What situations require a Clause 6 tested WPS rather than a prequalified WPS?

A tested WPS is required whenever your welding situation falls outside the prequalified provisions of Clause 5. Common triggers include: base metals not listed as prequalified, joint geometries outside the prequalified Annex B limits, welding processes not covered by prequalification, essential variables outside previously qualified ranges, or project specifications that prohibit prequalified procedures and explicitly require physical PQR testing.

What test specimens are required for a groove weld PQR under AWS D1.1?

For groove weld qualification, AWS D1.1 requires tensile test specimens and bend test specimens. The tensile specimen must meet minimum ultimate tensile strength equal to or above the base metal specification. Bend specimens (face bends, root bends, or side bends depending on base metal thickness) must pass without cracks exceeding the acceptance criteria. For base metal thicker than 3/8 in, side bends are typically substituted for full-thickness face and root bends.

How many test plates do you need to qualify a WPS?

AWS D1.1 specifies minimum test assembly and specimen counts based on process, joint type, the positions to be qualified, and the thickness range desired. A single test plate usually establishes one thickness bracket and one or more positions. To qualify additional positions or a wider thickness range, additional test assemblies may be required. Check the current edition's requirements for your specific process — counts differ between preprocess types.

Can you use another company's PQR to support your WPS?

AWS D1.1 generally requires the contractor responsible for production welding to have access to a valid PQR supporting each WPS. Using another fabricator's PQR may be permitted if the owner accepts it and the contractor can confirm the PQR's parameters are applicable to the current work. Contractual and specification requirements govern — verify with the owner and EOR before relying on a third-party PQR.

AWS D1.1 Clause 6 tested WPS: when prequalified falls short

Test-based WPS qualification under AWS D1.1 Clause 6: when prequalified provisions don't apply, what tests are required, and what the PQR must document.

Most structural fab shops run on prequalified WPS procedures under AWS D1.1 Clause 5. Prequalified status means you skip the physical testing and jump directly into production using established joint geometries and process limits that the code has already validated. But prequalification has a boundary. When your welding situation falls outside that boundary — because of the base metal, the joint geometry, the process, or the project specification — you enter the territory of Clause 6: qualification of welding procedures by test.

Understanding when Clause 6 testing is required and what it demands is essential for any CWI or QC manager who reviews WPS documentation. A shop that uses a prequalified WPS where a tested WPS is required has a procedural non-conformance, regardless of how good the welds look.

The Two Paths to a Valid WPS

AWS D1.1 gives fabricators two routes to a valid WPS:

Path 1 — Prequalified (Clause 5). The WPS is written to conform entirely to the prequalified provisions: the base metals are listed in Table 3.1 (or otherwise permitted), the joint geometry matches an Annex B prequalified detail, the process is one of those covered by prequalification (SMAW, SAW, GMAW, FCAW, GTAW), and all essential variables fall within the prequalified limits. No physical testing is required. The WPS document serves as its own qualification.

Path 2 — Tested (Clause 6). The WPS is developed by actually welding test assemblies under controlled conditions, then cutting and testing specimens. The test results are recorded in a Procedure Qualification Record (PQR). The WPS is then supported by that PQR and must stay within the essential variables listed in Table 6.6 as qualified by the test data.

The choice between the paths is not always the fabricator's to make. Some project specifications prohibit prequalified procedures and require tested qualification for all welds. Seismic applications under AWS D1.8 typically impose additional testing requirements. The owner or EOR may specify testing for any joint they consider structurally critical.

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

When Prequalification Falls Short

Even absent a specification mandate, certain situations push you out of Clause 5 and into Clause 6:

Non-prequalified base metals. AWS D1.1 lists base metals approved for prequalified use. Structural steels outside that list — higher-strength grades, specialty alloys, older or non-standard mill products — require tested qualification. Before assuming prequalification is available for an unusual grade, confirm the specific ASTM designation appears in the applicable table.

Joint geometry outside Annex B. Annex B covers a defined set of groove weld joint configurations: root openings, groove angles, root faces, and backer conditions. Any groove geometry that deviates from these figures — by dimension or by configuration — is non-prequalified. Shops that modify standard joint details to suit their fit-up tooling often unintentionally exit the prequalified zone.

Processes outside the prequalified list. Plasma arc welding, laser-beam welding, and other non-conventional processes are not covered by prequalification under AWS D1.1. Any WPS using these processes requires tested qualification.

Changes in essential variables. If a shop has a tested PQR but wants to expand production parameters beyond the tested range — more amperage, a different filler metal classification, a different shielding gas composition — the new parameters are not covered by the existing PQR. A new test is required. The essential variables governing this are in Table 6.6.

For a breakdown of when the prequalified path has limitations, see AWS D1.1 Clause 5 prequalified WPS limitations and prequalified WPS vs PQR cost comparison.

Structure of Clause 6 Testing

Clause 6 testing follows a defined workflow: prepare, weld, inspect, test, document.

