AWS D1.1:2025 Quick Reference
AWS D1.1:2025 covers welded structural steel up to 100 ksi yield strength and 1/8-inch minimum thickness. Its 11 clauses cover scope, references, terms, design, prequalification, qualification, fabrication, inspection, tubular work, repair, and stud welding. Most projects use Clause 5 prequalified WPSs; non-standard joints need Clause 6 PQR testing.
Decision path: Use this quick reference to choose the governing D1.1 lane, then jump to the exact field check.
What AWS D1.1:2025 Covers
AWS D1.1:2025 Structural Welding Code — Steel applies to the design, fabrication, and inspection of welded structural steel construction. The code's scope per Clause 1.1 covers carbon and low-alloy steels with a minimum specified yield strength up to 100 ksi (690 MPa) and base metal thickness 1/8 inch (3 mm) or greater.
Materials and structures NOT covered by D1.1: sheet steel under 1/8 inch (use D1.3), stainless steel (use D1.6), aluminum (use D1.2), reinforcing bar (use D1.4), bridges with cyclic loading or fracture-critical members (use D1.5). Tubular structures are covered in Clause 9 of D1.1 with cross-references to the main body. Stud welding is covered in Clause 11.
Welding processes covered: Shielded Metal Arc (SMAW), Gas Metal Arc (GMAW), Flux-Cored Arc (FCAW gas-shielded and self-shielded), Submerged Arc (SAW), Gas Tungsten Arc (GTAW), and Electroslag/Electrogas (ESW/EGW). Prequalified-WPS essential variables are in Table 5.5. Table 6.6 identifies PQR essential-variable changes requiring WPS requalification for SMAW, SAW, GMAW, FCAW, and GTAW. Table 6.7 identifies them for ESW/EGW.
Per AWS D1.1:2025 Clause 1.1.1: “This code contains the requirements for fabricating and erecting welded steel structures. When this code is stipulated in contract documents, conformance with all provisions of the code shall be required, except for those provisions that the Engineer or contract documents specifically modifies or exempts.”
— AWS D1.1/D1.1M:2025, Structural Welding Code — SteelThe 11 Clauses of AWS D1.1:2025
| Clause | Title | Covers |
|---|---|---|
| Clause 1 | General Requirements | Scope, applicability, units, base metals covered |
| Clause 2 | Normative References | Referenced standards (AWS A2.4, A3.0, A5 series, ASTM) |
| Clause 3 | Terms and Definitions | Welding terminology defined per AWS A3.0 |
| Clause 4 | Design | Allowable stresses, joint design, fillet/groove sizing, fatigue |
| Clause 5 | Prequalification of WPSs | Joint details, materials, parameters accepted by reference (no testing) |
| Clause 6 | Qualification | PQR procedure, qualification testing, welder/operator qualification |
| Clause 7 | Fabrication | Cutting, fit-up, preheat application, welder workmanship |
| Clause 8 | Inspection | Inspector qualifications (CWI per QC1), VT, NDT, acceptance criteria |
| Clause 9 | Tubular Structures | Specific provisions for hollow section connections (HSS, pipe) |
| Clause 10 | Strengthening and Repair | Existing structure modifications, weld repair procedures |
| Clause 11 | Stud Welding | Drawn-arc and capacitor-discharge stud welding requirements |
The lifecycle order — design (4), prequalification or qualification (5/6), fabrication (7), inspection (8) — reflects the order operations are typically performed on a project. Specialty clauses 9, 10, and 11 augment the main body for specific construction types.
Most-Cited Tables in D1.1:2025
Table 5.7 — Filler Metal Requirements (Prequalified)
Table 5.7 matches the applicable Table 5.6 base-metal group to allowable filler-metal classifications and strength conditions. Use the exact Group I through V pairing shown in the table; Category A through G belongs to the separate Table 5.11 preheat lookup.
Table 5.11 — Minimum Preheat and Interpass Temperature (Prequalified)
Table 5.11 is the most-referenced table in D1.1 for shop floor work. It specifies minimum preheat and interpass temperatures by listed steel specification, welding process and electrode hydrogen designation, and thickness of the thickest part at the point of welding. The Table 5.6 group is not its lookup key. Clause 5.7.1 requires Table 5.11 to be used for the steels listed there. Use the preheat calculator for the exact row and thickness band.
Table 7.7 — Minimum Fillet Weld Size
Table 7.7 specifies minimum fillet weld leg size based on base metal thickness:
| Base Metal Thickness (T) | Minimum Fillet Leg |
|---|---|
| T ≤ 1/4 inch [T ≤ 6 mm] | 1/8 inch (3 mm) |
| 1/4 < T ≤ 1/2 inch [6 < T ≤ 12 mm] | 3/16 inch (5 mm) |
| 1/2 < T ≤ 3/4 inch [12 < T ≤ 20 mm] | 1/4 inch (6 mm) |
| 3/4 inch < T [20 mm < T] | 5/16 inch (8 mm) |
Per Footnote A, T is the thicker part for non-low-hydrogen single-pass; T is the thinner part for low-hydrogen processes. Per Footnote C, 3/16 inch [5 mm] is the minimum for cyclically loaded structures; it raises the first-row 1/8 inch value and does not cap thicker-material rows.
