Does a 1G groove weld PQR qualify fillet welds in the flat position?

Yes, generally. A WPS qualified for groove welds in a given position covers fillet welds in the same position for the same process and base metal group. A 1G qualification covers flat-position (1F) fillet welds; it does not automatically cover horizontal (2F) fillet welds unless 2G groove qualification is also in place.

Can I use a prequalified SMAW WPS for both groove and fillet welds?

Yes. A prequalified WPS under AWS D1.1:2025 Clause 5 may list both groove and fillet weld applications provided the process, base metal, filler metal, and joint details all fall within prequalified limits. The WPS must explicitly state both joint types in its application statement.

Do fillet weld procedures require separate tensile and bend tests?

No. AWS D1.1 does not require tensile or transverse bend tests for fillet welds. When qualification is based on fillet weld testing only, the required tests are a fillet weld break test and a macroetch section—not the tensile and bend evidence produced by a groove weld PQR.

What is the minimum fillet weld size under AWS D1.1:2025?

Minimum fillet weld size is a function of the thicker part being joined and is tabulated in AWS D1.1:2025. Sizes generally range from 3/16 in for thinner material up to 5/16 in for material over 3/4 in thick. Always verify with the current edition table for your material thickness.

Groove weld PQR coverage for fillet welds under AWS D1.1

A PQR qualified on groove welds extends to fillet welds under AWS D1.1—but position and process rules limit that coverage. Here is where the lines are.

A PQR developed on a groove weld test coupon covers more than groove weld production. Under AWS D1.1:2025, a qualified WPS for groove welds also qualifies the procedure for fillet weld applications — provided the process, base metal group, filler metal, and position all fall within the qualified range. Knowing exactly where that coverage ends prevents running fillet welds under a WPS whose PQR was tested in an incompatible configuration.

The Coverage Rule

AWS D1.1 establishes that groove weld procedure qualification covers fillet welds for the same welding process, base metal group, and positions within the qualified range. This is not the same as saying any groove WPS covers any fillet weld. The essential variables from Table 6.6 still apply — if the production fillet weld uses a different process, a different filler classification, or falls outside the position range of the PQR, the groove qualification does not extend coverage.

The practical effect is that most shops need fewer WPSs than they expect. A single groove weld PQR, properly scoped, can support a wide range of fillet weld production work without a separate fillet-specific PQR.

Position Coverage Mapping

Groove weld position qualification maps to fillet weld position coverage as follows:

1G (flat groove) qualifies flat (1F) fillet welds
2G (horizontal groove) qualifies flat and horizontal (1F, 2F) fillet welds
3G (vertical groove) qualifies flat, horizontal, and vertical (1F, 2F, 3F) fillet welds
4G (overhead groove) qualifies flat, horizontal, and overhead (1F, 2F, 4F) fillet welds
3G + 4G combined qualifies all fillet weld positions (1F, 2F, 3F, 4F)

Shops that weld both groove and fillet joints in all positions typically qualify 3G + 4G on the PQR. A 2G-only groove qualification is common in facilities that primarily weld flat and horizontal, but crews that weld column splices and beam-to-column connections in overhead need 4G coverage or a separate qualification. Verify the exact position mapping against your governing edition — the table is the controlling document.

The Testing Difference

Groove weld PQRs require tensile specimens and bend specimens — side bends or face/root bends depending on plate thickness — per the mechanical test requirements in Clause 6. Those tests verify weld metal tensile strength and root or fusion ductility.

Fillet weld procedures do not require tensile or bend tests. When qualification rests on fillet weld testing only — rather than derived from groove qualification — AWS D1.1 requires a fillet weld break test and a macroetch section. The macroetch verifies fusion at the root and confirms the minimum effective throat is achieved. The break test fractures the assembly and exposes the weld cross-section for visual evaluation.

This is one reason groove PQR coverage is preferred for fillet work: the tensile and bend results provide more mechanical evidence, and the groove qualification covers both joint types without a second set of test coupons or a second PQR entry in the procedure library.

Prequalified Procedures and Fillet Welds

A prequalified WPS under Clause 5 of AWS D1.1:2025 may cover both groove and fillet weld applications provided:

The joint configuration falls within the prequalified joint details referenced in Clause 5
The base metal is on the prequalified base metal list
The filler metal is prequalified for the process
The preheat meets the prequalified requirements

For prequalified SMAW WPSs, a single document can list "groove and fillet welds" in its application statement. What it cannot do is extend prequalified coverage to an application that requires qualification testing by design specification. If the contract or owner specification requires a tested PQR for the CJP groove weld on a given connection, the prequalified route is not available for that joint — the fillet weld coverage question is secondary to the groove weld qualification requirement.

For a detailed look at the prequalified WPS pathway, see prequalified WPS under AWS D1.1 Clause 5.

What Still Triggers a Separate WPS

Even with groove-to-fillet coverage in place, these scenarios require either a separate WPS or a requalified WPS:

Different welding process. A GMAW groove PQR does not cover SMAW fillet production. Process is an essential variable; the coverage rule operates within process, not across processes.

Different base metal group. Moving to a different group in AWS D1.1 Table 6.9 means the base metal essential variable from Table 6.6 has changed. A WPS qualified on Group I base metal does not cover Group II production fillet welds without a PQR that covers Group II.

Filler classification change. Switching from ER70S-6 to ER70S-3 is a change in filler classification per Table 6.6. A separate WPS is needed unless the current PQR explicitly covers both classifications. For the filler essential variable rows in detail, see AWS D1.1:2025 Table 6.6 explained.

Heat input outside the qualified range. Fillet welds on thin material often require lower heat input than groove welds on thick plate. If the PQR was run at heat inputs suited for heavy plate, the documented range may not extend down to the parameters needed for thin-material fillet work. The heat input range from the PQR bounds all production welding under that WPS — groove and fillet alike. See heat input control and documentation on a WPS for how the range is calculated and recorded.

Fillet Weld-Only Procedures

Some shops choose a fillet weld-specific PQR for processes like GMAW short-circuit transfer where low heat input is the primary parameter concern. A fillet weld procedure qualification under AWS D1.1 tests:

Fillet weld break test: fracture the test assembly and examine the fracture face for incomplete fusion, porosity, and slag inclusions
Macroetch: cut a transverse section, etch, and photograph; measure leg size, effective throat, and fusion at the root

These tests verify workmanship and fusion geometry but do not produce tensile or CVN data. Shops that need a full mechanical data set behind every procedure — for example, to satisfy owner-specified requirements demanding tensile evidence for all joint types — should run groove weld PQRs and derive fillet coverage from them.

Applying This in Practice

The efficient approach for a structural fab shop is to qualify groove weld procedures at 3G + 4G for each applicable process and base metal group combination. That single PQR covers all fillet weld positions, reduces the total number of procedure qualification records in the library, and provides the tensile and bend mechanical data that satisfies the broadest range of owner requirements.

Track the qualified range explicitly in the WPS application statement: process, base metal group(s), filler classification, position, and heat input range. Any production assignment that falls outside any of those dimensions needs a separate WPS before work starts.

For a structured review of what to verify before any weld assignment, see CWI WPS review checklist and WPS qualification range: thickness and position.

WPS and PQR management — including groove-to-fillet position mapping and heat input range tracking — is built into the Solo and Pro plans at wpswelding.com/pricing.

Rule library based on AWS D1.1:2025; verify against your governing edition.