EN 10204 3.1 is a “specific inspection document” — validated by our inspection department, independent of the production line — that certifies the material meets ordered specification and gives real test results from the actual heat.
In 2014 it is treated as the baseline by every serious buyer we work with. We default to 3.1 for every export shipment, and for domestic customers who ask.
The alternative — 2.1 or 2.2 — is a self-declaration or non-specific test report. It is fine for uncontrolled applications, but for wire that ends up in a car, an appliance, or a piece of construction hardware, 3.1 is what auditors want to see.
The whole point is traceability: heat number, cast number, chemical composition, tensile data, all tied to the coil you actually received.