EN 10204 3.1 vs 3.2 Certificates: Requirements and Cost

Written by: Emma, Technical Sales Engineer  |  Reviewed by: Ethan, Materials Engineer  |  Updated: August 2026

Introduction

When a purchase order for stainless steel plate, sheet, pipe, or tube says "provide a certificate," the buyer and the supplier may be picturing two different documents. The phrase EN 10204 3.1 vs 3.2 is where that ambiguity usually gets resolved — but only if both sides understand what each type actually represents.

The two certificate types are often treated as a simple "3.1 is normal, 3.2 is premium" choice. That framing misses the point. The real difference is who inspects, who validates, and how much independent verification is attached to the material. A 3.2 certificate does not mean the steel is inherently "better" — it means the test results were validated with a higher level of independent or buyer-side involvement.

This guide explains what EN 10204 3.1 and 3.2 certificates are, who signs them, why 3.2 costs more, and how to specify the right one in a purchase order.

1. What Is EN 10204?

EN 10204 is a European standard that defines the types of inspection documents supplied for metallic products. It does not specify the tests themselves — the applicable product standard (such as an ASTM or EN material specification) defines the required tests. EN 10204 instead defines the level and type of inspection document that accompanies the material, and who is responsible for validating it.

The standard defines a hierarchy of document types. The two most important for buyers are the inspection certificate 3.1 and the inspection certificate 3.2, both of which are based on specific inspection — meaning the testing is performed on the actual product being delivered and is traceable to its heat or batch. This is what distinguishes a 3.1 or 3.2 certificate from a simple manufacturer's declaration or a test report based on general data.

The standard defines a hierarchy of document types, and understanding where 3.1 and 3.2 sit in that hierarchy clarifies why they matter. At the lower end are declarations of compliance and test reports based on non-specific inspection — documents that do not tie test results to the specific delivered product. At the higher end are the inspection certificates 3.1 and 3.2, which are based on specific inspection performed on and traceable to the actual material being supplied. For a buyer who needs real evidence about the delivered steel, this distinction between non-specific and specific inspection is what separates a 3.1/3.2 certificate from a simpler document.

It is worth noting that EN 10204 itself is a European standard. It is related to, but distinct from, other certification concepts — a buyer should not treat "EN 10204 Type 3.1" as interchangeable with an ASTM material test certificate format or an internal supplier certificate.

A final note on terminology: older orders sometimes still reference "3.1B" and "3.1C" from the previous edition of the standard. In the current framework, the concept of a manufacturer-validated certificate corresponds to 3.1, and the concept of an additionally buyer/third-party-validated certificate corresponds to 3.2. If a legacy specification uses the old designations, it should be clarified against the current edition before ordering.

2. What Does 3.1 Mean?

An EN 10204 Type 3.1 inspection certificate is a document in which the manufacturer declares that the supplied products comply with the order requirements and supplies the test results from the specific inspection performed on the delivered material.

The defining feature of 3.1 is who validates it: the document is validated by the manufacturer's own authorized inspection representative, who must be independent of the manufacturing department. In other words, the person signing cannot be the same person who produced the material — the manufacturer's quality function verifies the results, but no external or buyer-side party is involved.

This makes 3.1 the standard, widely used certificate for most commercial stainless steel orders. It provides specific, traceable test results validated within the manufacturer's own quality system.

3. What Does 3.2 Mean?

An EN 10204 Type 3.2 inspection certificate contains the same manufacturer declaration and test results as a 3.1 — but with an additional layer of validation. A 3.2 certificate is validated by both the manufacturer's authorized inspection representative and the purchaser's authorized inspection representative, or an inspector designated by official regulations (such as an independent third-party inspection body).

This is the essential difference: 3.2 adds independent or buyer-side verification to the manufacturer's own declaration. The third party typically witnesses the testing or sampling, reviews the results, and confirms that the material complies with the specified requirements. This is why 3.2 is requested for code-governed, safety-critical, or pressure-equipment applications where an independent check is required.

