E6010 vs E7018: Root Pass vs Fill and Cap
These two rods are partners, not competitors. E6010 burns the root pass on pipe, hot, deep, through dirty steel. E7018 fills and caps the joint with a smooth, low-hydrogen deposit that passes X-ray. Most pipe welding procedures call for both.
Side by Side
| Attribute | E6010 | E7018 |
|---|---|---|
| Penetration | Deep, aggressive arc dig | Medium, smooth arc |
| Tensile strength | 60,000 psi | 70,000 psi |
| Slag type | Thin, fast-freeze, negligible coverage | Heavy, self-peeling, full coverage |
| Surface tolerance | Tolerates rust, oil, mill scale, paint | Requires clean, dry, well-prepared joint |
| Storage | Standard dry storage, no reconditioning | Rod oven required (250-300F), moisture sensitive |
| Hydrogen level | High (cellulosic coating generates hydrogen) | Low (H4 or H8 diffusible hydrogen class) |
| Typical application | Pipe root passes, field repairs | Structural steel, pressure vessels, code work |
| Operator skill | Requires significant technique to control | Easier to run with a smooth, forgiving arc |
Use E6010 when:
You need full penetration on an open root joint, are welding in field conditions on imperfect steel, or are doing pipe root passes. E6010 is the go-to root pass rod for pipeline welding.
Use E7018 when:
You need X-ray quality welds meeting structural or pressure vessel code. You are doing fill and cap passes on properly prepared joints. You need high-strength, low-hydrogen deposits with good impact toughness at low temperatures.
How E6010 and E7018 Work Together
On most structural pipe jobs, the procedure (WPS) calls for E6010 on the root and hot pass, then E7018 for the fill and cap. The E6010 burns in deep and creates the fusion. The E7018 builds up the joint with low-hydrogen deposits that will not crack under service loads. Trying to root with E7018 does not work well because it lacks the dig to burn through a root opening. Trying to fill with E6010 is wasteful because the deposition rate is low and the hydrogen content is high.
Common Mistake With E6010
New welders sometimes reach for E7018 for every joint because it is the 'good' rod. But E7018 on dirty, rusty field steel will give you porosity and poor fusion. That is what E6010 is for. Match the rod to the condition of the steel and the stage of the weld, not just the required strength.
Where to Buy
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Data sourced from AWS A5.1/A5.1M.