Low Alloy & High Strength
ER90S-G
ER90S-G is a low-alloy solid welding wire classified under AWS A5.28. Unlike specific alloy classifications such as B3, B9 or Ni2, the G classification does not define one single fixed alloy chemistry. The actual product chemistry, mechanical properties and application should therefore be verified from the manufacturer’s technical documentation and qualified welding procedure.
ER90S-G Welding Wire
ER90S-G is an AWS A5.28 low-alloy solid welding wire classification for applications requiring ER90-strength weld metal and manufacturer-defined alloy chemistry.
The key characteristic of ER90S-G is the G classification. Unlike specific classifications such as ER90S-B3 or ER90S-B9, G does not identify one single standardized alloy system.
The actual chemical composition is established by the manufacturer within the applicable AWS classification requirements.
Therefore, ER90S-G should be selected according to:
Base Material + Actual Chemistry + Mechanical Requirements + Service Conditions + WPS/PQR
ER90S-G at a Glance
Item | Details |
|---|---|
AWS Classification | ER90S-G |
AWS Specification | AWS A5.28 / ASME SFA-5.28 |
Product Type | Solid Welding Wire / TIG Filler Rod |
Strength Classification | ER90 |
Alloy System | Manufacturer-defined low-alloy chemistry |
Welding Processes | GMAW/MIG, GTAW/TIG |
Typical Applications | Low-alloy steel / industrial applications |
Product Form | Spool / Rod |
Key Selection Factor | Actual chemistry + base material + WPS/PQR |
Documentation | TDS / MTC / CoA |
What Makes ER90S-G Different?
The most important point for buyers is that ER90S-G is not a single fixed alloy composition.
The classification can be understood as:
- ER — electrode or filler metal classification
- 90 — 90 ksi-class tensile-strength level
- S — solid wire
- G — general classification with manufacturer-defined alloy chemistry
This means the AWS classification alone does not tell the buyer the complete alloy chemistry.
Two products carrying the ER90S-G classification should not automatically be assumed to have identical chemical compositions or identical application recommendations.
For material approval, review the specific manufacturer's:
TDS + Chemical Composition + Mechanical Properties + MTC/CoA
This distinction is particularly important when ER90S-G is being considered for engineered, pressure-equipment or code-controlled applications.
ER90S-G Technical Characteristics
Chemical Composition
ER90S-G does not represent one universally fixed chemical composition.
Depending on the specific product design, controlled alloying elements may include:
- Carbon
- Manganese
- Silicon
- Chromium
- Nickel
- Molybdenum
- Copper
The actual chemistry must be confirmed from the manufacturer's technical documentation.
For critical applications, batch-specific MTC/CoA should be reviewed rather than relying only on the ER90S-G designation.
Mechanical Properties
ER90S-G belongs to the ER90 strength classification.
Typical minimum classification requirements in the supplied product information include:
Property | Minimum |
|---|---|
Tensile Strength | 620 MPa / 90 ksi |
Yield Strength | 530 MPa / 77 ksi |
Elongation | 17% |
Actual mechanical properties depend on the specific product and testing conditions.
Relevant variables may include:
- Welding process
- Shielding gas
- Heat input
- Welding parameters
- PWHT
- Test temperature
- Weld-metal chemistry
For project qualification, use the manufacturer's current TDS/MTC and qualified WPS/PQR.
Where Can ER90S-G Be Used?
There is no single universal base material for every ER90S-G product.
The appropriate application depends on the actual chemistry and mechanical properties of the selected product.
Potential application areas include:
Low-Alloy Steel Fabrication
ER90S-G may be considered for compatible low-alloy steels where an ER90-strength weld metal is required.
Industrial Equipment
Selected ER90S-G products may be used for industrial equipment and heavy machinery requiring higher-strength weld metal.
Piping
Where permitted by the material specification and qualified welding procedure, ER90S-G may be considered for selected piping applications.
