A mill test certificate is issued by the producer, such as a smelter, rolling mill, extruder or ingot maker, for a specific heat, cast or lot. It typically shows the grade and standard, heat or batch number, chemical composition, and for semis the temper, dimensions and mechanical test results such as tensile strength, yield and elongation. Some buyers ask for certificates to EN 10204 type 3.1, which are validated by the producer quality department independent of production.
Why it matters when buying
- The MTC links paperwork to metal: check that heat numbers on the certificate match the markings on ingots, bundles or coils.
- Compare every value with the standard and your purchase order, not just the summary line.
- For critical uses, verify independently with a spectro check or third-party test on receipt.
- For EC grade, ask for conductivity results; for foil, pinhole and gauge data.
Notes
Scrap and dross are normally sold without an MTC, so buyers rely on inspection, spectro and trial melts. Listing the documents you need in the RFQ avoids delays at dispatch; see how to write an aluminium RFQ.