Lifting lugs, pad eyes, and rigging attachments are among the most commonly under-documented welds in structural fabrication. Shops weld hundreds of them—on columns, girders, plate assemblies, and prefabricated modules—and treat them as non-structural hardware because they come off after the iron is set. That assumption is wrong, and it becomes a problem during third-party audit, owner inspection, or an incident investigation.

AWS D1.1 defines its scope broadly: it covers structural welds in steel. A fillet weld attaching a lifting lug to an A572 Grade 50 wide-flange column is a structural weld. The fact that the lug is temporary and will be removed after erection does not move it outside the code's scope. The weld exists, it carries load, and it must be performed in accordance with a qualified WPS by a qualified welder.

What AWS D1.1 Actually Requires

AWS D1.1 requires that all welding performed under the code be done in accordance with a WPS. The WPS must be either prequalified (meeting the conditions of the prequalification clause) or tested (qualified by a PQR). It must be available at the work site before welding begins, and the CWI has authority to halt welding if no applicable WPS is present.

For lifting lugs, the WPS must address:

  • Welding process — SMAW, FCAW-G, or GMAW (the most common for lug attachment)
  • Base metals — the lug plate material and the structural member material, both by ASTM designation and minimum yield
  • Joint type — most lugs are fillet-welded (single or double fillet); some are full-penetration groove-welded for higher loads or demand-critical applications
  • Position — typically 1F or 2F for shop, 1F through 4F for field erection work
  • Preheat and interpass temperatures — based on carbon equivalent of both the lug and the parent member
  • Filler metal — classified per the applicable AWS A5-series standard, with H-suffix if required
  • Pass sequence and minimum/maximum fillet weld size

The most common shortcut fabricators take is using a verbal instruction or a generic shop weld detail sheet instead of a qualified WPS. Neither satisfies the code.

Prequalified WPS vs. Tested Procedure

For most lifting lug applications, a prequalified WPS is achievable and cost-effective. Prequalification is available for SMAW, FCAW-G, GMAW (spray and pulse), SAW, and GTAW on base metals listed in the D1.1 prequalified base metal table.

Prequalification requires:

  1. The base metals of both the lug and the structural member must both be on the prequalified list
  2. The joint details (root opening, angle, backing if applicable) must conform to the prequalified joint geometry tables
  3. Process-specific parameters (amperage, voltage, travel speed, preheat, filler metal) must fall within the prequalified ranges

Prequalification becomes unavailable when:

  • The lug or parent material is a grade not on the prequalified list
  • The joint is a CJP groove that is not a standard prequalified detail
  • The process is ESW or EGW, which are excluded from prequalification

When prequalification doesn't apply, a tested WPS supported by a PQR is required. For fillet weld lugs, the PQR only requires a fillet weld break or macro test—no tensile or guided bend tests—which keeps the qualification cost modest. See how to qualify a welding procedure for a walkthrough of the PQR test matrix.

Base Metal Matching and Filler Metal Selection

Lifting lugs are almost always fabricated from A36 plate because it is cheap and available. The structural member they are welded to is often A572 Grade 50, A913, or A992. This creates a dissimilar base metal combination that the WPS must explicitly address.

AWS D1.1 permits prequalified welding between different base metal groups as long as both are on the prequalified list and the filler metal meets the higher minimum tensile requirement. The filler metal classification must match or exceed the mechanical properties of the lower-strength base metal.

For an A36 lug welded to an A572 Grade 50 member, an E70-series SMAW electrode or ER70S-3/ER70S-6 GMAW wire satisfies the requirement. The filler's 70 ksi minimum tensile strength exceeds A36's specified tensile range and is appropriate for the A572 Grade 50 member. The WPS should call out both base metals and identify the filler metal classification explicitly—"A36 lug to A572 Gr. 50 member, E7018-H4" leaves no ambiguity for the inspector or auditor.

Preheat for Lug-to-Member Welds

Preheat requirements are based on base metal type, carbon equivalent, and material thickness. For a lifting lug application:

  • Lug plate is often thin (3/8 to 1 inch), so its own preheat requirement may be low
  • Structural member flange or web can be significantly thicker and trigger a higher preheat temperature
  • The governing preheat is the higher of the two, determined separately for each material

A common mistake is calculating preheat only for the lug plate thickness and ignoring the parent member thickness. This can result in inadequate preheat on the structural member, increasing hydrogen-assisted cracking risk in the heat-affected zone—particularly relevant when an E7018-H8 electrode is used on a high-CE A572 or A913 member. See carbon equivalent and preheat calculations under AWS D1.1 for the calculation procedure.

