What’s Wrong with MIG and TIG?

August 2023
By: Eric Lichtfusz

AWS Certified Welding Inspectors (CWIs), especially those who travel to different job sites and shops, are often inundated with slang terminology and nonstandard terms for welds, welders, power sources, welding equipment, and many others. We’ve all heard terms such as buzz box, stinger, heliarc, weld puddle, whip, bubble gum weld, and so on. Two of the most recognized examples are the acronyms MIG (metal inert gas) and TIG (tungsten inert gas), which are nonstandard terms for gas metal arc welding (GMAW) and gas tungsten arc welding (GTAW), respectively. Many consider MIG or TIG as just names for particular welding processes without realizing they are acronyms. Surprisingly, a Google search for “what is MIG welding” points to various websites explaining almost everything about the MIG welding process except, in most instances, what the letters mean.

My question is, what type of metal are you welding with so-called MIG welding using an inert gas? MIG may be appropriate in some instances, but if you’re welding ferrous and using some argon/carbon dioxide gas blend for shielding, the gas is not classified as inert. It’s an active gas. This makes the acronym MIG incorrect or, at the very least, technically inaccurate.

As an AWS CWI, why do I care? I care because I’ve been certified and trained by AWS to be an expert and apply terminology accurately. AWS defines MIG welding as a nonstandard term for GMAW. The 2020 edition of AWS A3.0M/A3.0, Standard Welding Terms and Definitions, explains in its foreword the Society’s position on nonstandard terms: “It must be understood that the Definitions Subcommittee cannot be the ultimate judge in terms of the preferability, acceptability, or correctness of any term for a specific situation. Such determinations are left to the discretion and opinion of the welding terminology user. There is one exception: when using a nonstandard term may endanger personal safety, that term is defined as both nonstandard and incorrect. The Definitions Subcommittee has neither the authority nor the desire to dictate welding terminology but considers it within its province to establish standard terms and nonstandard terms.” 

The definition for TIG is more accurate than the one for MIG; however, the AWS A3 standard defines TIG as “a nonstandard term for gas tungsten arc welding.” 

Another example is shielded metal arc welding (SMAW). SMAW is known to many as stick welding or stick electrode welding; both are also considered nonstandard terms by AWS. For example, what kind of stick do you use with this process, and what do you do with this stick?

Many other terms may be familiar to many and considered nonstandard to AWS, but instead of a short editorial, I would need to write a book to cover all of them. Fortunately, AWS A3.0 (available through the AWS bookstore at pubs.aws.org) includes more than 1500 terms with numerous illustrations to support and clarify definitions. I highly suggest you get familiar with it. You’ll be a better CWI for it, and your clients will thank you, too.  

Eric Lichtfusz (eric.lichtfusz@roush.com) is a CWI-manager at Roush Industries, Livonia, Mich. He is also an AWS Detroit Section executive committee senior past chair and ASNT Level II inspector.