EN 10204 3.1 vs 3.2 Material Certificates

What is EN 10204?

EN 10204 is the European standard that defines the types of inspection documents issued for metallic products — including castings, forgings, plate, bar and tube. It specifies what information a certificate must contain, who must carry out the inspection, and who is authorised to sign the document.

When a buyer specifies "EN 10204 3.1" or "EN 10204 3.2" on a purchase order, they are defining the level of independent verification they require for the material supplied. The two certificate types differ in one critical respect: who witnesses and validates the inspection results.

The four certificate types under EN 10204

EN 10204 defines four document types in total. The two most relevant to industrial castings and pressure equipment are 3.1 and 3.2, but it helps to understand the full hierarchy:

• 2.1 — Declaration of Compliance: the manufacturer declares that the product meets the order requirements. No test data is included. Lowest level of assurance.
• 2.2 — Test Report: the manufacturer provides test results, but these may be based on non-specific testing (e.g. results from a product batch rather than the specific delivery). Not traceable to individual parts.
• 3.1 — Inspection Certificate: specific test results for the actual material supplied, validated and signed by the manufacturer's own authorised inspection representative. The inspector is independent of the production department but employed by the manufacturer.
• 3.2 — Inspection Certificate: specific test results validated and signed by both the manufacturer's authorised inspection representative and an independent third-party inspector — either the purchaser's representative or a notified body (such as Bureau Veritas, Lloyd's Register, TÜV, DNV or SGS).

The key difference: who signs the certificate

Certificate type	Signed by	Third-party witness required
3.1	Manufacturer's authorised inspection representative	No
3.2	Manufacturer's authorised inspection representative and independent inspector	Yes

The "authorised inspection representative" under 3.1 must be independent of the manufacturing department — typically a quality manager or designated inspection engineer employed by the foundry or mill. Under 3.2, a second signature from an external party is required: this is either a representative nominated by the purchaser, or an accredited notified body acting as an independent witness.

What each certificate must contain

Both 3.1 and 3.2 certificates must include the same core information:

• Identification of the product — description, dimensions, quantity and heat/cast number
• Reference to the product standard and order specification
• Results of all required chemical analysis (spectrometer or wet analysis)
• Results of all required mechanical tests — tensile strength, proof stress, elongation, hardness, impact (where specified)
• Results of any non-destructive testing required by the specification or order
• Heat treatment condition (e.g. solution annealed, normalised, T6)
• Declaration of compliance with the order requirements
• Name, position and signature(s) of the authorised signatory or signatories

The difference is not in the content of the certificate — it is in the independence of the person or body confirming that the results are genuine and traceable to the specific material shipped.

Which certificate type do you need?

The right certificate type depends on the application, the applicable standard and what your customer or regulator requires. As a general guide:

• 3.1 is sufficient for most commercial pressure applications, including PED Category I and II equipment, where no independent witness inspection is specified in the design standard or purchase order. It is the default certificate type for investment castings supplied to EN 10283 or ASTM A351.
• 3.2 is required when the applicable standard explicitly calls for it (e.g. certain clauses of NORSOK M-650, API 6A, EN 13480 for pressure piping above certain categories), when your own quality plan or customer purchase order specifies it, or when the equipment classification under PED requires notified-body involvement.
• 3.2 with notified-body witness is typically required for PED Category III and IV pressure equipment, for nuclear-related components, and for offshore equipment subject to NORSOK or DNV standards.

If you are unsure which certificate type your application requires, check the applicable product standard first (EN 10283 for steel castings, EN 1706 for aluminium castings, ASTM A351 for stainless steel castings), then refer to your equipment design standard. If your purchase order does not specify a certificate type, 3.1 will be supplied by default.

Practical implications for buyers

Specifying 3.2 when 3.1 is sufficient adds cost and lead time without adding technical value. Conversely, accepting 3.1 when your standard or customer requires 3.2 creates a compliance gap that may not surface until final inspection or audit — at which point it is expensive to resolve.

• Cost: 3.2 certification typically adds 5–15% to the material cost of a casting batch, depending on the notified body used and the inspection scope. For large batches the increment is proportionally lower.
• Lead time: notified-body witness inspection must be scheduled in advance and requires the inspector to be physically present at the foundry during testing. This typically adds 3–10 working days to the production schedule.
• Traceability: both 3.1 and 3.2 certificates are specific to the material supplied. The heat number on the certificate should match the marking on the casting — verify this on receipt as part of incoming inspection.

How we handle certification at Bruynseels

We supply EN 10204 3.1 certificates as standard with all stainless steel and aluminium alloy castings. EN 10204 3.2 certification with notified-body witness (Bureau Veritas or equivalent) is available on request and should be specified at the time of enquiry so that inspection scheduling can be incorporated into the production plan.

All certificates are specific to the batch shipped — heat numbers on certificates match casting markings — and are included in the shipment documentation. Digital copies are provided on dispatch.