Table 8.1 — Visual Inspection Acceptance Criteria
Table 8.1 specifies visual acceptance criteria for fillet, CJP, and PJP welds, separated by static vs cyclic loading. Cracks of any size are unacceptable in both load conditions. Undercut limits are 1/32 inch maximum for static, 1/100 inch for cyclic per direction-of-stress rules. Piping porosity limits depend on connection and weld type: sum limits count visible pores 1/32 inch or greater in diameter, and the frequency limits allow a maximum pore diameter of 3/32 inch. Per §8.9, all visual inspection shall be performed by a qualified inspector per Clause 8.1.4 — typically a CWI per AWS QC1.
Base Metal Groups (Table 5.6)
D1.1:2025 uses the steel Group I–V system in Table 5.6 (per § 5.3 Base Metal) for prequalified base metals. The groups are not the same as the Category A through G rows used inside Table 5.11 for preheat, and they are not the fatigue stress categories A through F in Table 4.5.
Each group has matching filler-metal options in Table 5.7. Table 5.11 is a separate lookup by listed steel specification, welding process and electrode hydrogen designation, and thickness; the Table 5.6 group is not its key.
Prequalified vs Qualified WPS — Decision Logic
Per Clause 5, a prequalified WPS uses a joint, base metal, filler metal, and parameters that the code accepts as qualified by reference. To use a prequalified WPS, ALL of the following must hold:
- Joint matches Figures 5.1 through 5.10 (over 100 prequalified joint details)
- Base metal is in Table 5.6 (one of the approved Groups I-V)
- Filler metal matches Table 5.7 for the base metal group
- Preheat meets the Table 5.11 minimum for the listed steel specification, welding process and electrode hydrogen designation, and thickness — not the Table 5.6 group
- All essential variables stay within Table 5.5 ranges per
§5.5
If any prequalified condition cannot be met, a qualified WPS per Clause 6 is required. The contractor performs a Procedure Qualification Record (PQR) — weld a test coupon to the proposed parameters, then perform qualification testing per Tables 6.2 through 6.5, as applicable to the joint type. The PQR validates the specific parameter combination, and the resulting WPS is qualified for production use only within the variables and ranges actually qualified by the PQR under Clause 6.
Field tip: Always check prequalification first. PQR testing typically costs $2,000-$5,000 per procedure. If your joint is in Figure 5.1 to 5.10 and your steel is in Table 5.6, prequalification is the cheaper, faster path. Groups IV and V are listed in Table 5.6 and may use a prequalified WPS when every Clause 5 requirement is met. Non-prequalified joints and base metals not listed in Table 5.6 require Clause 6 qualification.
— CWI shop floor observation, structural fabricator, 2026Inspection Scope (Clause 8)
Per Clause 8, AWS D1.1:2025 inspection requirements cover three layers: visual inspection (VT), nondestructive testing (NDT), and inspector qualification.
Per §8.9, all welds shall be visually inspected. Visual inspection is performed by personnel meeting the qualification requirements of §8.1.4 — typically a Certified Welding Inspector (CWI) per AWS QC1, or an equivalent inspector qualification. VT is performed before any volumetric NDT per §8.13.
Per §8.13 and §8.14, NDT methods include radiographic testing (RT), ultrasonic testing (UT), magnetic particle testing (MT), and penetrant testing (PT). The contract documents specify which welds require NDT and which method. CJP welds in tension typically require either RT or UT per §8.14.5. Statically loaded structures may require less NDT than cyclically loaded.
Acceptance criteria per Table 8.1 for VT, Table 8.2 for tension-loaded welds (RT/UT), and Table 8.3 for compression-loaded welds. The CWI's authority and responsibilities are defined in §8.1 through §8.4 — the inspector verifies WPS, monitors fit-up and welding, performs VT, witnesses or reviews NDT, and signs off on weld acceptance.
How to Cite AWS D1.1 in Procedures and Reports
Formal references: AWS D1.1/D1.1M:2025 Structural Welding Code — Steel, American Welding Society, Miami, FL. The /D1.1M suffix indicates the metric companion document — for SI unit projects use D1.1M:2025.
Within procedures, WPS forms, and inspection reports, the short form AWS D1.1:2025 is acceptable along with the specific clause, table, or figure being referenced. Examples of acceptable inline citations:
per AWS D1.1:2025 Table 5.11— preheat referenceper AWS D1.1:2025 §8.9— inspection scope referenceper AWS D1.1:2025 Clause 6.2.1— PQR testing referenceper AWS D1.1:2025 Figure 5.4— prequalified joint reference
The 2025 edition is the current edition as of April 2026 and supersedes D1.1:2020. Drawings and contracts that reference “AWS D1.1” without an edition default to the latest edition unless explicitly fixed (uncommon and requires explicit owner agreement). When a project transitions from one edition to the next, all related WPSs, PQRs, and inspector qualifications should be reviewed for any code changes that affect the work — see the dedicated AWS D1.1:2025 changes guide for the most-impactful 2025 updates.