Shear studs are often treated as a commodity item on a structural steel project — order the studs, stud-weld them to the beam, done. But AWS D1.1:2025 Clause 7 establishes a formal qualification and inspection framework for stud welding that catches the same category of quality failures that the WPS/PQR system catches for conventional groove and fillet welding. A QC manager who treats studs as a "no paperwork" item is setting up for an RFI at the worst possible time.
Rule library based on AWS D1.1:2025; verify against your governing edition (the AHJ or contract may specify 2020 or earlier).
What Clause 7 Governs
AWS D1.1:2025 Clause 7 ("Stud Application") covers the design, qualification, and inspection of headed studs, deformed bar anchors, and other shear connectors welded to structural steel by arc stud welding (ASW) or capacitor discharge stud welding (CDSS). The typical application is composite beam construction — stud shear connectors welded through deck or directly to the top flange — but Clause 7 also covers moment frame base plates, anchor rod attachments, and other structural stud applications.
The clause establishes requirements for:
- Stud materials and dimensions
- Welding procedure qualification (pre-production testing)
- Production welding controls
- Visual acceptance criteria
- Repair of rejected studs
Arc Stud Welding vs. Capacitor Discharge
The two processes covered by Clause 7 have different qualification paths.
Arc stud welding (ASW) is the dominant process for composite construction. A typical 3/4-in. (19 mm) headed shear connector is arc-welded using a stud gun with a ceramic ferrule. The ferrule shapes the weld flash and protects the arc. ASW requires a flux load in the stud tip and typically a power source capable of high amperage output over a short duration. The resulting fillet of weld flash (the 360° collar around the stud base) is one of the primary visual acceptance criteria.
Capacitor discharge stud welding (CDSS) stores energy in capacitors and discharges it nearly instantaneously — the entire weld cycle is measured in milliseconds. The very short arc time means minimal heat input, virtually no HAZ, and no need for a ferrule. CDSS is used for smaller studs (typically ≤ 1/2 in. diameter) on thinner material. It cannot produce the same weld size as ASW for large-diameter studs.
Different welding procedures are required for each process — an ASW procedure does not qualify CDSS and vice versa.
Stud Welding Procedure Specification
Just as groove and fillet welds require a WPS, stud welding requires a written procedure that documents the essential production parameters. The stud WPS must include:
- Stud manufacturer and type (e.g., Nelson Type B, TRW Nelson, or equivalent)
- Stud material and base diameter (the shank diameter, not the head)
- Flux type and load (built into the stud tip for most ASW studs)
- Ferrule type — ceramic size matched to stud diameter
- Power source type and settings — weld current, weld time (lift height and plunge are also relevant for ASW)
- Base metal type and condition — coating, paint, galvanizing, or bare steel each require attention
- Position — flat (1F) is the common production position; overhead or inclined positions require specific documentation
- Shielding — most ASW work is unshielded, but specific procedures may call for shielding gas
When studs are welded through steel deck to the beam flange (the common composite deck application), the procedure must be qualified with through-deck welding. The deck type, profile height, and number of thicknesses affect weld quality significantly. A procedure qualified on bare steel does not automatically qualify through-deck conditions.
Pre-Production Qualification Testing
Before production stud welding begins on a project — or when any essential parameter changes — AWS D1.1:2025 Clause 7 requires pre-production testing. The minimum requirement is:
Two test studs welded to a test piece of representative base metal using the same equipment settings, stud type, and welding position to be used in production. Both test studs must pass the bend test.
Bend test procedure:
- The stud is struck or pressed to bend it 30° from its original axis using a ring, tube, or equivalent.
- After bending to 30°, the stud must not fracture — neither the weld nor the stud shank should crack.
- There is no requirement to bend the stud back; the test is pass/fail at the bent position.
Torque test: An alternative for studs with published torque qualification values. A calibrated torque wrench is applied to the stud; the stud must sustain the specified torque without weld failure.
The test piece should replicate the production condition as closely as practical — same base metal specification and thickness, same paint or primer condition if production studs will go through coated steel, same deck profile and thickness for through-deck work.
Production Visual Acceptance Criteria
Every welded stud in production must be visually inspected. AWS D1.1:2025 Clause 7 acceptance criteria for arc-welded studs include:
360° flash collar: The weld flash must form a full 360° collar around the stud base. A complete, uniform collar is the primary indicator that fusion was achieved around the full perimeter. Missing flash over any arc of the circumference is a reject.
No cracks: The weld area and stud shank immediately above the weld must be free of cracks.
No porosity or undercut that would impair the structural function of the stud.
Stud height and plumb: After welding, the stud height (measured from base metal to the underside of the head) must be within the tolerance stated on the design drawing or in the project specification. The stud must be reasonably plumb — AWS D1.1 allows up to 5° from perpendicular.
Base metal condition: The area adjacent to the stud base must be free of undercut, cracks, or other discontinuities beyond allowable limits.
Repair of Rejected Studs
A stud that fails the bend test during pre-production, or fails visual inspection during production, may not simply be re-welded in the same location. AWS D1.1:2025 Clause 7 specifies repair options:
- Rejected pre-production studs: Adjust the welding procedure and re-test. Do not proceed to production until two consecutive studs pass.
- Production rejects: A failed stud is either cut off and a replacement stud welded adjacent to it (clear of the damaged zone), or the area is repaired by the CWI-approved method. Cut stud remnants must be removed flush with the base metal surface; the weld scar may be ground smooth.
Stud removal is done by striking with a sledgehammer or using a cutting tool. If the stud base cannot be removed cleanly, the contractor must submit a repair procedure for engineer review.
CWI Inspection Checkpoints
A CWI performing receiving, in-process, and final inspection for stud welding should verify:
- Pre-production test performed and documented — two test studs bent 30° before production begins (or any time essential variables change).
- Stud WPS on hand — matching the stud type, diameter, and base material being used.
- Equipment settings verified — weld current and weld time logged before production; not just set once and forgotten.
- Ferrule condition — ceramic ferrules that are cracked or wet produce incomplete collars. Ferrules should be inspected and kept dry.
- Base metal cleanliness — scale, heavy rust, paint, primer, or moisture at the weld location are each cause for rejection before welding.
- 360° flash check — walk the beam and check each stud after ferrule removal. Tap the ferrule off with a hammer; do not knock studs sideways.
- Touch-up documentation — any rejected or repaired stud must be noted on the inspection record and the repair procedure approved.
For more background on WPS and PQR documentation structures, see WPS vs. PQR vs. WPQ and WPS essential variables for SMAW, GMAW, and FCAW. If your project scope includes AISC-certified fabrication, the stud qualification records are part of the audit-ready package — see AISC fab certification audit readiness.
Summary
Stud welding under AWS D1.1:2025 Clause 7 is not an informal process — it requires a documented procedure, pre-production qualification testing, and systematic production inspection. The bend test is simple and fast; running it before production starts costs 10 minutes and prevents rework that could affect composite beam design loads. A qualified stud WPS and inspection log belong in every project audit package alongside the groove and fillet weld procedures. See our welding procedure platform for integrated stud WPS documentation tools.