Pressure Equipment
For pressure-equipment applications, the actual chemistry, mechanical properties, impact requirements, heat treatment and applicable code should be verified before material approval.
Structural Fabrication
ER90S-G may be considered for selected high-strength structural applications when permitted by the applicable specification and WPS/PQR.
ER90S-G Welding Processes
GMAW / MIG
ER90S-G may be supplied as solid welding wire for GMAW/MIG applications according to the specific product specification.
Key welding parameters include:
- Wire diameter
- Shielding gas
- Welding current
- Voltage
- Wire-feed speed
- Travel speed
- Heat input
Actual parameters should follow the qualified WPS.
GTAW / TIG
Depending on product form, ER90S-G may also be supplied as TIG filler rod.
GTAW/TIG can be considered for applications requiring:
- Controlled deposition
- Pipe root passes
- Precision welding
- Critical joints
ER90S-G Welding Procedure Considerations
The welding procedure should be developed around the actual ER90S-G product, not the classification alone.
Important welding controls may include:
Preheat → Interpass Temperature → Heat Input → Controlled Cooling → PWHT
The applicable requirements depend on:
- Base material
- Material thickness
- Joint design
- Welding process
- Service conditions
- Applicable code
- WPS/PQR
For critical applications, the consumable should be qualified with the intended base material and welding procedure.
ER90S-G Selection Guide
When purchasing ER90S-G welding wire, the most important question is not simply:
“Is it ER90S-G?”
Instead, confirm the following:
Base Material
Identify the exact steel grade, specification and thickness.
Weld-Metal Strength
Confirm whether the required weld-metal strength is within the ER90 classification.
Actual Chemistry
Request the manufacturer's chemical composition and verify compatibility with the base material and service conditions.
Toughness
Check whether Charpy impact testing is required and identify the required test temperature.
Service Conditions
Consider operating temperature, loading conditions and the intended service environment.
Welding Process
Confirm whether the application requires:
GMAW/MIG or GTAW/TIG
Heat Treatment
Determine whether preheat, controlled cooling or PWHT is required by the WPS, material specification or applicable code.
Qualification
Confirm that the selected ER90S-G product is covered by the required WPS/PQR.
ER90S-G Compared With Other Welding Wire Classifications
ER90S-G vs ER90S-B3
| ER90S-G | ER90S-B3 |
|---|---|---|
Classification | G | B3 |
Strength | ER90 | ER90 |
Alloy Chemistry | Manufacturer-defined | Specific Cr-Mo system |
Typical Material | Product dependent | P22 / T22-related |
Selection Focus | Actual chemistry + WPS | Cr-Mo compatibility + WPS |
Typical Service | Product dependent | Elevated-temperature service |
ER90S-G and ER90S-B3 share an ER90 strength level, but they are not automatically equivalent.
B3 identifies a specific Cr-Mo alloy system, while G does not.
ER90S-G vs ER90S-B9
| ER90S-G | ER90S-B9 |
|---|---|---|
Classification | G | B9 |
Strength | ER90 | ER90 |
Alloy Chemistry | Manufacturer-defined | Specific Cr-Mo system |
Typical Material | Product dependent | P91/T91-related |
Selection Focus | Actual chemistry + WPS | Cr-Mo compatibility + WPS/PQR |
Typical Service | Product dependent | High-temperature service |
For P91/T91-related applications, do not select ER90S-G based on strength classification alone. The consumable must meet the specific alloy, mechanical, heat-treatment and qualification requirements of the application.
ER90S-G vs ER80S-G
| ER90S-G | ER80S-G |
|---|---|---|
Strength Classification | ER90 | ER80 |
Tensile Strength Level | ~90 ksi | ~80 ksi |
Alloy Chemistry | Manufacturer-defined | Manufacturer-defined |
Product Type | Solid wire | Solid wire |
Main Selection Factor | Strength + actual chemistry | Strength + actual chemistry |
The primary classification difference is the strength level.
