Can a single WPS cover both SMAW root and FCAW-G fill passes?

Yes. AWS D1.1 allows a WPS to cover multiple welding processes within a single document, either as a single WPS referencing two process sections or as a combined procedure. The essential variables from Table 6.6 apply to each process independently — a change that triggers requalification for SMAW does not automatically affect the FCAW-G essential variable scope, and vice versa, though both must remain within their qualified ranges.

Do I need separate PQRs for each process in a multi-process WPS?

Not necessarily. AWS D1.1 permits a single PQR test plate that uses multiple processes in sequence, mirroring the production intent — SMAW root pass, then FCAW-G fill, for example. The test plate assembly and mechanical test specimens evaluate the completed weld. However, if the processes are qualified at different times or from different test plates, the WPS must reference both supporting PQRs and the qualified ranges from each.

What happens if the SMAW root pass is changed to GTAW on a qualified multi-process WPS?

Changing the welding process is an essential variable under Table 6.6 for all covered processes (SMAW, SAW, GMAW, FCAW, GTAW). Substituting GTAW for the SMAW root pass constitutes an essential variable change for the root pass segment, which requires requalification of the WPS for that portion of the joint. The FCAW-G fill segment qualification may remain valid if its essential variables have not changed.

How do I write the WPS form when two processes are involved?

The Annex M WPS form has parameter fields for each welding process. Fill in the SMAW parameters (electrode classification, diameter, current range, polarity) for the root pass, and the FCAW-G parameters (wire classification, diameter, gas, WFS range, voltage) for fill and cap. Designate which passes use which process — pass sequence by process is a required WPS element under AWS D1.1.

Multi-Process WPS: How Essential Variables Apply When Processes Combine

When one WPS covers SMAW root plus FCAW-G fill, essential variable tables govern each process segment independently. Here's how to qualify and document it correctly.

A SMAW root pass followed by FCAW-G fill and cap is one of the most common hybrid welding sequences in structural steel fabrication. The two-process approach lets welders take advantage of SMAW's positional flexibility and arc control for root pass integrity, then switch to FCAW-G's deposition efficiency for the fill passes that dominate the volume and the schedule.

From a WPS qualification standpoint, combining two processes under one document is straightforward in concept — but it requires careful application of the essential variable tables to each process segment. The most frequent mistake is applying essential variable scope as if the WPS were a single process, when in fact each process section carries its own independent list of changes that trigger requalification.

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

The Fundamental Rule: One Essential Variable Table Per Process

AWS D1.1:2025 Table 6.6 defines essential variables for five covered processes: SMAW, SAW, GMAW, FCAW, and GTAW. Each process has its own row entries in the table. When a WPS covers multiple processes — SMAW plus FCAW-G, for example — Table 6.6 applies to each process independently.

This means the qualified parameter range for SMAW (electrode classification, current type and polarity, position, preheat) is governed by the SMAW rows in Table 6.6. The qualified parameter range for FCAW-G (wire classification, shielding gas, wire diameter, current range, voltage, interpass temperature) is governed by the FCAW rows. A change that falls within the qualified range for one process has no effect on the essential variable status of the other — they are evaluated in parallel, not jointly.

The practical consequence: when you change an FCAW-G essential variable — say, substituting a different wire classification — you must requalify the WPS for the FCAW-G process. If the SMAW root pass parameters have not changed, the SMAW portion of the WPS remains qualified from the original PQR. You can write a supplemental PQR for the FCAW-G change and update the WPS to reference both PQRs without re-running the mechanical tests on the root pass segment.

What Counts as an Essential Variable for Each Process

For the SMAW root pass under Table 6.6, the most commonly triggered essential variables in structural practice are:

Change in the AWS A5 filler metal specification (e.g., A5.1 to A5.5)
Change in electrode classification (e.g., E7018 to E7016) — if the new classification has a different strength level or supplemental designator affecting notch toughness
Increase in base metal thickness beyond the qualified range (150% of the test plate for groove welds, subject to position and joint type qualifications)
Change in position to one not qualified on the test plate
Change in current type or polarity (DCEP to DCEN, or AC)
Decrease in preheat or interpass temperature below the qualified minimum

For the FCAW-G fill pass segment, the commonly triggered essential variables are:

Change in the AWS A5 filler metal specification (A5.20 to A5.36, or vice versa) — note that under Table 6.6, the 2025 edition removed A5.36 from the GMAW/FCAW interchangeable group (row 4)
Change in shielding gas composition or flow rate beyond the qualified range (see shielding gas essential variable documentation)
Change in wire diameter beyond the qualified range
Addition or deletion of flux or supplemental backing (groove welds)
Change in voltage range or WFS range beyond the qualified limits
Change from flux-cored to metal-cored (FCAW to GMAW classification change)

For CVN-qualified welds, the Table 6.8 supplementary essential variables layer onto both process segments independently. A change in heat input that affects toughness must be evaluated against the CVN test conditions for whichever process segment the change affects. See CVN supplementary essential variables under Table 6.8 for how the supplementary table interacts with the main essential variable scope.

