AWS A5.1/A5.1M · Carbon & Mild Steel
E7018 Welding Electrode
E7018 is the low-hydrogen structural rod — 70 ksi tensile, tough at -20 °F, all positions, and the default electrode on most structural and code work.
- 70 ksi tensile
- Polarity DCEP, AC
- 4 positions
- Medium penetration
- Stick (SMAW)
What E7018 means
| Part | Meaning |
|---|---|
| E | Electrode for shielded metal arc welding |
| 70 | 70,000 psi minimum tensile strength |
| 1 | All welding positions |
| 8 | Low-hydrogen potassium coating with iron powder, AC or DCEP |
E7018 specifications
| AWS specification | AWS A5.1/A5.1M |
|---|---|
| Process | Stick (SMAW) |
| Form | Covered electrode |
| Polarity | DCEP, AC |
| Welding positions | Flat, Horizontal, Vertical, Overhead |
| Tensile strength (min) | 70 ksi (483 MPa) |
| Yield strength (min) | 58 ksi (400 MPa) |
| Elongation (min) | 22% |
| Impact toughness | 20 ft·lb at -20 °F (27 J at -29 °C) |
| Coating / core | Low-hydrogen potassium with iron powder |
| Penetration | Medium |
| Deposition rate | High |
| Slag | Heavy, brown-glassy, releases cleanly when run correctly |
| Arc character | Smooth and quiet with a fluid puddle |
| Shielding gas | None — self-shielding |
E7018 amperage by diameter
Typical operating ranges. Start near the middle of the range, then adjust by sound and bead profile. Reduce 10–15% for vertical and overhead work.
| Diameter | Amperage range | Typical start |
|---|---|---|
| 3/32 in (2.4 mm) | 70–120 A | 95 A |
| 1/8 in (3.2 mm) | 110–165 A | 138 A |
| 5/32 in (4.0 mm) | 150–220 A | 185 A |
| 3/16 in (4.8 mm) | 200–275 A | 238 A |
| 7/32 in (5.6 mm) | 260–340 A | 300 A |
Polarity: DCEP is standard and gives the best arc stability. AC is permitted by the classification and is used on transformer machines, though the arc is softer and starts are harder.
What E7018 is used for
- Structural steel erection, bridges and buildings
- Pressure vessel and piping fill and cap passes
- Heavy equipment and machinery fabrication
- Any joint where low diffusible hydrogen is required to avoid cold cracking
- Welding on thick sections or restrained joints
Base metals
- A36 and A572 structural steel
- A516 pressure vessel plate
- Medium-carbon steel
- Heavy plate and structural shapes
Characteristics
- Low diffusible hydrogen deposit — the reason it resists underbead and cold cracking
- Excellent notch toughness down to -20 °F (-29 °C)
- Smooth, flat-faced beads with good wetting at the toes
- Iron powder in the coating raises deposition above E7016
- Coating absorbs atmospheric moisture quickly, which is why storage discipline matters
Storage and handling
Low-hydrogen rods must be kept dry. Hermetically sealed until opened, then held in a rod oven at 250–300 °F (120–150 °C).
- Store unopened containers at 65 °F (18 °C) or above with relative humidity under 50%.
- After opening, hold electrodes in a heated rod oven at 250–300 °F (120–150 °C).
- Exposure limits on code work are typically 4 hours for standard E7018 and 9 hours for the H4R moisture-resistant grades — always follow the governing code and the manufacturer's data sheet.
- Rods exposed beyond the limit can usually be reconditioned once by baking at 500–800 °F (260–430 °C) for one to two hours.
- Never recondition an electrode twice, and never use a rod with a cracked or swollen coating.
Welding tips
- Strike ahead of the joint and drag back into the puddle — E7018 tips are prone to sticking on a cold start.
- Keep a tight arc, about one electrode diameter, and let the slag trail the puddle.
- On 1/4 in plate fillets, a 1/8 in rod at 125–140 A DCEP is the everyday setting.
- Vertical-up: reduce amperage 10–15% from flat and use a slight side-to-side motion with a pause at each toe.
- If you see wagon-track porosity along the toes, the rod has picked up moisture.
E7018 frequently asked questions
What amperage for 1/8 in E7018?
110–165 A DCEP. Most shop work on 1/4 in plate runs 125–140 A flat, dropping to about 115–125 A for vertical-up.
Why does E7018 need a rod oven?
Its low-hydrogen coating absorbs moisture from the air. That moisture becomes diffusible hydrogen in the weld, which causes delayed cold cracking in the heat-affected zone. Holding the rods at 250–300 °F keeps the coating dry.
Can E7018 run on AC?
Yes. The 8 in the classification covers AC and DCEP. DCEP gives a more stable arc and easier starts, but E7018 is routinely run on AC transformer machines.
Can you weld vertical-down with E7018?
Not on code work. The heavy slag runs ahead of the puddle going downhill and causes slag inclusions and lack of fusion. E7018 is run vertical-up.
How long can E7018 stay out of the oven?
Typically 4 hours for standard E7018 and up to 9 hours for H4R moisture-resistant grades, but the governing code and the manufacturer's data sheet set the actual limit.
What is the difference between E7018 and E7018-1?
E7018-1 meets a lower-temperature impact requirement, 20 ft·lb at -50 °F instead of -20 °F, and has a slightly higher minimum elongation. Chemistry and handling are otherwise the same.
Compare E7018 with
- E6010 vs E7018
- E6013 vs E7018
- E7014 vs E7018
- E7018 vs E7024
- E6011 vs E7018
- ER70S-6 vs E7018
- E7018 vs E71T-1
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