Welding Rod Numbers Decoded !

Damon Gentile

Typical arc welding rod has a part number like : E6010 or a fancy one is E8018-B1-H4R.

Let's start by decoding the short one. If you have digits left over, it's a long number, read on.

This can be decoded fairly easily.

E stands for "Electrode"

The first two digits (or first 3 if it's a 5-digit number) are an abbreviation of the weld's strength. To figure out the strength of the weld, take the 2 digits, in this case 60, and multiply by 1000 to get the weld strength in PSI.
So if you had welded two plates together, with the weld covering one square inch (or even 1/4" x 4" : that's still one square inch) that weld could take 60,000 pounts of pulling force.
Typical vales are 60,70,80,90,100,110.

The 3rd digit tells you what position the rod is recommended for.
1 : Flat, Horizontal, Vertical, Overhead.
2 : Flat and Horizontal only.
3 : Flat, Horizontal, Vertical Down, Overhead.

The last digit tells you about welding current and the coating.
1 : DC:ROD+ ................... cellulose sodium
2 : AC or DC:ROD+ or DC:ROD- .. cellulose potassium
3 : AC or DC:ROD- ............. titania sodium
4 : AC or DC:ROD- or DC:ROD+ .. iron powder titania
5 : DC:ROD+ ................... low hydrogen sodium
6 : AC or DC:ROD+ ............. low hydrogen potassium
7 : AC or DC:ROD+ or DC:ROD- .. iron powder iron oxide
8 : AC or DC:ROD+ ............. iron powder low hydrogen
You probably don't need to worry much about the coating.
I have in my notes, but don't remeber where I read it, that having the rod + will give deeper penetration, and the rod - will give faster deposition.

If there is a letter and number combination next, it relates to the chemical composition of the weld deposit.

A1                         0.5%Mo
B1              0.5%Cr     0.5%Mo
B2             1.25%Cr     0.5%Mo
B3             2.25%Cr       1%Mo
C1    2.5%Ni
C2   3.25%Ni
C3      1%Ni   0.15%Cr    0.35%Mo
D1                        0.25-0.45%Mo    1.25-2%Mn
D2                        0.25-0.45%Mo    1.25-2%Mn
G*    0.5%Ni   >0.3%Cr   >0.2%Mo                      >0.1%V
* (G only needs one of the elements listed)

Next part is a H#. This relates to the maximum amount of hydrogen that will be diffused from the rod.

A trailing R means that the rod is moisture resistant.