When ambient temperature drops below 32°F, minimum preheat requirements increase regardless of material thickness. Field erection of lifting lug attachments in winter requires active heating and temperature verification before striking an arc—this must be noted in the WPS and enforced by the field inspector.

Fillet Weld Size and Inspection

The fillet weld size for a lifting lug must be calculated by the engineer based on the rated lifting load, lug geometry, and load angle. The WPS documents the specified minimum and maximum fillet weld size. The CWI verifies during and after welding using calibrated fillet weld gauges.

For any single or double-fillet lug attachment, the inspector should verify:

  • Minimum throat dimension (effective throat = 0.707 × leg size for equal-leg fillets)
  • Length of weld on each side of the lug
  • Visual acceptance criteria per AWS D1.1: undercut ≤ 1/32 in., no cracks, no unfilled craters at weld ends
  • End returns at corners if specified on the detail drawing

Acceptance criteria follow the standard visual inspection requirements of AWS D1.1. If MT or PT is specified—which is common for lugs on primary structural members or for owner specifications requiring NDE on all attachment welds—acceptance criteria are per the applicable NDE standard referenced in the project specification. See magnetic particle testing for structural welds for MT procedure and documentation requirements.

After Lug Removal: The Often-Forgotten Step

When a temporary lifting lug is removed after erection, the removal operation also requires a documented procedure. The common removal sequence is:

  1. Air carbon arc gouging or thermal cutting to sever the lug, leaving a small amount of weld metal on the structural surface
  2. Grinding flush to the structural base metal surface
  3. Visual and MT inspection of the finished surface and immediate HAZ

The cutting or gouging and final finish grinding should be covered by a written procedure—either a formal WPS or a specific cutting procedure included in the project quality plan. The finished removal area must meet visual acceptance criteria, and MT inspection is standard practice on primary structural members.

If the lug was on a tension flange, a demand-critical member, or a member in a cyclically loaded structure, treat the removal scar as a potential fatigue initiation site. Check the finished surface for residual undercut, notches, or concavity that could act as stress risers under repeated loading. See the temporary welds and strongback attachment requirements article for related documentation requirements.

Documentation for the Audit Packet

A complete lifting lug weld record includes:

  • WPS reference number and revision tied to the weld map or weld traveler
  • Welder ID and WPQ certification for the applicable process and position
  • Pre-weld inspection report: preheat verified, fit-up accepted, filler metal identified by heat/lot number
  • Post-weld inspection report: fillet weld gauge measurements, visual acceptance, NDE results if required
  • Lug removal inspection report: finished surface condition, MT results

When auditors review a project weld package, lifting lug records are among the first they look for—precisely because they are routinely missing. A weld map that traces every groove weld to a WPS reference but leaves lifting lugs untracked is a finding waiting to happen.

Retain lifting lug records for the same period as other structural weld records for the project. AWS D1.1 does not specify a shorter retention period for temporary attachment welds. See WPS and PQR record retention requirements for the general retention framework.

Common Audit Findings for Lifting Lug Welds

Third-party auditors and owner representatives consistently find the same deficiencies in lifting lug weld documentation:

  • No WPS cited: The weld map or traveler shows lifting lug locations with no WPS reference—often because the shop assumed lug welds were exempt
  • Welder not qualified for position: A welder qualified 1G/2G completes overhead (4F) lug attachments during field erection without the required position coverage
  • Lug material not identified: The WPS references A36-to-A572 but no CMTR or material trace exists for the lug plate
  • Removal scar not inspected: The post-erection survey shows lugs removed and areas ground flush with no MT record
  • Preheat not verified for member thickness: Preheat records reference lug thickness, not the heavier parent member

Each of these findings can trigger a corrective action request, delay project closeout, or—in a worst case—require after-the-fact qualification testing to demonstrate the weld is acceptable.

Managing WPS traceability across hundreds of lifting lug welds on a large project requires a system, not a spreadsheet. For fabrication and erection shops building that infrastructure, our pricing page shows software plans that include WPS-linked weld registers and NDE record storage.