The Difference Between EN 10204 Clauses 3.1 and 3.2

The EN 10204 standard 3.1 certificate is a material test document prepared under the manufacturer’s internal quality control system and approved by an authorized representative. The 3.2 certificate, on the other hand, is a more binding document that is jointly approved by both the manufacturer and the buyer or an independent third-party inspection body.

What is the EN 10204 Standard?

In the supply of steel and metal materials, documents containing chemical composition, mechanical properties, and other quality criteria of each production batch are called Material Test Reports (MTR) or certificates of conformity. EN 10204 is the European standard that defines how these documents are issued, approved, and structured.

The standard defines four main document types:

• 2.1 Declaration of Compliance: Manufacturer declares conformity without test evidence.
• 2.2 Test Report: Based on internal production tests, no independent verification.
• 3.1 Inspection Certificate: Issued and approved by the manufacturer’s independent quality unit with test results.
• 3.2 Inspection Certificate: Approved by both manufacturer and an independent inspection authority or buyer representative.

What is a 3.1 Certificate?

A 3.1 certificate is issued and signed by the manufacturer’s independent quality control department. It includes:

• Chemical analysis results (heat and product analysis)
• Mechanical test results (tensile, yield, impact tests)
• Surface inspection results (if applicable)
• Dimensional and tolerance verification
• Heat number and batch identification

What is a 3.2 Certificate?

A 3.2 certificate includes an additional independent verification layer besides the manufacturer’s approval. This second approval may come from:

• The buyer’s authorized inspection representative
• An independent inspection body (e.g., TÜV, DNV, Bureau Veritas, Lloyd’s Register)
• An officially authorized regulatory authority

Main Differences Between 3.1 and 3.2 Certificates

How to Read a Material Test Report (MTR)?

• Heat Number: Must match the physical product marking.
• Chemical Composition: Must comply with standard limits (C, Mn, Si, S, P, etc.).
• Mechanical Properties: Tensile strength, yield strength, and impact values must meet requirements.
• Signatures: 3.1 has one approval; 3.2 has dual approval.
• Standard Reference: Must clearly indicate applicable standard (e.g., EN 10025).

How to Detect Fake or Incorrect Certificates?

• Heat number mismatch
• Generic template documents
• Invalid inspection bodies
• Date inconsistencies
• Unusually low-priced offers

Frequently Asked Questions