AWS A5.1 Decoded: What E-XXYZ Actually Tells You
Pick up any can of stick electrodes and you will see a code like E7018 or E6011 stamped on the label. It looks cryptic, but it is a compact specification defined by the American Welding Society in AWS A5.1 for carbon steel electrodes. Once you can read it, you can tell at a glance what strength, which positions, and which kind of coating and current you are buying.
What the Letters and Numbers Mean
Every A5.1 classification follows the same pattern: E-XXYZ. Here is how each piece reads:
- E means electrode, a consumable rod used for arc welding.
- XX (the first two digits) give the minimum tensile strength of the deposited weld metal in thousands of pounds per square inch. In E70xx, the 70 means 70,000 psi.
- Y (the third digit) tells you the welding positions the electrode is designed for. A 1 means all positions (flat, horizontal, vertical, overhead). A 2 means flat position and horizontal fillet welds only.
- Y and Z together (the last two digits) describe the flux coating type and the welding current the rod is designed to run on (AC, DCEP, or DCEN).
So E7018 reads as: electrode, 70,000 psi minimum tensile, all positions, low-hydrogen iron-powder coating. And E7024 reads as: electrode, 70,000 psi, flat and horizontal only, iron-powder coating built for high deposition.
Common A5.1 Electrodes at a Glance
| Class | Tensile (min) | Positions | Coating | Current |
|---|---|---|---|---|
| E6010 | 60,000 psi | All | High-cellulose sodium | DCEP |
| E6011 | 60,000 psi | All | High-cellulose potassium | AC or DCEP |
| E6013 | 60,000 psi | All | High-titania potassium (rutile) | AC, DCEP or DCEN |
| E7018 | 70,000 psi | All | Low-hydrogen potassium, iron powder | AC or DCEP |
| E7024 | 70,000 psi | Flat and horizontal fillet | Iron powder, titania | AC, DCEP or DCEN |
What the Code Means for Your Work
- Dirty or rusty steel, pipe root passes: the cellulose-coated 6010 and 6011 rods give a deep, forceful arc. Compare them in our E6010 vs E6011 guide.
- Sheet metal and general-purpose repair: E6013 is soft, easy to strike, and forgiving on AC machines.
- Structural steel and code work: E7018's low-hydrogen coating is the standard choice. Because it is low-hydrogen, it needs to be kept dry; see why hermetically sealed cans matter.
- Heavy flat and horizontal fillets: E7024 deposits fast. Read the E7024 jet rod guide.
Picking the Right Rod
Start with the base metal and the required strength, then check position, then match the coating to your surface condition and your machine's current. If your machine is AC only, make sure the classification lists AC. If the joint is vertical or overhead, avoid classes ending in 2 in the third digit. When a drawing or code calls out a specific class, use that class rather than substituting a similar-looking one.
Buying and Bulk Notes
For active shops, 50 lb hermetically sealed cans are the most economical way to stock the common classes, and the sealed steel can keeps electrodes ready to weld without a rod oven until opened. Smaller 10 lb packages suit occasional users. Buying several cans at once? Contact us about bulk and distributor pricing.
Ready to stock up?
Shop the E7018 50 lb hermetically sealed can, or browse the full mild steel stick electrode collection, including E6011 and E6013.
Frequently Asked Questions
Does the 70 in E7018 mean 70 amps?
No. It is the minimum tensile strength of the weld metal: 70,000 psi. Amperage depends on rod diameter and position, so follow the manufacturer's recommended range for the size you are running.
What does the third digit tell me?
It tells you the positions the rod is designed for. A 1 is all-position; a 2 is flat and horizontal fillet only.
Can I use any E70xx rod where E7018 is specified?
Not automatically. The last two digits change the coating and current, and low-hydrogen E7018 is specified for a reason on structural and high-restraint joints. Check the procedure or drawing first.
What do DCEP and DCEN mean?
DCEP is direct current electrode positive and DCEN is direct current electrode negative. The classification tells you which polarities (or AC) the rod is built to run on.
Safety: Welding produces fumes, arc radiation, sparks and hot metal. Use proper ventilation, a welding helmet with the correct shade, gloves and protective clothing, and follow the electrode manufacturer's instructions and your site's safety procedures.