What makes a filler metal 'prequalified' under AWS D1.1?

A filler metal is prequalified when its AWS A5-series classification appears in the approved list within AWS D1.1:2025 Clause 5. Using a prequalified filler metal means no PQR testing is required for that filler—as long as every other Clause 5 requirement is also met. A filler metal outside the approved list requires a tested WPS qualified under Clause 6.

Can I substitute a different heat or lot of the same electrode classification on a prequalified WPS?

Yes. Filler metal classification—the AWS A5 designation—is what's prequalified, not the specific manufacturer's heat number. You can change heat numbers, lot numbers, or even manufacturers as long as the new filler carries the identical AWS classification. Filler metal classification substitution that changes the A5 designation is an essential variable on a tested WPS; on a prequalified WPS it either remains prequalified (if the new classification is also on the list) or requires moving to Clause 6.

Does the 2025 edition of AWS D1.1 change which filler metals are prequalified?

Yes. The 2025 edition introduced changes to how A5.36 classification designators are handled in the rules for tested WPS (Table 6.6). For prequalified WPS, the Clause 5 filler metal list reflects the current approved classifications. If you are converting a WPS written to the 2020 edition, verify that all filler metals still appear in the 2025 approved list.

What happens if I discover mid-project that my filler metal isn't on the prequalified list?

You have two options: switch to a prequalified filler metal classification that meets the mechanical property requirements, or convert the WPS to a tested procedure under Clause 6 by running a PQR with the current filler metal. The second option requires a PQR test plate, mechanical testing, and documentation—plan for schedule impact. For future projects, verify filler metal prequalified status before committing to a prequalified WPS approach.

Oct 31, 20268 min read

AWS D1.1 Prequalified Filler Metal Classifications Explained

Which AWS A5-series filler metal classifications qualify for prequalified WPS under AWS D1.1:2025 Clause 5? Process-by-process breakdown for SMAW, GMAW, FCAW, SAW, and GTAW.

WPS Filler Metal AWS D1.1 Prequalified WPS SMAW GMAW FCAW SAW

New to procedures? Start with WPS welding: what a welding procedure specification is, with a filled-in example.

A fabricator builds an entire WPS library on the prequalified pathway—Clause 5, no PQR testing—and the approach holds up until an audit finds that one electrode classification used across several procedures does not appear in the D1.1:2025 prequalified list. That single gap converts multiple prequalified WPS into unqualified procedures. The welds produced under them are now unsupported by documentation until the situation is remediated.

Filler metal classification is one of the first checks on any prequalified WPS review. This article covers which process–filler combinations earn prequalified status under AWS D1.1:2025 and how to verify compliance on the shop floor.

Rule library based on AWS D1.1:2025; verify against your governing edition. The approved filler metal classifications in Clause 5 are edition-specific.

The Prequalified Filler Metal Concept

Prequalified WPS under AWS D1.1:2025 Clause 5 allow fabricators to write welding procedures without PQR testing—but only when every element of the WPS conforms to the Clause 5 requirements. Filler metal is one of those elements.

The code lists specific AWS A5-series filler metal classifications that are approved for prequalified use. The logic is that these classifications have well-established mechanical properties and deposition behavior verified through the filler metal qualification standards themselves. Because the classification already certifies the filler metal's properties, D1.1 can permit its prequalified use without additional testing.

Using any filler metal whose AWS A5 classification is not on the prequalified list invalidates prequalified status for that WPS. That does not mean the weld is bad—it means the WPS lacks documented qualification. The remedy is either substituting a prequalified classification or qualifying the procedure under Clause 6.

Process-by-Process Overview

SMAW (Shielded Metal Arc Welding)

SMAW electrodes prequalified under D1.1 Clause 5 come from AWS A5.1 (carbon steel) and A5.5 (low alloy steel). The classifications are limited to the EXX1X and EXX2X families—electrodes with minimum yield strengths compatible with structural carbon and low-alloy steel.

The common shop electrodes that fall in prequalified territory:

E6010 and E6011 (A5.1): frequently used for root passes in structural CJP groove welds
E7016, E7018, and E7024 (A5.1): the workhorses of structural SMAW
E7018-1 (A5.1): the low-temperature, high-toughness variant used when CVN requirements apply
E8018-C3 and similar low-alloy designations (A5.5): for higher-strength base metals

Electrodes with H-suffix designators (e.g., E7018-H4R) retain prequalified status provided the base classification is on the list. The H-suffix is not a separate classification but an additional tested property for diffusible hydrogen content.

Electrodes from A5.4 (stainless) or A5.11 (nickel alloy) are not in the D1.1 prequalified list and require tested WPS for structural applications. For stainless welding under AWS D1.6, that code governs prequalified filler metal eligibility.

