Can a single test plate satisfy both AWS D1.1 and ASME IX PQR requirements?

Yes, but you must design the test assembly to satisfy both codes' requirements simultaneously — the right base metals, sufficient thickness, and enough specimens to cover both. The challenge is that the codes have different essential variable lists, so coverage under one doesn't automatically provide coverage under the other.

Does ASME IX recognize AWS D1.1 prequalified procedures?

No. ASME IX does not recognize prequalified WPS provisions. Every ASME IX WPS must be supported by a PQR with actual mechanical test results. AWS D1.1 prequalification does not satisfy ASME IX qualification requirements.

Which code's essential variables are more restrictive — D1.1 or ASME IX?

It varies by variable. ASME IX is generally more prescriptive on base metal groupings (P-numbers) and filler metal classifications (F-numbers), while AWS D1.1 is more specific about position qualification ranges and some process-specific parameters. The safest approach is to list both codes' essential variables side by side and apply the more restrictive requirement for each.

Do the mechanical test acceptance criteria differ between the two codes?

Yes. AWS D1.1 and ASME IX have different tensile strength minimums for some base metals, different guided-bend acceptance criteria, and different CVN impact requirements. The test report must demonstrate compliance with both sets of criteria, which sometimes means running additional specimens.

Single PQR for Both AWS D1.1 and ASME IX: Is It Possible?

Qualifying one test weld for both AWS D1.1 and ASME Section IX — essential variable differences, test coupon layout, and how to document a dual-code WPS/PQR.

Why Shops Need Dual-Code Qualification

Fabrication shops that serve both structural steel and pressure vessel or piping markets face a recurring documentation burden: maintaining separate WPS/PQR libraries for AWS D1.1 structural work and ASME Section IX pressure equipment work. When both codes apply to the same shop using the same processes and the same welders, the duplication is expensive and the maintenance risk is real — a procedure change logged in one system may not make it into the other.

The good news is that the codes don't prohibit a single test weld assembly from providing the basis for qualification under both. Shops that plan carefully at the PQR stage can produce one set of mechanical test results that satisfies both codes, reducing library overhead and simplifying the audit trail.

The important caveat: "one test weld" is not the same as "one PQR document." You will almost certainly need two separate PQR forms — one formatted to AWS D1.1 Annex M requirements and one formatted to ASME QW-483 — both referencing the same mechanical test results. The test data is shared; the documentation structure is separate.

The Essential Variable Problem

The core planning challenge is that AWS D1.1 and ASME IX define qualification differently at the process variable level, and the lists don't align one-to-one.

AWS D1.1 essential variables are listed in Table 6.6 of the 2025 edition for SMAW, SAW, GMAW, FCAW, and GTAW processes. CVN supplementary essential variables are in Table 6.8. A change to any Table 6.6 variable requires a new PQR for AWS D1.1 purposes.

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

ASME IX essential variables are defined per process under QW-250 through QW-290. The lists overlap with D1.1 but are not identical. Some variables that are essential under one code are nonessential under the other. Minimum preheat, for example, is treated differently in terms of what triggers requalification. Current type and polarity are handled differently too. Neither code's essential variable list is a safe proxy for the other's.

Base metal groupings are the most common planning trap. AWS D1.1:2025 groups base metals by chemistry and mechanical properties per Table 6.9. ASME IX uses the P-number system from QW-420. These systems don't align cleanly. A qualification that covers a given P-number under ASME IX does not automatically cover the equivalent AWS D1.1 base metal group, and the reverse is equally true. You must verify coverage independently under each code using each code's own grouping table.

See D1.1 vs. ASME Section IX: Key WPS Differences for a side-by-side comparison of the structural differences in how the two codes approach qualification.

Designing the Test Assembly for Dual Coverage

Careful upfront planning is what makes dual qualification work. Here is what needs to be decided before the test plate is fabricated.

Base metal selection. The test plate must appear in both the AWS D1.1 Table 6.9 group you need and the ASME IX P-number you need. ASTM A516 Grade 70 (ASME P-1, AWS D1.1 Group II) and ASTM A572 Grade 50 (ASME P-1, AWS D1.1 Group II) are the most common choices for shops doing both structural and pressure vessel work. A516-70 in particular is a natural fit because it appears constantly in pressure vessel fabrication and has a clear structural steel analog.

