Welding with Greggs: GTAW or GMAW AWS Classes

Even though GTAW and GMAW are different welding processes, they both share the same formula for their AWS classes. Let’s get into what makes them share the same formula!

Interpreting GTAW and GMAW Welding Codes

GTAW stands for Gas Tungsten Arc Welding, or also called as TIG Welding in the industry while GMAW stands for Gas Metal Arc Welding, and is commonly called MIG Welding. Here are some examples:

ER70S (E -R-70-S)

Our example code this time will be “ER70S”

“E” - stands for electrode wire
“R” - stands for “Rod” which means it is a GTAW cut length, or that it is a GMAW wire that can be repurposed as a cut length for GTAW. If there is no “R” next to the “E”, it can only be used as a GMAW wire.
“70” - just like in Stick, stands for the tensile strength in Kilopounds per Square Inch
“S” - Finally, the letter at the end of the code indicates the type of wire, and can either be an “S” for Solid Wire, or a “C” meaning it’s a metal cored wire for GMAW-C.

Welding with Greggs: GTAW or GMAW AWS Classes | Gear Up With Gregg's Blog

Like Welding Stick Code, there can be additional designators added after the initial code.

First is the average chemical composition of the product, and this can be represented as either a 2, 3, 4, 6, 7.
You may also see a letter followed by a number that states the chemical composition of the resulting weld metal. For example, “Ni” followed by a number means the weld metal is a Nickle Steel composition.
Next is the required shielding gas mixture, which can either be a “C”, for 100% CO2, or an “M”, for a mixture of CO2 and Argon.
If an “N” is shown, this simply means that the product is rated for nuclear applications (Eg. ER90S N)
Finally, the Hydrogen Code, which is exactly like Stick, where it represents the hydrogen content per 100 grams. (Eg. E70C H4)

Let’s read a few codes to make sure we understand!

ER80S-Ni1

We know this product is an Electrode/Rod because of the ER designators. The 80 tells us it has 80ksi of tensile strength. The S indicates that this product is solid wire, and Ni1 lets us know that the weld metal will have a Nickel-Steel composition.

ER100S-G

It’s an Electrode/Rod, has 100ksi tensile strength, is a solid wire product, and has an unspecified composition that is good for multiple passes.

E70C-6 M H4

It’s an Electrode Wire only, has 70ksi tensile strength, is a metal cored product, has a specified chemical composition, needs an Argon and CO2 gas blend, and has less than 4ml of hydrogen per 100g.

Alright, I think that’s enough information for now. On the blog, we will cover the Flux Cored Arc Welding! If you have any further questions, visit our website at greggdistributors.ca. And while you’re still here why not subscribe to our YouTube channel!