Material certificates explained: EN 10204 2.1, 2.2, 3.1 and 3.2

Non-specific inspection means the results come from production of the same kind, not necessarily from the delivered batch. Specific inspection means the delivered product, or test units from it, were tested. For machined parts in energy, rail and aerospace applications, 3.1 is the usual requirement because it ties results to the heat of material actually used.

• 3.1 for most structural, pressure-bearing or safety-relevant parts.
• 3.2 when a contract, code or authority requires the inspection to be confirmed not only by the manufacturer's inspection representative but also by the purchaser's authorised representative or by an inspector designated by official regulations — expect longer lead times and extra cost.
• 2.2 may be acceptable for non-critical parts. EN 10204 covers metallic products only, so for engineering plastics a type 2.2 document can only be issued by analogy with the standard.

State the required type on the drawing or purchase order, together with the material standard (for example EN 10088-3 for stainless bars).

A certificate is useful only if the part can be traced back to it. The heat or batch number on the certificate must follow the material through sawing and machining. We record it in our ERP against the production batch and mark parts where the drawing allows; on request, material composition is checked on our own spectrometer. See inspection and documentation.

In the United States and Canada the equivalent document is usually called a mill test report (MTR) or certified mill test report (CMTR). When a US buyer asks for an MTR on a European material, an EN 10204 3.1 certificate normally satisfies the requirement; confirm with the buyer if a specific format is required.