Steel Plate Traceability and Mill Test Certificates
A mill test certificate (MTC) records the test results for the material it covers. Traceability is the documented link between that certificate, the plate received by the shop, and the component made from it. For a bridge girder, the link matters most after cutting, when the web and flange pieces may no longer carry the mill's original markings.
Define how far traceability needs to go
The drawings, purchase specification and inspection plan should establish the required level. A contract may call for material identification by grade, traceability by lot, or a link from each piece mark back to a particular heat. A record system designed for grade identification cannot establish a piece's heat after the fact. The AISC fabrication FAQ explains these distinctions. The applicable project documents determine what the supplier must provide.
Follow the record from plate to girder
| Stage | What to check |
|---|---|
| Goods receipt | Plate marking, material grade, thickness and the matching MTC reference |
| Cutting | Nesting or cut list that links the parent plate to the cut pieces, including usable remnants where required |
| Assembly | Piece marks that connect the web, flanges and stiffeners to the girder's assembly record |
| Inspection and release | A traceability register or equivalent record that lets the reviewer find the relevant certificate for a selected piece |
For example, ask the shop to select a flange from a representative girder and work back from its piece mark to the plate record and certificate. Then trace a second piece forward from receipt to assembly. These two checks reveal whether the records can be used in both directions during inspection.
Resolve gaps before the next inspection stage
Typical gaps include a missing mark after cutting, a remnant reused on another job, or a certificate whose identifiers do not match the plate. Ask how the shop separates affected material, records discrepancies and obtains any required disposition before that material is used. Agree on who reviews the register and which records go in the final manufacturing dossier.
See our steel fabrication quality control guide for the wider inspection workflow. If your package has piece-level traceability or buyer witness points, send the material specification and inspection plan with the enquiry.
About Kothari Chemicals (Engineering Division)
The Kothari Chemicals (Engineering Division) at Kothari Chemicals Engineering Division brings decades of combined experience in steel fabrication, quality assurance, and project management. We're committed to sharing knowledge that helps our industry grow.
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