Mercifully, the AWS standard for carbon steel flux-cored wire (AWS A5.20) varies only slightly from the MIG solid wire code.

Instead of ER, an E (for electrode) begins the number in the case of all flux-cored wire.

And instead of an S for solid wire, you’ll see either a T for tubular, or C, indicating a “composite” wire. 

E70C-6 is an example of a general-purpose flux-cored wire.

The number 7 in the classification refers to tensile strength, multiplied by 10,000 (instead of 1,000 in the case of a non-cored MIG wire).

0 indicates the welding position. (A zero means the wire is only good for horizontal or flat welding.)

One of the most frequently used flux-cored wires in building construction is Lincoln Electric’s Innershield 232, (aka NR-232), which conforms to AWS E71T-8.

The digit 1 indicates the wire can be used in all positions. The 8 signifies low hydrogen, which calls to mind the common stick electrode E7018. 

NR-232 is popular because its chemical composition meets seismic requirements for earthquake zones like California. On the downside, the wire is more difficult to work with than wires that don’t have the same level of seismic toughness.

The chart below lists recommended parameters for NR-232 (“NR” said aloud sounds like “inner”, which makes it easy to remember.)