Preparing the Test Assembly

Test assemblies are prepared to represent the type of joint being qualified: groove weld plate assemblies for structural butt joints, fillet weld assemblies for T-joint or lap joint qualification. The base metal used in the test assembly must be the same as (or a permitted substitute for) the production base metal.

The test assembly is welded using the parameters you intend to qualify — amperage, voltage, travel speed, heat input, preheat, interpass temperature, electrode classification, shielding gas, joint geometry. These parameters are all recorded during welding because they become the basis for the WPS range.

The welder who performs the test must be a qualified welder. The test should be observed by or conducted under the control of a CWI or responsible welding engineer.

Visual and NDE Inspection

Before cutting specimens, the test assembly undergoes visual inspection for cracks, incomplete fusion, and other visible discontinuities. AWS D1.1 may also require radiographic or ultrasonic testing of the test assembly before mechanical testing, depending on the applicable clauses for your situation.

If the test assembly fails visual or NDE, the qualification fails. You cannot salvage a failed test by selecting only the good-looking sections for specimen cutting.

Tensile Testing

Tensile specimens are cut from the test assembly and machined to the dimensions specified in AWS D1.1 (reduced-section specimens for groove welds). Each specimen is pulled to failure. The fracture must occur at or above the minimum specified tensile strength of the base metal — failing in the weld metal is acceptable provided the tensile strength requirement is met.

For joints between base metals of different strength levels, the governing tensile requirement is based on the lower-strength base metal.

Bend Testing

Guided bend tests evaluate the ductility and soundness of the weld cross-section. AWS D1.1 specifies the bend radius, the bend angle (typically 180°), and the acceptance criteria. Common specimen types:

Face bend — weld face in tension during bending; surfaces any lack of fusion at the root that opened during solidification
Root bend — weld root in tension; surfaces incomplete penetration or root defects
Side bend — cross-section of the weld in tension; used for thicker plates (typically above 3/8 in) because full-thickness face and root bends become impractical

Acceptance criteria: no crack or discontinuity exceeding 1/8 in measured in any direction after bending, with some exceptions for corner cracks at the edge of the specimen.

For more detail on bend test requirements and acceptance, see guided bend test PQR AWS D1.1 and PQR tensile and bend test requirements.

Macro Examination for Fillet Welds

If the qualification includes fillet welds, a macro specimen is cut from the test assembly and polished and etched to reveal the weld cross-section. The macro is examined for minimum fillet weld size, fusion to the base metal, and the presence of cracks or other unacceptable discontinuities. No tensile or bend testing is required for fillet-weld-only qualification.

What the PQR Must Document

The PQR is the record of what was actually done during the test — not what was intended, but what happened. AWS D1.1 specifies the required content:

All essential variables listed in Table 6.6 as actually measured and used during the test
Base metal specification, heat number if available, and thickness of the test assembly
Welding process and mode of operation (manual, semiautomatic, automatic)
Joint geometry as prepared and measured at fit-up
Filler metal classification, diameter, and heat or lot number
Shielding gas composition and flow rate
Current, polarity, voltage, wire feed speed (or amperage directly for stick processes), and travel speed — as actually measured, not as targeted
Preheat and interpass temperatures as measured
Number of passes and pass sequence
Post-weld heat treatment if applied
Test results: tensile strengths, fracture location, bend test outcomes, macro findings
Name and certification of the person witnessing and/or CWI signing the PQR

The PQR is a legal document. Changes to the actual test parameters are not permitted after the test — the PQR records what happened. If an error was made in welding that would have changed the results, the test must be repeated.

Qualified Range Established by the PQR

The PQR does not just document the test — it defines the range of welding parameters covered for production. Each essential variable in Table 6.6 has a qualified range derived from the test conditions.

For thickness, the PQR establishes both a minimum and maximum thickness qualified for production. Typically, the maximum is 2T (twice the test plate thickness) and the minimum is 1/2T, with specific limits stated in the standard. Welding production base metal thicker than the maximum qualified thickness requires a new PQR or supplemental testing.

For process parameters (amperage, voltage, travel speed), the WPS states a range — not a single value. That range must be supported by the PQR. The parameters stated on the WPS may be broader than the tested values only to the extent permitted by Table 6.6 for each variable.

A shop with multiple PQRs on file can combine them to support a single WPS that covers a wider range — provided the essential variables from each PQR collectively cover the WPS range without gaps. See multiple PQRs supporting a single WPS.

PQR Review During CWI Audit

When reviewing a WPS supported by a tested PQR, the CWI or third-party auditor should verify:

The PQR test plate was the same base metal type and within the thickness qualified for production
The test was performed by a qualified welder and the PQR is signed by an authorized individual
All essential variables in Table 6.6 are documented on the PQR
The WPS essential variables are within the qualified range established by the PQR
Test results (tensile strengths, bend pass/fail) are documented and meet the acceptance criteria
If CVN testing was required, Table 6.8 supplementary variables are also addressed

A PQR that is missing any of these elements creates a gap in your procedure qualification chain. Gap = non-conformance. Fix it before the third-party audit, not during.

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