Visual Testing Procedure for Bolted and Welded Joints (AWS D1.1)

1. Scope

This procedure covers visual examination (VT) of high-strength bolted connections and welded joints in structural-steel buildings, bridges, and stadiums fabricated to AWS D1.1 Structural Welding Code — Steel and the RCSC Specification for Structural Joints Using High-Strength Bolts. Material class: ASTM A36, A572, A992 and other carbon and low-alloy structural steels. Fastener grades A325, F1852, A490, F2280 covered.

2. References

• AWS D1.1 — Structural Welding Code — Steel, Clause 8.9 (visual)
• RCSC Specification for Structural Joints Using High-Strength Bolts, current edition
• AISC 360 — Specification for Structural Steel Buildings
• AISC Code of Standard Practice
• ASNT SNT-TC-1A or AWS QC1 (CWI)

3. Personnel Qualification

VT examination of welded joints shall be performed by an AWS Certified Welding Inspector (CWI) or equivalent (CAWI, CWI, SCWI) holding a current certification. VT of bolted joints by a structural-steel inspector qualified per the project quality plan and AISC 360 §N3.

4. Equipment

• Visual aids — 6× to 10× hand-held magnifying lens; weld gauge set (Cambridge / Bridge / Fillet) calibrated; pit gauge; depth gauge; ruler / tape measure; mirror for inaccessible weld toes; flashlight (≥ 1000 lumens) for blind areas.
• Light meter — illumination at the surface to be examined: ≥ 1000 lux (≥ 100 fc) per AWS D1.1 §8.13.4.
• For bolted joints: calibrated DTI (Direct Tension Indicator) feeler gauge, calibrated load-indicating washer micrometer, or torque wrench per the RCSC pre-tensioning method specified.

5. Examination Conditions

• Lighting: ≥ 1000 lux at the examination surface. Where ambient is below this, supplemental task lighting required.
• Examiner eye-test: documented vision certification within 12 months — Snellen 20/30 or better (uncorrected or corrected), Jaeger J2 near-vision at 305 mm.
• Surface condition: cleaned of weld spatter, slag, and surface contamination that masks indications. Mill scale is acceptable; loose scale is not.
• Temperature: ambient. No examination during precipitation, on wet surfaces, or where condensation would impair visibility.

6. Welded Joint Examination

6.1 Coverage

Examination shall cover the entire weld length, both sides where accessible, and the adjacent 25 mm of base metal on each side of the weld toe.

6.2 Inspection Sequence

• Before welding (AWS D1.1 §8.9.1): joint preparation, fit-up, alignment, joint geometry per the WPS, pre-heat (where required), and material identification.
• During welding (§8.9.2): inter-pass temperature, slag removal between passes, weld bead profile per the WPS.
• After welding (§8.9.3): final weld profile, weld size, weld length, contour, surface condition, and any visual indication of defects.

6.3 Acceptance Criteria (AWS D1.1 §8.9.1 — Statically Loaded)

• Cracks: any crack is rejectable. Includes surface cracks, crater cracks, and toe cracks.
• Weld fusion: thorough fusion between weld metal and base metal and between layers of weld metal required.
• Crater cross-section: craters shall be filled.
• Weld profile: per Figure 5.4 — convexity within limits; weld toes shall blend smoothly into the base metal.
• Undercut: > 1 mm (1/32 in) deep — rejectable.
• Overlap: rejectable.
• Porosity (visible / piping): rejectable when the visible discontinuity (in a fillet weld or in any weld within 6 mm of the surface for a CJP groove weld in tension) exceeds limits of §8.9.1.5:
  • Pipe porosity > 1 mm in a 25 mm length OR aggregate > 10 mm in 100 mm.
• Weld size: fillet shall not be less than the specified size for more than 10% of the weld length per §8.9.1.

For cyclically loaded (fatigue-critical) weldments per §8.9.2, the limits tighten — no visible cracks, no porosity, undercut limited to 0.25 mm where transverse to the principal stress, and weld-toe-blending verified.

7. Bolted Joint Examination

7.1 Snug-Tight Condition (RCSC §8.1)

• Bolt heads and nut faces firmly seated against the joint surfaces.
• Sufficient pre-installation visible to indicate the bolt has been driven home — no gaps under the head or washer.

7.2 Pre-Tensioned Bolts (RCSC §8.2)

Verified by the method specified in the contract — one of:

• Turn-of-Nut method (RCSC §8.2.1): snug-tight, then specified additional rotation per RCSC Table 8.1.
• Calibrated Wrench (RCSC §8.2.2): torque applied to achieve at least the specified pretension, verified by Skidmore-Wilhelm calibration each shift.
• Twist-off-type tension-control bolts (TC bolts, RCSC §8.2.3): spline shear-off verified visually.
• Direct Tension Indicator (DTI) washers (RCSC §8.2.4): gap at the prescribed dimensions per the DTI manufacturer's calibrated feeler gauge.

7.3 Pre-Installation Verification

For pre-tensioned and slip-critical joints, 3 bolts from each combination of bolt, nut, and washer verified by Skidmore-Wilhelm load cell or DTI calibration before installation. Records retained per RCSC §8.2.4.

8. Reporting

Per AWS D1.1 §8.13.5 and the project quality plan — minimum: project, drawing, member ID, weld or bolt connection ID, weld procedure / bolt type, examiner name and AWS CWI certification, lighting verified (lux value), date / time, sketch with location and disposition of every recordable indication, repair and re-examination record where applicable, and CWI signature.

9. Safety

PPE per project — minimum hard hat, eye protection, hearing protection where applicable, fall-arrest for elevated work, and high-visibility apparel on active construction sites. Hot-work proximity restrictions where grinding or cutting is in progress.

This procedure is a published reference. Production use requires Engineer-of-Record approval and project quality plan alignment. Generate a project-specific VT plan including the exact bolting method, fatigue-class limits, and acceptance gauges at the free AI Procedure Generator.