Test plate thickness. ASME IX qualification thickness ranges (QW-451) and AWS D1.1 thickness qualification ranges differ. Running the test plate at the maximum thickness your shop will commonly encounter maximizes the qualified range under both codes. A 1-1/2-inch (38 mm) test plate typically qualifies a broader thickness range than a 3/8-inch plate, and the added material is a minor cost compared to the cost of running a second qualification test later.

Specimen count and extraction plan. List out the required specimens from each code and add them up before dimensioning the test plate. For a typical SMAW groove weld test at 1-inch plate, you might need:

AWS D1.1: two reduced-section tensiles, four guided bends (or side bends per thickness), plus CVN specimens if required by contract
ASME IX: two reduced-section tensiles (QW-462.1), four guided bends (QW-462.2), and an all-weld-metal tensile (QW-462.1(b)) if required

The all-weld-metal tensile in ASME IX is often the specimen that requires extra plate length. Plan the test plate geometry to accommodate it before the test plate is cut.

Filler metal. The filler metal must be covered under both codes' classification systems. ASME IX F-number groupings and the AWS A5 series classifications generally align, but verify for the specific electrode you intend to use. Some low-alloy electrodes that are common in structural work are grouped differently under ASME IX than their A5-series classification would suggest.

What to Record on the Test Plate

The actual test weld must be performed with the parameters documented exactly as used — not the WPS range, but the actual values for current, voltage, travel speed, wire feed speed, preheat, and interpass temperature. This is a requirement under both codes, but it's frequently recorded incorrectly. Common mistakes:

Recording the WPS range instead of the actual measured values during the test weld
Failing to record interpass temperature at multiple points through the fill passes
Not recording shielding gas flow rate when it's an essential variable under one or both codes

Both codes' PQR forms ask for actual values, not ranges. If the lab report shows that preheat was measured once at the start of the test and never again, that's a documentation gap an auditor will flag.

Two PQR Forms, One Data Set

Once the mechanical test results are in hand, you produce two PQR forms from the same data.

The AWS D1.1 PQR should follow the Annex M form guidance. The ASME IX PQR uses QW-483. Both ask for overlapping information — base metal, filler metal, joint design, preheat, PWHT, process variables — but the structure and specific fields differ. Work through each form independently rather than trying to copy one into the other; the variable ordering and the specific requirements for certification differ between the two.

See ASME IX QW-482 and QW-483 WPS/PQR Forms Explained for the ASME form field requirements. For the AWS D1.1 side, Reading a PQR Test Report covers common field interpretation questions that come up during the D1.1 PQR review.

The mechanical test report from the lab is referenced by both PQR forms. That reference must include the lab name, accreditation standard, test date, specimen identification, and the actual test results for each specimen — not just a pass/fail summary.

Welder Qualification: A Separate Problem

Procedure qualification and welder performance qualification (WPQ) are independent. A welder qualified under AWS D1.1 is not automatically qualified under ASME IX, and vice versa. If your shop needs welders qualified under both codes — which is typical in a dual-code shop — that requires two separate WPQ test events per process per position, or a joint WPQ test designed to satisfy both codes' requirements simultaneously.

The joint WPQ approach follows the same logic as the dual PQR: design the test joint to the more restrictive of the two codes' requirements (thickness, position, joint type), weld it with the parameters from the dual-code WPS, test to both codes' WPQ acceptance criteria, and produce two separate WPQ records from the same test.

See Welder Performance Qualification Under AWS D1.1 for the D1.1 WPQ framework. The period-of-effectiveness rules differ between the two codes — AWS D1.1 uses a 6-month continuity requirement under Clause 6.4.1, while ASME IX uses a similar provision under QW-322 — so the welder continuity tracking must cover both code clocks, not just one. See ASME IX Welder Qualification Period and QW-322 Renewal for the ASME IX side of that requirement.

Managing the Library Long-Term

The dual-code qualification reduces the test cost at qualification time, but it creates an ongoing library management obligation: any time you want to extend coverage (new process, new base metal, new position), you must evaluate both codes' essential variable lists to determine whether a new PQR is required under one or both. A change that is nonessential under ASME IX might be essential under AWS D1.1, and failing to requalify under one code while the other is satisfied is the gap that shows up in third-party audits.

If your shop is managing a cross-code WPS/PQR library, WPS Welding's qualification record tools can organize procedure qualifications by applicable code and flag essential variable changes that trigger requalification requirements under either standard — keeping your library synchronized without manual tracking.