4.1 WPS Qualification Requirements, PQR Coupon Testing & Mechanical Evaluation
Key Takeaways
- When a Welding Procedure Specification (WPS) does not satisfy every codified requirement of Clause 5 prequalification, formal qualification by destructive mechanical testing under Clause 6 is mandatory.
- A Procedure Qualification Record (PQR) is a certified, legally binding factual document recording the actual welding parameters, base metals, filler metals, and destructive test results used to qualify one or more WPSs.
- Standard PQR test plate assemblies include Complete Joint Penetration (CJP) groove coupons (Figure 6.6), Partial Joint Penetration (PJP) groove coupons (Figure 6.15), and Fillet Weld Soundness coupons (Figure 6.16).
- Nondestructive testing—consisting of 100% visual inspection and full-length Radiographic (RT) or Ultrasonic Testing (UT)—is mandatory on CJP PQR test plates prior to cutting mechanical test specimens.
- A minimum discard of 1 in. (25 mm) from each plate end is strictly required when extracting reduced-section tension, guided bend, macroetch, and Charpy V-Notch (CVN) test specimens.
Last updated: August 2026
The Legal and Engineering Mandate for WPS Qualification
Under AWS D1.1/D1.1M:2025, structural welding procedures must be proven capable of producing sound welded joints with the specified mechanical properties (tensile strength, ductility, and notch toughness) before production welding commences. While Clause 5 permits prequalification for a narrow envelope of proven processes, base metals, and joint details, Clause 6 (Qualification), Part B (Welding Procedure Specification [WPS] Qualification) governs all procedures that fall outside those prequalified boundaries.
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| AWS D1.1 WPS QUALIFICATION FRAMEWORK |
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| |
| +---------------------------------------------------------------------------------+ |
| | DOES THE PROPOSED PROCEDURE SATISFY CLAUSE 5? | |
| +---------------------------------------------------------------------------------+ |
| | | |
| YES NO |
| v v |
| +---------------------------+ +---------------------------+ |
| | PREQUALIFIED WPS | | QUALIFICATION BY | |
| | (Clause 5 Exemption) | | TESTING (Clause 6) | |
| +---------------------------+ +---------------------------+ |
| | * Written WPS required | | * Weld standard coupon | |
| | * No coupon testing | | * Visual & RT/UT NDT | |
| | * Proven processes only | | * Mechanical testing | |
| | * Listed steels only | | * Document data on PQR | |
| | * Standard groove details | | * Write WPS from PQR | |
| +---------------------------+ +---------------------------+ |
| |
+-----------------------------------------------------------------------------------------+
Mandatory Qualification Triggers under Clause 6
A contractor or fabricator must qualify a WPS by mechanical testing under Clause 6 whenever any of the following conditions occur:
- Non-Prequalified Welding Processes: Any procedure utilizing Gas Metal Arc Welding in the short-circuiting transfer mode (GMAW-S), Gas Tungsten Arc Welding (GTAW / TIG), Electroslag Welding (ESW), Electrogas Welding (EGW), Laser Beam Welding (LBW), or Electron Beam Welding (EBW).
- Unlisted Base Metals: Any base metal not explicitly tabulated in Table 5.6 (e.g., proprietary steels, foreign specifications such as EN 10025 or JIS G3101 lacking dual ASTM certification, AISI 4140, AISI 1018/1020, ASTM A516).
- Non-Standard Joint Geometries: Any groove angle, root opening, root face, or radius outside the codified ranges and tolerances of Figure 5.1 (CJP) or Figure 5.2 (PJP).
- Unapproved Consumables: Any filler metal, flux, or shielding gas combination not listed in Table 5.7 or Table 5.10.
- Modified Electrical Variables: Arc parameters, heat input ranges, or travel speeds outside the prequalified boundaries of Clause 5.
- Contractual Toughness Requirements: Any project specification requiring Charpy V-Notch (CVN) impact toughness qualification, which prequalification cannot provide.
