The SMAW root / SAW fill-and-cap combination is one of the most productive multiprocess approaches for thick CJP groove welds in structural fabrication. SMAW gives the welder visual control over the root opening on plates that come in with fitup variation; SAW delivers deposition rates that can be three to five times higher than SMAW for the remaining passes. The pairing is common on bridge girder splices, heavy transfer beams, and crane runway beam splices where plate thickness runs from 1½ in through 4 in.

Getting the WPS and PQR documentation right for a combination process requires understanding how AWS D1.1:2025 applies essential variables separately to each process — and how qualification earned by one process does not automatically extend to the other.

Why SMAW Root + SAW Fill?

Root pass control is the main driver. SAW cannot see the joint root clearly because the arc is buried under flux; if the root face or root opening is out of tolerance, SAW operators lack the visual feedback to compensate. A skilled SMAW welder can adjust technique, electrode angle, and pause-and-fill on a tight root without stopping to re-fit the joint.

Once the root is fused and sound, the remaining fill and cap passes are where efficiency matters. A single 5/32 in SAW electrode at 450 A deposits roughly three times the weight per hour that an E7018 at the same diameter does. On a 2½ in deep CJP groove, that difference translates directly to per-joint cost.

The combination also keeps the flux-shielded benefit of SAW — lower hydrogen content in the fill and cap — while allowing a SMAW root process that is straightforwardly prequalified under D1.1 Clause 5 for most structural joint geometries.

Qualification Requirements Under AWS D1.1:2025

Two qualification paths are available.

Prequalified combination. If both process segments individually meet all the requirements of Clause 5, the combination WPS is prequalified and requires no PQR. The SMAW root must use a prequalified electrode classification, current type, position, and joint geometry. The SAW fill and cap must independently satisfy Clause 5 SAW prequalification requirements — joint geometry, current limits, flux classification, and wire diameter. Because the joint is shared, the groove geometry must simultaneously satisfy both the SMAW prequalified root geometry (root face, root opening) and the SAW fill requirements (adequate bevel angle for flux drainage, minimum depth-to-width ratio in each SAW pass).

Tested combination. When either process segment falls outside prequalified limits, or when the engineer or owner specification requires a tested WPS, a PQR is required under Clause 6. The test plate must demonstrate both processes in the sequence they will be used in production. You cannot run a SMAW-only PQR for the root and a separate SAW-only PQR for fill and then combine them unless each separate PQR individually covers the full required thickness range — a common misunderstanding.

Essential Variables: Process-by-Process Tracking

AWS D1.1:2025 Table 6.6 lists essential variables that trigger requalification. For a combination WPS, each essential variable must be evaluated against the process it governs. A change that affects SMAW does not automatically requalify the SAW portion, and vice versa.

SMAW essential variables for the root pass (reference Table 6.6, Row entries applicable to SMAW):

  • Filler metal F-number change (e.g., E6010 F3 → E7018 F4 requires requalification)
  • A-number change (filler metal chemical composition group)
  • Base metal P-number or Group Number change
  • Joint design change (groove angle, root face, root opening beyond prequalified tolerance)
  • Vertical progression direction if welding vertically (uphill vs. downhill is an essential variable for SMAW)
  • Preheat decrease below the PQR minimum

SAW essential variables for fill and cap passes:

  • Change in wire-flux classification (wire F-number and flux classification are essential variables)
  • Change in current type or polarity
  • Increase in bead width in a single pass beyond the PQR maximum
  • Change in multiple-wire configuration (single-wire vs. tandem is an essential variable; see Table 6.6)
  • Preheat decrease below the PQR minimum; interpass maximum temperature increase beyond 100°F above PQR maximum is also essential per the 2025 edition

Rule library based on AWS D1.1:2025; verify against your governing edition (the AHJ or contract may specify 2020 or earlier).

The WPS must list the essential variable ranges for each process in separate sections or clearly annotated fields. An Annex M WPS form applied to a combination process typically includes a separate process-entry row for SMAW and SAW, each with its own current range, wire/electrode class, and amperage limits. Do not compress both processes into a single WPS line — it invites audit failure.

PQR Test Plate Setup for the Combination

When qualifying by test, set up the PQR plate to replicate the production joint as closely as practical:

  1. Plate dimensions. Use the minimum plate thickness you intend to qualify, but not less than ¾ in (19 mm). AWS D1.1:2025 Table 6.6 sets thickness qualification ranges from the test plate thickness: a PQR on a 1 in plate qualifies production welds up to 2 in (double the plate thickness) for most processes.

