What Is GMAW? MIG Welding at Universal Technical Institute

UTI Profile Image Universal Technical Institute Jun 27, 2019 ·

GMAW welding, which stands for “gas metal arc” welding and is also known as wire welding, is one of the most common welding processes. In GMAW welding, an electric arc is formed between the metal and a wire electrode, applying heat to the metal pieces. This action melts and fuses the parts together to form a permanent bond..

As we covered in the history of welding, the GMAW welding process emerged in the late 1940s, when a continuously fed electrode wire replaced the tungsten electrode in the gas tungsten arc welding (GTAW) process. It quickly became popular because it was more cost-effective than GTAW. Today, GMAW welding is used in industries ranging from construction and manufacturing to car racing and vehicle production.

One type of GMAW welding is MIG welding. MIG stands for “metal inert gas.” In MIG and GMAW welding, a continuous solid wire electrode travels through the welding gun, along with a shielding gas to shield the process from contaminants in the air, and into the weld pool. This welding process can be used on both thick and thin sheets of metal, as well as aluminum and other non-ferrous materials.

GMAW welding is used indoors and is not suitable for outdoor projects. Outdoor elements like wind can blow the shielding gas away from the weld pool and cause defective joints. Indoors, away from the elements, GMAW welding is one of the most productive, low-cost welding processes. There's minimal clean-up and minimal waste, and the process is not prone to chipping.

Why Use GMAW Welding?

GMAW welding has many applications in some of the world's biggest industries. GMAW welding may be used for:

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

There are several ways to perform GMAW welding: manual, semi-automatic or automatic. The technique you use will determine the tools you need, including a hand-held, robotic or machine-controlled welding gun. A semi-automatic GMAW process will require a power source, a welding gun, wire feeders that ensure constant voltage and speed, a supply of electrode wire and a shielding gas cylinder.

One of the advantages to GMAW welding is that it can be done in all positions. By using a continuously-fed electrode, there's less occurrence of defects on stops and starts. Because much of the GMAW process is automated, it's a simple process for the welder to perform, since the welder doesn't have to worry about maintaining a precise arc length.

To be successful, GMAW welders must master how to properly guide and clean the gun and optimize the voltage, flow rate and wire feed rate. The travel speed a welder employs will influence the quality and shape of the weld. GMAW welders need to judge how the weld puddle size relates to the joint thickness in order to determine the correct travel speed.

And, like all welding jobs, proper protective clothing and safety materials must be worn to keep the welder safe.

What GMAW Welding Techniques Does UTI Teach?

At Universal Technical Institute's (UTI) welding program, students learn how to master GMAW techniques, equipment and applications, in courses such as Gas Metal Arc Welding I and II and Welding Applications. Students learn skills like:

  • How to set up and use GMAW equipment and the required welding accessories
  • Modes of metal transfer
  • Different gases available to shield a weld
  • How to produce groove style joints and steel fillet in the horizontal and flat planes
  • Basic maintenance of a GMAW-style welder, including gas hook-up and wire spool replacement
  • How to perform overhead and vertical welds
  • How to change out whips/guns, correctly maintain a GMAW welder, set up different shielding gas and replace rollers
  • How to build specific projects and perform various weld types in all positions

UTI students are also taught welding safety, blueprint basics and mathematics used in fabrication. Brian Masumoto, a welding instructor at UTI Rancho Cucamonga, says the main advantage of UTI's program is the breadth of instructor experience.

“Our instructors have 70+ years of experience in welding and fabrication,” says Masumoto. “As instructors, we find out what type of welding career the students want to get into and apply what's in the curriculum to that specific job.”

Learn more about the welding programs offered at UTI, and get welding training information online.

Classes start soon. With classes starting every 3-6 weeks, no need to wait to start your career.
Hands-on training. Get hands on experience with the industry's leading brands.
No Pressure to commit. Get answers to your questions without any obligations
Call Now 800.834.7308 Or request more info
Training For A New Career Starts Here

It only takes a few minutes to learn about technician training opportunities.

Please enter your email address

By submitting this form, I agree that Universal Technical Institute, Inc., Custom Training Group, Inc., and their representatives may email, call, and / or text me with marketing messages about educational programs and services, as well as for school - related communications, at any phone number I provide, including a wireless number, using prerecorded calls or automated technology. I understand that my consent is not required to apply, enroll or make any purchase.

By submitting this form, I further understand and agree that all information provided is subject to UTI’s Privacy Policy available at

Motorcycle Mechanics Institute
Marine Mechanics Institute
NASCAR Technical Institute