Qualifying the Multi-Process WPS: Test Plate Options

When qualifying a multi-process WPS from scratch, the most efficient approach is a single test plate that uses both processes in sequence — SMAW root, then FCAW-G fill — exactly as the production welds will be made. The test plate assembly simulates the production joint: the root pass opens the groove, the SMAW welds the root, and the FCAW-G fills the remainder.

The mechanical test specimens (tensile, guided bend, macro sections) evaluate the completed weld regardless of how many processes contributed to it. The PQR documents:

Which process was used for each pass or pass range
The parameters for each process during the test weld (amperage, voltage, WFS, travel speed, preheat, interpass)
The test results for the full assembly

Both process sections are then referenced in the WPS as qualified by this single PQR. If the SMAW root parameters are later changed — for example, electrode diameter increased — a supplemental SMAW PQR is needed; the original FCAW-G qualification carries over.

When processes are qualified at different times or from different test programs, the WPS references multiple PQRs. The header of the Annex M WPS form includes a field for supporting PQR numbers — list all PQRs whose essential variable ranges apply to the parameters in this WPS.

Pass Designation and Process Assignment

The WPS must clearly assign each pass or group of passes to the correct process. "Root pass: SMAW, E7018, 3/32 inch, DCEP, 70–90A. Fill passes 2–5: FCAW-G, E71T-1C, 0.045 inch, 75% Ar/25% CO₂, 180–220A." This level of specificity serves two purposes: it gives the welder unambiguous instructions, and it gives the inspector a parameter baseline against which to check production conditions.

A WPS that says "SMAW or FCAW-G as required" without designating which process applies to which passes is non-conforming — the essential variable scope cannot be evaluated without knowing which process governs each segment of the joint. See how to write an AWS D1.1 WPS for the full list of required WPS elements and how pass designation fits into the document structure.

Welder Qualification Scope Under a Multi-Process WPS

Welder performance qualification (WPQ) under AWS D1.1 also follows process lines. A welder qualified by a 3G SMAW test is qualified for SMAW in the flat, horizontal, and vertical positions within the qualified thickness range — but that qualification does not extend to FCAW-G. If the welder switches to FCAW-G for the fill passes, they must also hold a valid FCAW-G WPQ.

This is a common oversight on structural jobs. A shop qualifies welders for the SMAW root pass and assumes the qualification covers the full weld. When the fill passes are FCAW-G, a separate WPQ for FCAW-G is required for each welder making those passes. The welder's name on the weld traveler tells the inspector which processes the welder used; both processes must appear on the qualification matrix.

Review welder qualification scope under AWS D1.1 to confirm the qualification ranges that carry between groove and fillet weld test types and between process configurations.

Changes That Affect the Entire Multi-Process WPS

Some changes in a multi-process WPS trigger requalification across both process segments:

Base metal group change. A change in base metal to a different group in AWS D1.1 Table 4.9 — for example, from Group I to Group II steel — affects preheat qualification, which applies to the full weld regardless of process.
Joint design change. A change in groove geometry (included angle, root opening, root face dimension) that falls outside the prequalified or qualified range affects the joint itself, not the process. Both process segments are weld into that joint, so the joint geometry requalification affects the full WPS.
Position change. Adding a position not covered by the test plate (for example, adding 4G when the test was only 2G) requires requalification for the joint position — this applies to all processes covered by that WPS.
Base metal thickness. Changing to a base metal thickness outside the qualified range from the test plate affects the WPS as a whole; both process sections must qualify within the limits of the supporting PQR(s).

Changes to CVN supplementary essential variables under Table 6.8 may also affect the full weld scope — coordinate with the engineer if the project specifies Charpy requirements for any weld configuration.

Documentation: Keeping the WPS Readable

The Annex M WPS form was designed primarily for single-process procedures. When filling it in for a multi-process procedure, use the separate sections or additional continuation sheets to document each process's parameter ranges distinctly. Do not mix SMAW and FCAW-G parameters in the same amperage/voltage fields — an inspector using the WPS to check production parameters needs to know which row applies to which process without ambiguity.

Name the WPS clearly: "WPS-001 (SMAW/FCAW-G)" or "WPS-CJP-3G-SMAW-ROOT-FCAW-FILL" tells anyone picking up the document what to expect. In a WPS library with dozens of documents, process designators in the title reduce the chance of a welder picking up the wrong WPS for the job at hand. See WPS numbering scheme best practices for naming conventions that scale across a full WPS library.

For shops managing multi-process procedures across multiple projects, wpswelding.com/pricing supports WPS document libraries with process-level parameter management, so essential variable scope is tracked and visible rather than buried in individual PDF files.

Multi-process WPS qualification is not more complex than single-process — it simply requires applying the same logic in parallel to each process segment. The essential variable table governs each process independently, the PQR documents each process's test conditions, and the WPS form designates exactly which process applies to which passes. Keeping those three elements aligned — and maintaining separate welder qualifications for each process — is what separates a defensible multi-process qualification package from one that generates audit findings.