Welding with Greggs: FCAW AWS Classes

For the last blog in this Welding series let’s break down the AWS codes for FCAW and see what we’ll find!

Understanding FCAW Codes

FCAW stands for Flux Cored Arc Welding. This process also uses a tubular wire, but instead of a metal powder, the wire is filled with a material called “Flux”. Here are some examples of FCAW Codes:

E71T-9C

Our first example code will be “E71T-9C” (E-7-1-T-9-C)

E - “E”, as always, stands for Electrode
7 - “7” stands for the tensile strength just like before, but is reduced by 1 digit. So, a “7” here is the same as a “70” in the other codes, standing for 70,000 pounds per square inch
1 - “1” stands for the welding position and can either be a “1”, which means all positions, or a “0” which means only Flat and Horizontal welding
T - “T” stands for “Tubular Wire, meaning the wire is hollow, containing flux.
9 - “9” indicates the polarity and whether it is usable for single or multiple passes. It can be a number from 1 to 14, a G, or a GS, and you can find what the numbers represent in a lookup table. This designator can appear before or after a hyphen in the code
C - “C”, just like before, tells us what gas we need, and can be a “C” or an “M”.

Welding with Greggs: FCAW AWS Classes | Gear Up With Gregg's Blog

Much like the other 2 types of classes, there are some designators that can appear after the code.

A letter, typically followed by a number, is used for Low-Alloy products, and designates the composition of the resulting weld metal. (e.g.E71TG-G)
“J” represents that the product has improved toughness. If it does not have this characteristic, the J will not be present. (e.g. E71T-9C-J)
“D” will indicate that the weld metal will meet certain requirements when using temperature specific procedures. This can be represented by either a “D” or a “Q” (e.g. E71T-9C-D)
Finally, “H” followed by a number, like before, states the hydrogen content of the product. (e.g. E71T-9C H4)

Let’s read a few codes for FCAW.

E70T-6

E means that this is an electrode. The 7 tells us that this product has 70ksi of tensile strength. The “0” means this can only be welded in the flat and horizontal positions. The “T” tells us this is a tubular wire, and the “6” informs us that the required polarity is DC Electrode Positive and it will be good for multiple passes.

E71TG-G

It’s an electrode, has 70ksi tensile strength, can be welded in all positions, is a tubular wire, has no specified polarity and is good for multiple passes, and the weld metal will be a Low-Alloy Steel composition.

E71T-12M-JH4

It’s an electrode, has 70ksi tensile strength, can weld in all positions, is a tubular wire, needs a DC Electrode Positive current and is good for multiple passes, needs an Argon and CO2 gas blend, has improved toughness, and has less than 4ml of hydrogen per 100g.

And there you have it! We now know how to read all of the primary AWS classes you’ll encounter on a day to day basis. Something to keep in mind is that most people do not know all of these breakdowns by heart, so don’t be afraid to use the resources we have made available to figure out what your filler metal is! Most of the time, if it is for a specific process, the product needed will already be stated for you, so you won’t have to figure it out on your own.

One last thing worth mentioning is that when you get into the products specified for Stainless Steel, Nickel, and Aluminium, the AWS classes for each metal type have their own parameters. If you’re needing help with those products, or anything else for your welding needs, like a shiny new helmet, some gloves, an apron or, hey, how about a fancy new multi-process welder, then give us a call, or come on down to the counter, and we’ll be sure to get you up and running. 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. Have a great Canadian Day!