What does a CWI verify on a WPS before welding begins?

A CWI checks that the WPS is applicable to the base metal, process, position, and joint configuration in the production weld. They confirm the WPS is signed, the supporting PQR (if required) is on file, and the electrode/filler metal in use matches the WPS. This pre-weld review is the most cost-effective inspection step — problems caught before arc strike cost far less than a completed weld that must be removed.

Who is responsible for workmanship compliance during welding?

The fabricator is responsible for the work. The CWI (whether employed by the fabricator, contractor, or owner's representative) verifies it. AWS D1.1 distinguishes between the fabricator's in-process quality control and the CWI's inspection role. A CWI does not perform the work but has authority to require correction of non-conforming work.

Is interpass temperature recorded on the WPS, and can a welder exceed it?

Yes — the maximum interpass temperature is a WPS parameter derived from the PQR. Exceeding the maximum interpass temperature during production violates the WPS. If CVN (Charpy V-Notch) testing was part of the PQR qualification, interpass temperature is also a Table 6.8 supplementary essential variable, making an overage a requalification trigger, not just a workmanship deviation.

What's a typical CWI hold point during structural welding production?

Common hold points include: joint fit-up and tack weld review (before any fill pass begins), root pass inspection (for CJP groove welds, especially where back-gouging will occur), and final visual inspection prior to NDE. Owner- or contract-specified ITP (Inspection and Test Plan) may add additional hold points.

AWS D1.1 workmanship: what CWIs verify against the WPS

Fabrication and workmanship requirements in AWS D1.1:2025 that inspectors verify against the active WPS — joint fit-up, interpass temperature, cleaning, heat input, and more.

A WPS is not a document that lives in the filing cabinet after it's signed. It travels onto the fabrication floor and becomes the legal standard against which every weld is judged. When a CWI checks production welding, they are comparing observed practice against what the WPS specifies — and against AWS D1.1's fabrication requirements that govern tolerances the WPS doesn't set on its own.

This article walks through the workmanship checks that CWIs perform in production, where those checks tie back to the WPS, and where they tie back directly to the structural code.

The distinction between WPS parameters and workmanship requirements

AWS D1.1:2025 addresses fabrication in two places:

WPS parameters — the process variables (amperage, voltage, travel speed, preheat, interpass, position, progression) that are set during procedure qualification and documented on the WPS. These are verified against the WPS.
Fabrication requirements — joint preparation, fit-up tolerances, cleaning between passes, distortion control, and similar workmanship standards that are set by the code independent of what process is being used. These are verified against the applicable clauses in AWS D1.1:2025.

A production weld can satisfy its WPS exactly and still fail a workmanship inspection if the joint fit-up was out of tolerance before welding began. Both categories must be correct.

Pre-weld inspection: the highest-leverage step

Before the first arc strike, a CWI should verify:

WPS applicability. Does the WPS cover the base metal, process, joint configuration, position, and material thickness of the production weld? A WPS for flat-position fillet welds does not cover overhead groove welds. A WPS qualified on A36 does not automatically cover A572 Gr. 65 (depending on base metal groupings). Confirming applicability before work begins prevents a situation where a completed weld must be removed because it was made under the wrong WPS.

Joint preparation and fit-up. AWS D1.1:2025 specifies tolerances for groove angles, root openings, root face dimensions, and alignment for prequalified joint geometries. For joints qualified by PQR, the production joint must fall within the tolerances the WPS specifies. A root opening wider than the WPS maximum or a groove angle tighter than the minimum can affect fusion and may void the procedure qualification.

Base metal condition. The joint faces should be free of paint, scale, oil, moisture, and other contamination at the time of welding. Mill scale on faying surfaces is often acceptable for fillet welds (per code) but the WPS may impose a stricter cleanliness requirement. For prequalified groove welds, joint faces must be suitable for welding as specified.

Electrode/filler metal verification. The electrode or wire in use must match the classification and diameter on the WPS. This is a fast check with a real consequence: using the wrong filler metal can be an essential variable exceedance, and for low-hydrogen processes (E7018, ER70S, E71T-1), the storage and conditioning requirements in AWS D1.1 also apply.

Preheat. If the WPS specifies minimum preheat — whether driven by base metal carbon equivalent, thickness, or code table requirements — the CWI should verify preheat is achieved before welding begins and maintained as required. Preheat is not optional, and a welder who skips it on a cold morning is not in compliance with the WPS regardless of how the weld looks afterward. See preheat verification methods and documentation for measurement and recording practices.

In-process inspection: interpass and pass sequence

During welding, CWIs verify ongoing compliance with:

Interpass temperature. The WPS specifies a maximum interpass temperature. The inspector or QC technician should monitor and record interpass temperature for each pass, particularly on multi-pass welds with high heat accumulation (thick-section SAW welds, heavily reinforced fillet welds). Interpass temperature control matters for mechanical properties and, when CVN is required, is a Table 6.8 supplementary essential variable. See the coverage of CVN supplementary essentials in Table 6.8 for how that interaction works.

Pass sequence. For multi-pass CJP groove welds, the WPS often specifies a pass sequence or bead placement that controls distortion and ensures fusion at the fusion faces. Deviating from the sequence — for example, filling one side entirely before starting the other — can introduce distortion that makes subsequent passes difficult and can reduce mechanical performance.

Interpass cleaning. AWS D1.1 requires slag removal and appropriate cleaning between passes. For SMAW, every pass must be cleaned of slag before the next pass is deposited. For FCAW-S, slag removal is especially important because the slag system differs from FCAW-G and can mask fusion issues if left in place. CWIs look for slag inclusions in the completed weld that could indicate inadequate interpass cleaning.

Root pass inspection on CJP groove welds. For full-penetration welds with back-gouging, the CWI should inspect the back-gouged surface before the back weld is deposited. The gouge must reach sound weld metal — visual inspection confirms the groove shape is appropriate and MT or PT inspection (if specified by the contract or ITP) confirms freedom from cracks at the root.

Post-weld workmanship: before NDE

After welding is complete but before NDE or final acceptance, CWIs perform a visual inspection per AWS D1.1. The visual acceptance criteria are independent of the NDE method and represent a baseline check that all welds must pass.

Key visual checks include:

No cracks, crater cracks, or surface porosity exceeding the acceptance limits
Weld face geometry within the allowed convexity and concavity limits
Undercut depth within the maximum allowed (AWS D1.1:2025 specifies limits by weld type and loading condition)
Weld size meets the drawing callout (both throat and leg for fillet welds)
No incomplete fusion visible at the weld toes
Craters are filled

See visual acceptance criteria for AWS D1.1 structural welds for the full list. Visual inspection is not a substitute for NDE on joints that require UT or RT, but it is a required prerequisite — NDE on a visually non-conforming weld is not accepted practice.

Documenting workmanship observations

CWIs doing in-process inspection should record hold point sign-offs, any nonconformances found, and the disposition of each nonconformance (repair, accept-as-is with engineer approval, or rejection). These records become part of the audit packet.

A WPS library that's well-maintained, with each procedure linked to its PQR and the welder qualification records showing coverage for the required positions and progressions, makes the CWI's job faster. The inspection record only needs to confirm the correct WPS was used — not dig through files to verify its qualification basis.

For WPS management that connects procedures to PQRs, welder qualifications, and production inspection records, see our WPS software for fab shops. Related reading: CWI WPS review checklist and weld inspection hold points for CWIs.

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