GMAW (Gas Metal Arc Welding)

Prequalified GMAW wire classifications under D1.1 Clause 5 come primarily from AWS A5.18 (carbon steel). The standard prequalified wires:

ER70S-2, ER70S-3, ER70S-4, ER70S-6 (A5.18): these are the most common structural GMAW consumables and all carry prequalified status
ER70S-G classifications: G-designator wires require the user to verify that the specific wire's properties meet D1.1 minimum mechanical property requirements—the G is a catch-all that does not carry a defined chemistry, so prequalified status depends on meeting the property floor

Metal-cored wires from A5.36 have been an area of change between the 2020 and 2025 editions. The 2025 edition revised how certain A5.36 designators are treated in the essential variable tables for tested WPS (Table 6.6). For prequalified WPS, verify the specific A5.36 classification against the current Clause 5 approved list rather than assuming 2020 edition status carries forward.

See GMAW ER70S-6 vs ER70S-3: WPS Selection Under AWS D1.1 for a comparison of these two classifications in structural production.

FCAW (Flux-Cored Arc Welding)

FCAW prequalified status under D1.1 Clause 5 is more restrictive than SMAW or GMAW. Not all T-designator flux-cored electrodes are prequalified. The key distinctions:

Prequalified gas-shielded (FCAW-G) electrodes come from AWS A5.20 (carbon steel) or A5.36. The E70T-1, E70T-9, E70T-12, and similar classifications with defined impact toughness properties are generally included in the prequalified list.

Excluded FCAW-G classifications include E70T-4 and certain other T-designations whose metallurgical behavior or lack of tested toughness properties makes them unsuitable for prequalified structural use. Verify each T-suffix against the Clause 5 list.

Self-shielded (FCAW-S) electrodes from AWS A5.20 and A5.29: prequalified status applies to specific classifications. E71T-8 (A5.20) and E71T-11 (A5.20) are the two most commonly used self-shielded electrodes in structural work. Both are on the prequalified list under specific conditions—E71T-8 carries better CVN toughness performance and is more broadly applicable, while E71T-11 has restrictions regarding minimum preheat requirements and maximum heat input ranges. See FCAW-S E71T-8 vs E71T-11: Electrode Selection Under AWS D1.1 for the comparison.

Self-shielded electrodes cannot be substituted for gas-shielded in the same WPS without a process change—a WPS that specifies FCAW-G cannot use an E71T-11 electrode simply because the strength designation matches.

SAW (Submerged Arc Welding)

SAW prequalified filler metal classification covers the wire-flux combination. The classification system from AWS A5.17 (carbon steel) and A5.23 (low alloy steel) designates the flux and wire together: for example, F7A0-EM12K identifies a flux-wire combination that produces 70-ksi minimum tensile strength, all-weld-metal Charpy impact tested at 0°F, using an EM12K wire.

Prequalified SAW combinations must come from A5.17 or A5.23 (for structural carbon and low-alloy steel applications) and must produce minimum mechanical properties consistent with the structural base metal being joined. Flux-wire combinations with designators outside the prequalified classes require tested WPS.

The flux classification affects the chemistry of the deposited weld metal through both the flux formulation and the wire chemistry, which is why both are specified in the WPS and why changing either is an essential variable under Table 6.6 for tested procedures—and must remain within the prequalified combination for prequalified procedures.

See SAW Flux and Wire Essential Variables Under AWS D1.1 for a deeper look at how flux-wire classification changes trigger requalification.

GTAW (Gas Tungsten Arc Welding)

GTAW (TIG) prequalified filler metals under D1.1 Clause 5 come from AWS A5.18 (ER70S-2, ER70S-3, ER70S-6 solid wire, same as GMAW) and A5.28 (low-alloy steel wire). GTAW is less common in structural steel fabrication but appears in root pass work on high-restraint joints and specialty applications.

The tungsten electrode itself (from AWS A5.12) is not classified by the D1.1 prequalified filler list—tungsten electrode type is specified in the WPS but does not independently determine prequalified status.

Classification vs. Manufacturer: What the WPS States

A common documentation question: the WPS lists the electrode classification (e.g., E7018), not the specific manufacturer or product name. This is intentional and correct. The AWS A5 classification is the prequalified unit, not the brand.

Production welds can use any manufacturer's E7018 electrode as long as the packaging confirms the AWS A5.1 classification. The CWI should verify the electrode package classification matches the WPS on the shop floor. A manufacturer's proprietary product name alone is not sufficient—the AWS designation must be visible on the label.

For heat traceability and lot control, the lot number and manufacturer are recorded on the filler metal use log, but these do not change the prequalified status of the electrode. See Filler Metal Lot Control and Traceability Under AWS D1.1 for the recordkeeping requirements.

