Every bar and plate that enters the hall comes with an EN 10204 3.1 inspection certificate, and every batch we ship carries a copy of it. Most people file it. Here is how we read it.
The lines that matter
Heat number. The single most important field. It ties the bar in our rack to the ladle it came from, and it must match the stamp on the material. No match, no cut.
Chemical analysis. Compare it against the grade, not just the grade name. We have received bar stamped 42CrMo4 with a chromium figure at the bottom of the range and a molybdenum figure below it. The certificate was honest; the grade name was optimistic.
Mechanical properties. Yield, tensile and elongation, tested on a sample from the same heat. For anything that will be hardened, we also want the hardenability band.
The lines that do not
The mill’s own order number, the customer’s order number and the signature block. Useful for paperwork, useless for the part.
The field that is most often wrong is the dimension. A certificate for 80 mm bar arriving with 85 mm bar is not a forgery; it is a mill that certified the heat and then cut what it had.
What we do with it
The heat number is written on the traveller and on every offcut. When a part ships, the certificate for its heat goes in the box with the dimensional report. If a customer calls in ten years about a housing, we can tell them which ladle it was poured from.