  2. Joint geometry. Match the production groove — typically a single-V or double-V for SMAW root access, with a minimum root opening adequate for E7018 (1/16 to 3/32 in) and bevel angle wide enough for SAW fill drainage (22° to 30° half-angle is common for deep SAW passes).

  3. SMAW root sequence. Run the root pass and at minimum one additional SMAW hot pass before transitioning to SAW. The hot pass removes root pass slag and reduces hydrogen potential in the root zone.

  4. SAW fill and cap. Run to completion. Record wire feed speed, voltage, travel speed, and heat input on each pass or pass group per the PQR data requirements. Actual heat input in J/in or kJ/mm must be computed if CVN toughness supplementary essential variables apply (see Table 6.8).

  5. Mechanical tests. Cut tensile bars, bend specimens, and, if CVN is required, Charpy specimens from the completed test plate. Locations follow AWS D1.1:2025 Figure 6.9. If the plate has been SMAW-root-only for a significant depth, Charpy specimens must sample the HAZ of the SAW fill and cap zone as well — the root HAZ and the fill HAZ have different thermal cycles.

Record the PQR with separate process entries: list SMAW parameters (electrode size, AWS class, heat input or amperage/voltage/travel speed) and SAW parameters (wire diameter, wire class, flux class, current, voltage, travel speed) on separate lines. The qualified ranges then carry forward directly to the WPS.

Position Qualification Limits for the Combination

A frequently missed point: position qualifications earned by SMAW do not expand SAW's position limits. SAW under AWS D1.1:2025 Clause 5 is prequalified only in the 1G (flat) and 2G (horizontal) positions. A PQR run in the 3G position qualifies SMAW for all positions (1G, 2G, 3G, 4G) but qualifies SAW only for the positions demonstrated on the test plate, limited to those positions SAW can achieve in practice.

If the production joint requires overhead welding (4G or 4F), the SAW fill-and-cap option is not available; the WPS must use SMAW, GMAW-G, or FCAW-G for all overhead passes.

For in-position work — horizontal groove welds on column splices, flat groove welds on elevated girder assemblies using positioners — the SMAW root + SAW fill combination is well-suited and the qualification scope is straightforward.

Production Controls and Inspection Hold Points

Several production controls protect the combination weld from quality failure:

Root pass inspection before SAW. The CWI should verify root pass visual acceptance (MT or PT where required by the engineer) before the SAW head is set up. Once SAW is running, access to the root zone for rework is limited to back-gouging, which adds cost and time.

Preheat continuity. The combination WPS must maintain preheat through both process segments. Do not allow the joint to cool between the SMAW root and SAW setup. AWS D1.1:2025 Clause 5 and the PQR minimum preheat apply continuously.

SAW flux condition. Verify that flux is dry and properly reconditioned before the SAW fill begins. Wet flux is a significant hydrogen source and directly affects the HAZ of the fill and cap, even though the root was SMAW low-hydrogen.

Interpass temperature limit. SAW is a high-deposition, high-heat-input process. Interpass temperature can rise quickly on thick plates. Record interpass temperature at the start of each pass. If the WPS specifies a maximum interpass temperature (typically 550°F for structural carbon steel unless a higher limit is specifically qualified), enforce it.

WPS parameter compliance. Voltage and wire feed speed settings for SAW vary significantly with manufacturer's equipment. Confirm that the production SAW wire feed speed, voltage, and travel speed fall within the ranges recorded on the PQR and listed on the WPS before starting production.

Documentation and Audit Readiness

For an AISC-certified fabricator audit or third-party owner inspection, the combination WPS package must include:

  • The WPS form listing both process segments, with essential variable ranges for each process clearly separated
  • The PQR(s) supporting each process segment's essential variable ranges
  • Evidence of the CWI's review and approval signature
  • The welder qualification records (WPQ) confirming the production welders are qualified in both SMAW for the root and SAW for fill/cap

Welder qualification for SAW falls under the welding operator category — SAW is classified as machine welding. Verify that your welder qualification records distinguish between manual SMAW qualification and machine SAW operator qualification; they are separate documents under AWS D1.1:2025 Clause 6.

For further reading on how multiprocess WPS essential variables interact, see our article on AWS D1.1 multiprocess WPS essential variable scope, and for SMAW-specific low-hydrogen electrode documentation, see SMAW low-hydrogen E7018 WPS for structural steel. A full walk-through of SAW essential variable coverage is in SAW essential variables on a WPS under AWS D1.1.

If you're managing multiple combination WPS documents across a shop library, see how WPS software simplifies multiprocess tracking and audit packets versus spreadsheets that have no process-separation validation.