When the Filler Isn't Prequalified

The path forward when a selected filler metal does not appear in the Clause 5 approved list:

Option 1 — Substitute a prequalified filler. If an equivalent classification exists in the prequalified list that meets the design's mechanical property requirements, switching to that electrode is the cleanest fix. The WPS is revised, no PQR is needed, and the project continues under the prequalified framework.

Option 2 — Qualify under Clause 6. Prepare and test a PQR using the non-prequalified filler metal. This requires a test plate welded per the proposed WPS conditions, followed by mechanical testing (tensile, bend, CVN if applicable). Once the PQR passes, the WPS is supported by test data and the filler metal's non-prequalified status is no longer an issue.

Option 3 — Review the edition. If the project's governing edition is 2020 and the fabricator has moved to 2025 for their WPS template, verify whether the filler metal in question was prequalified under the governing edition. Edition mismatch between the WPS template and the project specification sometimes creates apparent conflicts that are resolved by identifying the correct edition's Clause 5 list.

CWI Verification at the Joint

Before welding starts, the CWI's pre-weld inspection should confirm that the electrode on the welder's bench matches the WPS. Check:

AWS A5 classification on the electrode package — does it match the WPS exactly?
H-suffix, if required — if the WPS specifies E7018-H4R, an E7018 without the H4R suffix is not compliant
Electrode condition — low-hydrogen electrodes must be in a heated quiver or freshly drawn from an oven; unsealed packages in ambient shop air may have exceeded moisture limits for the H-suffix to remain valid. See Low Hydrogen Electrode Storage and Conditioning

Any departure between the electrode on the floor and the WPS is a pre-weld nonconformance. Resolve it before striking an arc—substituting after the fact produces unsupported welds.

Summary

Filler metal prequalified status under AWS D1.1:2025 Clause 5 is process-specific and classification-specific:

SMAW: A5.1 and A5.5 EXX1X/EXX2X families — E6010, E6011, E7016, E7018, E8018-series all covered
GMAW: A5.18 ER70S-series are generally prequalified; A5.36 metal-cored require per-classification verification in the current edition
FCAW-G: E70T-1, T-9, T-12 and similar from A5.20/A5.36 are listed; E70T-4 and some others are excluded
FCAW-S: E71T-8 and E71T-11 are listed with specific conditions; verify restrictions on each
SAW: A5.17/A5.23 flux-wire combinations producing minimum specified mechanical properties
GTAW: A5.18 and A5.28 solid wire classifications

The safest practice: before committing to a prequalified WPS, confirm every electrode and filler wire classification against the current Clause 5 list. A 15-minute check at project setup prevents a documentation crisis mid-fabrication.

For a broader look at the prequalified WPS framework, see Prequalified WPS Under AWS D1.1 Clause 5 and Prequalified vs Qualified by Test: Cost and Risk. Ready to build and manage a D1.1-compliant WPS library? See the WPS Welding platform.

FAQ

Frequently asked.

What makes a filler metal 'prequalified' under AWS D1.1?: A filler metal is prequalified when its AWS A5-series classification appears in the approved list within AWS D1.1:2025 Clause 5. Using a prequalified filler metal means no PQR testing is required for that filler—as long as every other Clause 5 requirement is also met. A filler metal outside the approved list requires a tested WPS qualified under Clause 6.
Can I substitute a different heat or lot of the same electrode classification on a prequalified WPS?: Yes. Filler metal classification—the AWS A5 designation—is what's prequalified, not the specific manufacturer's heat number. You can change heat numbers, lot numbers, or even manufacturers as long as the new filler carries the identical AWS classification. Filler metal classification substitution that changes the A5 designation is an essential variable on a tested WPS; on a prequalified WPS it either remains prequalified (if the new classification is also on the list) or requires moving to Clause 6.
Does the 2025 edition of AWS D1.1 change which filler metals are prequalified?: Yes. The 2025 edition introduced changes to how A5.36 classification designators are handled in the rules for tested WPS (Table 6.6). For prequalified WPS, the Clause 5 filler metal list reflects the current approved classifications. If you are converting a WPS written to the 2020 edition, verify that all filler metals still appear in the 2025 approved list.
What happens if I discover mid-project that my filler metal isn't on the prequalified list?: You have two options: switch to a prequalified filler metal classification that meets the mechanical property requirements, or convert the WPS to a tested procedure under Clause 6 by running a PQR with the current filler metal. The second option requires a PQR test plate, mechanical testing, and documentation—plan for schedule impact. For future projects, verify filler metal prequalified status before committing to a prequalified WPS approach.