The PQR vs. WPS Relationship
Understanding the distinct legal and operational functions of the Welding Procedure Specification (WPS) and the Procedure Qualification Record (PQR) is fundamental to structural welding quality assurance.
| Document | Standard Form | Primary Function | Legal Status & Revisions |
|---|---|---|---|
| Procedure Qualification Record (PQR) | AWS D1.1 Form M-1 / J-1 | A certified historical record of actual welding parameters recorded during the fabrication of a test coupon and the subsequent destructive/nondestructive test results. | Permanent, certified document. Cannot be revised or altered after signing, except to correct typographical errors. Serves as the evidentiary foundation for WPSs. |
| Welding Procedure Specification (WPS) | AWS D1.1 Form M-2 / J-2 | A written instructional document providing specific parameter ranges (volts, amps, travel speed, preheat, joint design) to welders and inspectors for shop and field production welding. | Living working document. May be revised, updated, or re-issued within the essential variable ranges authorized by the supporting PQR(s) without retesting. |
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| PQR TO WPS RELATIONSHIP ARCHITECTURE |
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| |
| +------------------------------------+ +------------------------------------+ |
| | PQR NO. 101 (ACTUALS) | | PQR NO. 102 (ACTUALS) | |
| +------------------------------------+ +------------------------------------+ |
| | * Process: SMAW (E7018) | | * Process: SAW (F7A2-EM12K) | |
| | * Plate Thickness: 1.0 in. (25 mm) | | * Plate Thickness: 1.0 in. (25 mm) | |
| | * Current: 165 A, 24 V, 6.2 ipm | | * Current: 450 A, 30 V, 18.0 ipm | |
| | * Tensile: 76.4 ksi (Pass) | | * Tensile: 74.8 ksi (Pass) | |
| | * Bends: 4 Side Bends (Pass) | | * Bends: 4 Side Bends (Pass) | |
| +------------------------------------+ +------------------------------------+ |
| \ / |
| \ / |
| v v |
| +----------------------------------------------------+ |
| | WPS NO. 201-COMBINED (QUALIFIED RANGES) | |
| +----------------------------------------------------+ |
| | * Root / Hot Pass: SMAW (140 - 185 A, 22 - 26 V) | |
| | * Fill / Cap Passes: SAW (380 - 520 A, 28 - 33 V) | |
| | * Qualified Thickness Range: 1/8 in. to Unlimited | |
| | * Qualified Positions: Flat (1G) Groove & Fillet | |
| +----------------------------------------------------+ |
| |
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[!NOTE] A single PQR may support multiple WPSs across different joint configurations and thickness ranges. Conversely, multiple PQRs (e.g., one PQR for SMAW root passes and another PQR for SAW fill/cap passes) may be combined to support a single multi-process production WPS.
Standard PQR Test Coupon Assemblies (Figures 6.5, 6.6, 6.7)
Clause 6 establishes standardized plate, pipe, and tubular test assemblies for procedure qualification. The choice of test weldment dictates the scope of qualification.
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| FIGURE 6.6: CJP GROOVE WELD PLATE TEST COUPON |
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| |
| |<------------------------- Length: Min. 15 in. (380 mm) -------------------------->| |
| +----------------------------------------------------------------------------------+ |
| | Discard Zone (Min. 1.0 in. / 25 mm) | |
| | - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - | |
| | Side Bend (or Root Bend) Specimen | |
| | - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - | |
| | Reduced-Section Tension Specimen No. 1 | |
| | - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - | |
| | Side Bend (or Face Bend) Specimen | |
| |=============================== WELD SEAM ========================================| |
| | Side Bend (or Root Bend) Specimen | |
| | - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - | |
| | Reduced-Section Tension Specimen No. 2 | |
| | - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - | |
| | Side Bend (or Face Bend) Specimen | |
| | - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - | |
| | Discard Zone (Min. 1.0 in. / 25 mm) | |
| +----------------------------------------------------------------------------------+ |
| |<-------- Width: Min. 7 in. -------->|<-------- Width: Min. 7 in. -------->| |
| |<-------------------- Total Assembly Width: Min. 14 in. -------------------------->| |
| |
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1. CJP Groove Weld Plate Coupon (Figure 6.6)
- Dimensions: Minimum length of 15 in. (380 mm) in the welding direction; minimum width of 7 in. (180 mm) per plate member (14 in. [350 mm] total width).
