ER100S-G is a MIG/GMAW filler metal family used on high-strength low-alloy steel applications where the weld procedure calls for higher-strength filler selection. Treat the classification as a starting point, not a final approval. Before ordering wire or striking an arc, verify the WPS, the code requirement, the base metal grade, the service conditions, and the manufacturer data sheet. If any of those inputs are unclear, the correct answer is not to assume. The correct answer is to verify.
Key Takeaways
- ER100S-G is an AWS A5.28 classification for MIG/GMAW wire used in higher-strength low-alloy applications.
- The “G” classification means general composition is not fully fixed by the classification alone. Verify the manufacturer data sheet before use.
- Do not select this wire only by strength number. Match the weld metal to the WPS, base metal, and service conditions.
- Use the filler metal finder page as a selection starting point, not as proof that a wire is procedure-approved for your job.
- Wire diameter, shielding gas, and parameter set are Unknown (Verify) unless confirmed on the datasheet and WPS.
What ER100S-G Means in Practice
For maintenance buyers and fabricators, ER100S-G usually comes up when the application needs a higher-strength weld metal than common mild steel wire choices. It is associated with HSLA steel work, but that does not mean it fits every HSLA job. The designation alone does not tell you the complete chemistry, toughness level, or procedure limits. Those details are controlled by the specific product datasheet and the approved welding procedure.
When reviewing a job package, start with the base metal specification and the service environment. Then check whether the WPS calls for ER100S-G or allows an equivalent filler. If the WPS is missing, stop and verify it before purchase. If the code requirement is unclear, stop and verify that too.
Filler Metal Finder Section
Weld Support Parts lists ER100S-G here as a selection aid:
ER100S-G MIG / GMAW Filler Metal
Use the filler metal finder page to compare categories and narrow down options:
These pages help with identification and shortlisting. They do not replace the WPS, code review, or manufacturer documentation. They do not guarantee procedure approval.
Check, Inspect, Verify Before Ordering
Check: Confirm the base metal grade, joint design, process, and any code constraints. If the job uses impact toughness requirements, crack-sensitive service, or postweld heat treatment limits, verify those details first.
Inspect: Review the existing wire, spool label, and job paperwork. Look for the classification, lot identification, and any supporting documentation. If the label is incomplete, treat it as Unknown (Verify).
Verify: Confirm diameter, shielding gas, and operating range on the manufacturer data sheet. If the datasheet is not available, do not assume .035 in, .045 in, or any other size is available for the job. Verify all consumable details before issuing to production.
Troubleshooting and Support Notes
If weld quality is not meeting expectations, separate the filler-metal question from the machine-settings question.
- Check the WPS first. If the procedure does not call for ER100S-G, do not substitute without approval.
- Inspect the wire condition. Look for rust, contamination, birdnesting damage, or storage exposure.
- Verify shielding gas and flow. Gas type and flow rate are application-dependent and Unknown (Verify) unless specified by the WPS and datasheet.
- Verify drive roll and liner setup. Poor feeding can look like a metallurgy issue when it is actually a delivery issue.
- Check base-metal cleanliness. Mill scale, oil, moisture, and paint can drive porosity and lack of fusion.
If the weld is cracking, do not keep increasing heat or changing wire blindly. Verify hydrogen control, restraint, joint prep, interpass temperature, and whether the selected filler is appropriate for the actual base material and service condition.
What to Confirm With the Manufacturer Data Sheet
Before purchase, confirm the following on the datasheet or product page:
- Classification and AWS specification
- Recommended shielding gas
- Available diameters
- Typical operating position or positions, if stated
- Storage and handling requirements
- Any mechanical property or toughness data the manufacturer publishes
If any of those points are not shown on the page you are reviewing, they are Unknown (Verify). Do not fill the gap with assumptions or with a different brand’s datasheet.
Practical Buyer Guidance
For support teams, the key purchase risk is choosing a filler by classification only. Two wires with the same classification can still differ by manufacturer, intended gas, and published properties. That matters when you are supporting a WPS-driven shop or a field repair program.
When a buyer is asked to source ER100S-G, collect the following before ordering: job number, WPS number, base material, required diameter, spool size if applicable, shielding gas, and any code or customer requirement. If a field technician cannot provide those inputs, pause the order and verify the application.
Safety Notes
- Follow the site WPS and the filler metal manufacturer instructions.
- Use proper ventilation and fume control for all GMAW operations.
- Keep wire dry and clean. Do not use contaminated consumables.
- Do not weld from incomplete information on critical joints.
- If the job is safety-critical or code-controlled, verify the procedure with welding engineering or quality control before use.
FAQ
Is ER100S-G the right wire for all high-strength steel repairs?
No. It may be suitable for some high-strength low-alloy steel applications, but the correct choice depends on the WPS, base metal grade, service conditions, and code requirements.
Can I choose ER100S-G just because the strength number looks correct?
No. The classification alone is not enough. Verify the full procedure and manufacturer data sheet before using it.
What wire diameter should I order?
Unknown (Verify). Confirm the allowed diameter on the WPS and the specific product page or datasheet before ordering.
Does the filler metal finder page approve a procedure?
No. It is a selection tool. Use it to narrow choices, then verify against the WPS and supporting documentation.
Sources Checked
- ER100S-G MIG / GMAW Filler Metal: https://www.weldsupportparts.com/filler-metal-mig-er100s-g.html
- WSP Filler Metal Finder: https://www.weldsupportparts.com/filler-metal-finder.html
No additional product, ASIN, or internal-link data was provided for this draft.
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