Documents & records
Mill certificate
A mill certificate is the document a steel or metal producer issues to certify what a given lot actually is (its chemical composition and mechanical test results), traceable to the heat it was poured from. For structural steel, rebar, anchor bolts and similar products, it is the paper that proves the material meets the specified grade rather than just being labeled as that grade. It arrives with the delivery and gets matched against the approved submittal at receiving.
Run it with the Photo Gate
Structural steel inspection checklist
12 items · 27 photos required
Why it matters
The grade of a structural material is not something you can confirm by looking at it, so the mill certificate is the evidence that the steel in the frame is the steel the engineer designed for. Without it, a substitution to a lower grade is invisible until something is tested or fails, which is why specs on structural work require the certificate before the material is installed.
It is also a traceability link. If a question comes up later about a member or a bolt, the mill certificate ties that piece back to a heat and its test results: the chain a record needs to answer where the material came from and what it was.
How it shows up on site
Certificates collected at receiving for structural steel, rebar and anchor bolts, checked that the grade and properties match the approved submittal, filed against the lot they cover, and carried into the closeout package as material traceability.
Checklists that put mill certificate to work
Free, field-ready checklists, each with the photo every item needs before it can be submitted.
Related terms
- SubmittalThe product data, shop drawings or samples a contractor sends for review to confirm what will be installed matches the spec before it's ordered.
- Receiving inspectionThe check of materials and equipment when they arrive on site, confirming what showed up matches what was approved before it gets installed.
- Test reportThe documented result of a test run on installed work or material, recording what was tested, how, and whether it met the criteria.
- Record drawingsThe final drawing set updated to show what was actually built, including field changes, prepared for the owner at closeout.
- Batch ticket (delivery ticket)The ticket that comes with each concrete truck, recording the mix, quantity, water and time so the delivered load can be verified and traced.
- Field reportA dated record of what was observed on site on a given visit: the work seen, conditions found, and any items that need action.
Knowing the term is step one. Proving it is the job.
RTI holds the submit button until every mandatory item is answered and the photos are attached, then chains the record so it can be proven untouched later.
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