The practical meaning: a 3.2 certificate carries more assurance about verification — not more assurance that the underlying steel is "better quality." It is about the level of inspection and independent confirmation, not about the material being a higher grade.

4. 3.1 vs 3.2: Key Differences

5. Who Inspects and Who Signs?

Understanding the roles avoids the most common confusion around these certificates:

• Manufacturer's inspection representative — a person within the manufacturer's organization who is independent of the manufacturing department. This person validates the 3.1 certificate.
• Purchaser's authorized inspection representative — a person authorized by the buyer to verify the material and results on the buyer's behalf.
• Independent third-party inspection body — an external organization (such as a notified or recognized inspection body) that witnesses testing, reviews documentation, and validates compliance. This role is distinct from the manufacturer's own quality department.

The key point is that a third-party inspection body is not the same as the manufacturer's quality department. In a 3.1 certificate, the manufacturer's own independent quality function validates the results. In a 3.2 certificate, an additional external or buyer-side party is involved in the validation.

6. What Information Should the Certificate Contain?

The certificate is a traceability and evidence document. While the exact format is not fixed by EN 10204 as a single universal layout, a certificate typically records:

• Product identification — what the material is, including grade and any applicable standard designation.
• Heat or batch number — the traceability link between the certificate and the physical material.
• Chemical composition — the analyzed chemistry for the heat.
• Mechanical properties — the required mechanical test results (e.g., tensile, and other tests as required by the product standard).
• Test results — the results of the specific inspection performed.
• Statement of compliance — confirmation that the products meet the order requirements.

The specific tests and values that must appear are defined by the product standard and the order, not by EN 10204 alone. A buyer should therefore specify both the certificate type and the required tests in the purchase order.

In practice, a buyer reviewing a certificate should be able to answer three questions from the document itself: What material is this? (grade and standard designation), Which physical items does it cover? (heat or batch number traceable to the delivered goods), and Does it meet the order? (test results and a statement of compliance). If any of those three cannot be answered from the certificate, the documentation is not doing its job regardless of whether it is labeled 3.1 or 3.2.

7. Cost and Lead-Time Differences

A 3.2 certificate typically costs more and takes longer than a 3.1, for reasons that are straightforward:

• Third-party inspector involvement — an external inspection body must be engaged, which carries its own fees.
• Witnessed testing or sampling — the inspector may need to be present when tests are performed or samples taken.
• Document review and coordination — additional review and coordination between the manufacturer, the buyer, and the inspection body.
• Scheduling and waiting time — arranging witness testing and document issuance can extend the lead time.

There is no fixed or universal price or percentage difference between 3.1 and 3.2 — the actual cost depends on the product, the tests required, the inspection body involved, and the location and scheduling. Buyers should request a specific quotation rather than assume a standard surcharge.

From a procurement-planning perspective, the cost of a 3.2 certificate is best treated as part of the total cost of compliance, not as an isolated line item. If the application requires 3.2, the additional inspection and lead time should be built into the project schedule from the start, because arranging witnessed testing and document review cannot always be compressed at the last minute. Where 3.2 is not required, requesting it "just in case" adds cost and delay without adding value.

8. When Should Buyers Request 3.1 or 3.2?

The decision between 3.1 and 3.2 is driven by the application, the governing code or regulation, and the contract. As a general guide:

The final authority is the contract, the applicable product standard, and the relevant regulation. A 3.2 certificate is not automatically required for all pressure equipment, and a 3.1 is not automatically sufficient for all regulated applications. The requirement must be determined case by case.

A practical rule of thumb: if the application is a standard commercial order where the manufacturer's own quality system provides sufficient assurance, 3.1 is usually the appropriate and cost-effective choice. If the governing code, regulation, or project specification requires independent or buyer-side verification — or if the buyer's own quality policy demands an independent check — then 3.2 is the correct request. When in doubt, the governing document, not a guess, should decide.