However, ER90S-G should not automatically be treated as a replacement for ER80S-G. Base material, mechanical requirements and WPS/PQR determine suitability.
Can ER90S-G Replace Another Welding Wire?
Not automatically.
A substitution should be evaluated using:
Base Material + Consumable Chemistry + Mechanical Properties + Toughness + Service Conditions + WPS/PQR + Applicable Code
For example:
- ER90S-G is not automatically equivalent to ER90S-B3.
- ER90S-G is not automatically equivalent to ER90S-B9.
- ER90S-G is not automatically interchangeable with ER80S-G.
The fact that two consumables have the same or similar strength classification does not establish metallurgical or code compliance.
For a proposed substitution, review the complete product documentation and qualification requirements before ordering.
ER90S-G Procurement Checklist
For a quotation or technical review, provide:
1. AWS Classification
ER90S-G
2. Base Material
Steel grade and specification
3. Diameter
Required wire or rod diameter
4. Welding Process
GMAW/MIG or GTAW/TIG
5. Application
Piping, structural, machinery, pressure equipment, etc.
6. Service Temperature
Operating or design temperature where relevant
7. Quantity
Required order quantity
8. Certification
TDS, MTC, CoA, impact data or other project documents
This information helps determine whether the available ER90S-G product matches the intended application.
Diameter and Packaging
ER90S-G can be supplied in different diameters and packaging formats according to product availability and customer requirements.
Possible formats include:
- MIG/GMAW spools
- TIG/GTAW rods
- Different wire diameters
- Standard packaging
- Customized packaging
Packaging and available diameters should be confirmed with the specific product before ordering.
Quality and Technical Documentation
For ER90S-G projects, buyers may request:
- Technical Data Sheet (TDS)
- Mill Test Certificate (MTC)
- Certificate of Analysis (CoA)
- Chemical composition
- Mechanical properties
- Impact test data
- Certificate of Conformity
- Packaging information
- Project-specific documentation
Because ER90S-G does not define one fixed alloy chemistry, the manufacturer's technical documentation is an important part of product approval.
Frequently Asked Questions
What is ER90S-G welding wire?
ER90S-G is an AWS A5.28 low-alloy solid welding wire classification with an ER90 strength level and manufacturer-defined alloy chemistry.
What does G mean in ER90S-G?
The G designation represents a general classification in which the alloy chemistry is not defined as one specific standardized alloy system like B3 or B9.
What is ER90S-G used for?
Its application depends on the actual product chemistry and qualified welding procedure. Potential applications include compatible low-alloy steel, industrial equipment, piping, structural and pressure-equipment applications.
Is ER90S-G a high-strength welding wire?
ER90S-G belongs to the ER90 strength classification, with a tensile-strength level of approximately 90 ksi.
What is the difference between ER90S-G and ER90S-B3?
ER90S-G has manufacturer-defined alloy chemistry, while ER90S-B3 is a specific Cr-Mo classification associated with P22/T22-related applications.
What is the difference between ER90S-G and ER90S-B9?
ER90S-G is a general classification with manufacturer-defined chemistry, while ER90S-B9 is a specific Cr-Mo classification associated with P91/T91-related applications.
Can ER90S-G replace ER90S-B3?
Not automatically. The base material, consumable chemistry, mechanical requirements and qualified WPS/PQR must support the substitution.
Can ER90S-G replace ER90S-B9?
Not automatically. P91/T91-related welding requires the appropriate Cr-Mo chemistry and qualification requirements.
Can ER90S-G replace ER80S-G?
Not automatically. The two classifications have different strength levels and must be evaluated against the actual welding requirements.
What welding processes can use ER90S-G?
Depending on product form, ER90S-G may be supplied for GMAW/MIG and GTAW/TIG applications.
Does ER90S-G require PWHT?
PWHT depends on the base material, thickness, welding procedure and applicable code. Follow the qualified WPS/PQR.
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