- Discard Requirement: A minimum of 1 in. (25 mm) must be discarded from both ends of the test weldment to eliminate arc start and crater defects from the mechanical test specimens.
- Thickness (T): Plate thickness selected determines the qualified production thickness range per Table 6.2.
2. PJP Groove Weld Plate Coupon (Figure 6.15)
- Designed to verify the effective weld throat (E) for non-standard groove angles and root openings.
- Requires transverse cross-sectioning and polishing for macroetch examination to verify weld penetration and throat depth without internal defects.
3. Fillet Weld Soundness Coupon (Figure 6.16)
- Utilizes a T-joint or lap-joint assembly to verify fillet weld soundness, penetration into the root apex, and profile.
- Requires visual inspection, macroetch cross-sections, and guided bend or fillet weld break testing.
4. Pipe and Tubular Test Assemblies (Figures 10.14 and 10.15)
- Standard pipe coupons fabricated in 1G (rotated), 2G (fixed vertical), 5G (fixed horizontal), or 6G (fixed inclined at 45°) positions to qualify pipe and box tube connections.
Required Mechanical Specimens & NDT Protocol (Table 6.2)
AWS D1.1 Clause 6.10 mandates a strict sequence of non-destructive and destructive examinations for every PQR test weldment.
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| PQR TESTING & EVALUATION SEQUENCE |
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| |
| [1. VISUAL INSPECTION] ---> [2. NONDESTRUCTIVE TESTING] ---> [3. MECHANICAL TESTS] |
| * 100% of coupon length * 100% RT or UT on CJP coupon * Tension tests (2) |
| * Per Clause 6.10.1 * Mandatory per Cl. 6.10.2 * Bend tests (4) |
| * No cracks, full flush * Discard ends included * Macroetch / CVN |
| |
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Mandatory NDT Prior to Sectioning (Clause 6.10.2)
Before any mechanical test specimens are cut from a CJP groove weld test plate or pipe:
- Visual Examination (VT): The entire length of the weldment must be visually inspected and meet the requirements of Clause 6.10.1 (no cracks, complete fusion, complete joint penetration, no excessive undercut or reinforcement).
- Radiographic (RT) or Ultrasonic Testing (UT): The CJP groove weldment must undergo 100% volumetric examination per Clause 8. Any internal defect that violates the acceptance criteria of Clause 8 mandates rejection of the coupon—meaning destructive sectioning cannot proceed on defective weldments.
Specimen Extraction Matrix for CJP Plate Coupons (Table 6.2)
| Plate Coupon Thickness (T) | Tension Specimens (Reduced-Section) | Transverse Root Bend | Transverse Face Bend | Transverse Side Bend | Total Mechanical Specimens |
|---|---|---|---|---|---|
| 1/8 in. ≤ T < 3/8 in. (3–10 mm) | 2 | 2 | 2 | — | 6 specimens |
| T = 3/8 in. (10 mm) | 2 | 2 (or 0) | 2 (or 0) | 0 (or 4) | 6 specimens |
| T > 3/8 in. (10 mm) | 2 | — | — | 4 | 6 specimens |
[!IMPORTANT] For plate thicknesses of 3/8 in. (10 mm), the contractor has the option to test either 2 Root Bends and 2 Face Bends OR 4 Side Bends. For all plate thicknesses greater than 3/8 in., Side Bends are mandatory (root and face bends are not permitted).
Test Your Knowledge
Which statement accurately describes the legal and technical relationship between a Procedure Qualification Record (PQR) and a Welding Procedure Specification (WPS) under AWS D1.1?
A
B
C
D
Test Your Knowledge
A structural fabricator welds a 1-inch (25 mm) thick plate test coupon to qualify a CJP groove welding procedure per AWS D1.1 Figure 6.6. According to Table 6.2, which mechanical test specimens must be extracted and successfully tested?
A
B
C
D
Test Your Knowledge
Under AWS D1.1 Clause 6.10.2, what mandatory quality control step must be completed on a CJP groove weld PQR test assembly before cutting mechanical test specimens?
A
B
C
D