9. How to Specify Certification in a Purchase Order

The following is an example purchase requirement (not standard text):

A complete specification states the certificate type (3.1 or 3.2), the required tests, and — for 3.2 — the inspection body and witnessing requirements, as required by the contract.

10. Common Purchasing Mistakes

• Treating 3.1 as "normal" and 3.2 as "premium quality." They differ in verification level, not material quality.
• Assuming 3.2 is always required for pressure equipment. The requirement depends on the code, regulation, and contract.
• Confusing a third-party inspection body with the manufacturer's quality department. These are different roles.
• Requesting a certificate without specifying the required tests. EN 10204 defines the document type, not the tests.
• Assuming 3.1 can replace 3.2, or vice versa. The verification level differs; substitution must be authorized.
• Not confirming the heat/batch number ties the certificate to the delivered material. Traceability breaks without it.
• Using an outdated or inapplicable certificate concept. Confirm the current EN 10204 edition and the contract-specified requirements.
• Treating EN 10204 3.1 as interchangeable with an ASTM MTC format. They are different certification frameworks.

11. Buyer Acceptance Checklist

• Certificate type is 3.1 or 3.2 as specified
• Heat or batch number matches the delivered material
• Grade and UNS designation match the order
• Chemical composition and mechanical results are recorded
• Required tests are present and pass
• Certificate is validated by the correct party (manufacturer's inspector for 3.1; plus independent inspector for 3.2)
• Statement of compliance with the order requirements is present
• Documentation ties the certificate to the specific delivered items

Frequently Asked Questions

Q1: What is the difference between EN 10204 3.1 and 3.2?
A 3.1 certificate is validated by the manufacturer's own independent inspection representative. A 3.2 certificate adds independent or buyer-side validation by a purchaser's authorized inspector or a third-party inspection body. The difference is the level of independent verification, not material quality.

Q2: Who signs an EN 10204 3.1 certificate?
The manufacturer's authorized inspection representative, who must be independent of the manufacturing department.

Q3: Does EN 10204 3.2 require a third party?
3.2 requires validation by the manufacturer's inspector plus the purchaser's authorized inspection representative or an inspector designated by regulations — typically an independent third-party inspection body.

Q4: Is a 3.2 certificate more expensive than 3.1?
Typically yes, due to third-party inspection, witnessed testing, document review, and scheduling. The exact cost depends on the product, tests, and inspection body, and should be quoted specifically.

Q5: Is 3.2 required for all pressure equipment?
No. The requirement depends on the applicable code, regulation, and contract. Some pressure-equipment applications require 3.2; many do not. It must be determined case by case.

Q6: Can a 3.1 certificate replace a 3.2?
Not automatically. A 3.1 lacks the independent or buyer-side validation of a 3.2. Substitution must be authorized by the contract or specification.

Q7: What is the relationship between MTC and EN 10204?
EN 10204 defines the types of inspection documents; a mill test certificate is one form of such a document. A "MTC" should be specified as an EN 10204 type (3.1 or 3.2) so the verification level is defined.

Q8: How do I specify EN 10204 certification in a purchase order?
State the certificate type (3.1 or 3.2), the required tests, and — for 3.2 — the inspection body and witnessing requirements, as required by the contract.

Q9: Does a 3.2 certificate mean the material is higher quality?
No. A 3.2 certificate means the test results received a higher level of independent verification. The underlying material quality is determined by the grade and the applicable product standard, not by the certificate type.

Q10: Is a 3.1 certificate the same as a 2.2 test report?
No. A 3.1 inspection certificate is based on specific inspection of the delivered product and is traceable to its heat or batch. A 2.2 test report is based on non-specific inspection and does not carry the same traceability to the specific delivered material. For buyers who need evidence tied to the actual goods, 3.1 is the relevant document.