Which Welding Rod for Structural Steel
Top pick: E7018, starting at 70-100A on DCEP/AC. 5 rods compared with settings for this application.
Structural steel welding is governed by codes, primarily AWS D1.1 Structural Welding Code for buildings and AWS D1.5 Bridge Welding Code. The filler metal must meet the strength, toughness, and hydrogen requirements specified by the engineer. This is not a choose-what-you-prefer situation. The WPS dictates the filler.
Best Rods for Structural Steel
E7018
The standard structural steel stick electrode. Low-hydrogen iron powder coating, 70 ksi tensile, smooth drag technique. Required by most structural WPS documents. Must be stored in a rod oven.
E7018-1
Required when the WPS specifies impact testing at -20F. Identical to E7018 in operation. Mandatory for seismic applications (AWS D1.8) and cold-climate structural work.
E71T-1
Gas-shielded flux-core for shop fabrication. Higher deposition rate than E7018 for production welding. Requires 75/25 Ar/CO2 or CO2 gas. Common in structural steel fabrication shops.
E71T-8
Self-shielded flux-core for field erection. No gas required, works in wind. Seismic-rated for AWS D1.8. The standard wire for structural steel erection at height in the field.
ER70S-6
MIG wire for structural welding in the shop. Used for lighter structural members, miscellaneous steel, and connections where flux-core is overkill.
Quick Amperage Reference for Structural Steel
| Electrode | Polarity | Common Size | Amps | Full Chart |
|---|---|---|---|---|
| E7018 | DCEP / AC | 1/8" | 90-160A | E7018 chart |
| E7018-1 | AC / DCEP | 1/8" | 100-160A | E7018-1 chart |
| E71T-1 | DCEP | .045" | 150-300A | E71T-1 chart |
| E71T-8 | DCEN | 0.045" | 130-230A | E71T-8 chart |
| ER70S-6 | DCEP | 0.035" | 50-220A | ER70S-6 chart |
Structural Welding Technique
Structural welding demands verified technique. Welders must be qualified to AWS D1.1 for the specific joint, position, and thickness range. Preheat requirements depend on the base metal grade, thickness, and ambient temperature. Interpass temperature maximums apply. Electrode storage and exposure time limits are code requirements, not suggestions.
For E7018, maintain a tight arc with consistent travel speed. The drag technique (pulling the rod) is standard. Listen for a consistent frying sound. If the arc sounds irregular, check your settings and arc length.
Which Rod for Your Situation
Equipment You Need
Structural welding machines start at 300A for production work. A rod oven holding 250-300F is mandatory for E7018 on code jobs. Field erection rigs run E71T-8 on wire feeders mounted to structural steel with magnets. The welder qualification test is a prerequisite. You cannot touch structural steel without passing the position test.
Mistakes to Avoid With Structural Steel
Using non-low-hydrogen electrodes (E6013, E6011) for structural connections that require E7018. This is a code violation regardless of how the weld looks. Using E7018 that has been exposed to atmosphere beyond the allowed time limit. Welding in positions or on thicknesses outside your qualification range. Skipping preheat in cold weather.
What Goes Wrong
A non-certified welder used E6013 on a moment connection in a steel-frame building. The building inspector rejected the entire connection. E6013 is not a low-hydrogen electrode and is not listed on any structural WPS. The connection was gouged out and rewelded with E7018 by a qualified welder. The rework cost more than the original fabrication.
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Reference data only. Verify all settings against manufacturer documentation and the applicable welding code before use. Amperage ranges are starting points that vary by position, fit-up, and material. Welding involves serious injury risks including burns, electric shock, fume exposure, and fire. This site does not replace proper training, certification, or employer safety procedures. See full terms of use.