Does AWS D1.1:2025 require material test reports on file?

AWS D1.1:2025 requires that base metals conform to the applicable ASTM or other listed specification. The MTR is the primary evidence of conformance. Most engineer-of-record specifications and AISC Certification programs require the MTR to be on file and traceable to the specific heat and lot of material actually used.

What ASTM information must an MTR contain to satisfy a structural WPS?

A compliant MTR must identify the heat number, specification designation (e.g., ASTM A36, A572 Gr.50), chemistry (carbon equivalent and any supplemental chemistry), mechanical test results (yield, tensile, elongation), and the certifying mill's signature. The heat number must match the mill stencil on the material.

Can you weld prequalified joints on unlisted base metals?

No. AWS D1.1:2025 prequalified status applies only to base metals explicitly listed in Table 6.6 (as group designations) or the prequalified base metal tables. If the MTR shows a spec not on the AWS list, the WPS must be procedure-qualified — not prequalified.

What should a CWI do when the MTR is missing or the heat number doesn't match?

Stop the work on that heat lot until the MTR is located or the material is tested. Welding non-conforming or untracked steel to a structural WPS is a code violation. Document the hold in the inspection record and notify the QC manager.

Material Test Reports and WPS Base Metal Traceability

MTRs connect the steel you're welding to the base metal spec on your WPS. Here's what CWIs must verify before striking an arc on structural steel.

The MTR is the birth certificate of the steel you are welding. Without it, you cannot confirm that the base metal on the shop floor matches the base metal specification written into your WPS — and a WPS that does not match the actual material is not a valid procedure. Every CWI who has walked into a fabrication shop mid-project has seen steel stacked without MTRs in reach. Making that a correctable nuisance rather than a costly shutdown requires understanding what the MTR must contain, how it connects to the WPS, and what the inspection hold points are.

Why the MTR-to-WPS connection matters

AWS D1.1:2025 permits two paths for WPS qualification: prequalified and procedure-qualified. Both paths start with the same requirement — the base metal must be an acceptable specification.

For prequalified WPS procedures, AWS D1.1 defines which base metals are permitted directly. If your WPS says SMAW on A36, the MTR must confirm the material is ASTM A36. If the MTR shows A1011 Grade 50 sheet steel, that material may not qualify on the same prequalified WPS. The wrong material means the wrong minimum preheat, the wrong filler metal group, and possibly a joint type that is not prequalified for that base metal.

For procedure-qualified WPS procedures, the PQR records the actual base metal specification tested. When you run production welds, the production base metal must fall within the qualified base metal group. The MTR is the document that proves it does.

What a complete MTR must show

A structurally adequate MTR covers five areas:

Identity

Mill name and location
Heat number (unique to the melt)
Lot or coil number when applicable
ASTM or other specification designation (e.g., ASTM A572/A572M Grade 50)
Thickness, width, and product form (plate, W-shape, HSS)

Chemistry
The certified ladle analysis lists every required element plus any supplemental elements. For high-strength steels, carbon equivalent (CE) is often calculated from the ladle chemistry using the IIW formula. That CE number feeds directly into the preheat calculation on your WPS.

Mechanical properties
Tensile strength, yield strength, and percent elongation from the tension test. For fracture-critical members that invoke Table 6.8 supplementary essential variables, Charpy V-notch (CVN) energy values at the required test temperature must also appear.

Heat treatment record (when applicable)
A913 Grade 65 and other thermomechanically treated steels include the treatment condition (TMCP or QT). That condition is an essential variable under Table 6.6 — a different heat treatment on the same base metal can trigger requalification.

Certification statement
A physically or digitally signed statement that the material meets the cited specification, from the certifying laboratory or the producing mill. A photocopy of a photocopy that cannot be traced to a specific heat number is not adequate for audit purposes.

Tracing the MTR to the material in the shop

An MTR that sits in a binder on the QC manager's desk but cannot be connected to the steel on the fit-up table is not serving its function. The traceability chain runs from the MTR to the physical material through the heat number.

Mill stencil check. Every structural shape and plate product has the specification designation, grade, and heat number stenciled at the mill. When material arrives, receiving inspection should verify the stencil matches what is on the purchase order and MTR. Missing stencils should be flagged before the material enters the cutting queue.

Cut list tracking. When the shop cuts pieces from a plate or shape, the heat number must follow the cut pieces. Some shops stencil the heat number on every piece; others maintain a cut log that links each piece number to the original heat. Either method is acceptable as long as the trail is unbroken from MTR to finished weld joint.

Weld map integration. A weld map ties each joint on the fabricated assembly to the base metal heat numbers, the applicable WPS number, and the welder ID. When the AISC auditor or the engineer's third-party inspector walks the floor, the weld map should answer, for any joint: what is the base metal, what was the procedure, and who welded it. For shops managing MTR traceability in a spreadsheet, maintaining this linkage is error-prone. Software that ties the WPS directly to the material heat number and generates the weld map automatically removes that error source.

Common deficiencies found during inspections

Mismatched heat number. The MTR in the file is for heat 72A143; the stencil on the material reads 72A148. Either a different heat was substituted without a new MTR, or the MTR filing was wrong. Either way, it is a nonconformance.

Specification not on the WPS. The WPS qualifies ASTM A572 Grade 50. The MTR for the column material shows ASTM A992 Grade 50. These are not the same specification. A992 has tighter chemistry controls (Fy/Fu ratio cap, Mn:C ratio) and is listed separately in AWS D1.1. The CWI must confirm the WPS covers A992 or that A992 and A572 Gr.50 fall within the same qualified base metal group under the PQR.

Supplemental chemistry not reported. A572 plate produced to supplemental requirement S5 (fracture-critical) must include CVN test results. When the job specification requires fracture toughness, an MTR that shows only mechanical properties without CVN data is incomplete.

TMCP or QT condition not documented. High-performance steels like A913 are produced by thermomechanical controlled processing. If the WPS and PQR were qualified on TMCP-conditioned material and the MTR for production steel shows QT condition, that is an essential variable change under Table 6.6 that requires requalification.

The CWI inspection hold sequence

Before welding begins on any structural joint, the CWI should verify in order:

MTR in hand — is the MTR present for this heat lot?
Heat number match — does the MTR heat number match the stencil on the material?
Specification match — does the MTR specification match the base metal listed on the WPS?
Grade match — does the grade (yield strength tier, supplemental requirements) align with the WPS and the project specification?
CVN coverage — if the joint is fracture-critical or the job spec invokes Table 6.8, does the MTR include CVN results at the required test temperature?

Any "no" answer is a hold point. Document the hold, identify the resolution path, and do not authorize welding until the discrepancy is closed in writing.

Keeping MTR records for the life of the structure

AWS D1.1:2025 does not specify a document retention period, but most project specifications, AISC Certification requirements, and state DOT programs require MTRs to be retained for the life of the structure or a minimum of ten years. Digital retention with indexed search by heat number and project removes the end-of-project scramble and protects the fabricator when questions arise during structure service.

Shops running WPS software can store the MTR reference alongside the WPS and weld map record for each joint, creating a single audit-ready package. See what an audit-ready WPS package contains and how weld map traceability works in production for more detail on building that package.

Rule library based on AWS D1.1:2025; verify against your governing edition.

If your shop tracks MTRs in spreadsheets and the traceability chain breaks when a heat gets split across jobs, WPS software with built-in material heat number tracking removes that manual link and keeps the audit trail intact from MTR receipt to final inspection sign-off.