Mill Test Certificates: EN 10204 2.1, 3.1, 3.2

Quick Reference

A Mill Test Certificate (MTC) certifies the chemical and mechanical properties of steel products. EN 10204 defines four types: 2.1 (declaration only), 2.2 (declaration + non-specific tests), 3.1 (specific test results, manufacturer-validated), and 3.2 (specific test results + third-party validation). MTCs are shipped with other export documents.

Mill Test Certificate

An MTC (also called Mill Test Report or MTR) is a certified document from a manufacturer attesting to a product’s chemical composition and physical properties. For processed products like pipe fittings (elbows, tees, reducers), the manufacturer must provide MTCs for both the finished product and the “mother” material (the pipe used to fabricate it).

Why MTCs Are Critical

Reason	Explanation
Quality assurance	Traceable record that materials meet required standards and specifications
Compliance	Essential for projects adhering to engineering codes (ASME, API, EN)
Safety	Verifies material strength and composition for critical applications
Risk management	Reduces risk of substandard materials causing failures, repairs, or accidents

Field Note

When materials arrive on site, always match the heat numbers on the physical product against the MTC. It takes five minutes and prevents major headaches - I’ve seen entire shipments rejected during client audits because one elbow had a mismatched heat number.

Information Shown on an MTC

Section	Contents
Header	Manufacturer name/address, document title, date, MTC type (e.g., “EN 10204 3.1”), page numbering
Order details	Customer name, PO reference, product definition
Product description	Type (e.g., “Seamless Pipes”), manufacturing process, surface finish, dimensions (NPS × WT × length)
Quantities	Units, nominal weight, net/gross weight
Test results by heat	Chemical composition, tensile strength, hardness, impact values, SSC/HIC results (if applicable)
Additional tests	Hydrostatic, UT, MPI, metallographic examination
Marking	Product marking details for traceability
Validation	Manufacturer QA signatures; third-party inspector signatures (for 3.2)

MTC Types (EN 10204)

EN 10204 defines four certification levels, from basic (2.1) to most stringent (3.2):

Type 2.1 – Declaration of Compliance

Manufacturer declares products comply with order requirements. No test results included. No third-party verification. Suitable for non-critical applications where material properties aren’t safety-critical.

Type 2.2 – Test Report

Manufacturer declares compliance and confirms products were tested per applicable standards. Non-specific test results (summary statements, not actual values). No third-party verification. Used when buyers need more assurance than 2.1 but don’t require detailed test data.

Type 3.1 – Inspection Certificate

Manufacturer provides specific test results (chemical composition, mechanical properties) for the actual batch supplied. Certificate must be validated by the manufacturer’s authorized inspection representative, independent of the manufacturing department. Includes full traceability via heat/batch numbers. This is the standard certificate type for oil & gas, chemical processing, and power generation.

Historical Type	Current Equivalent	Notes
3.1A	3.2	Was issued by independent inspector; replaced 2004
3.1B	3.1	Was manufacturer-issued; replaced 2004
3.1C	3.2	Was customer-appointed inspector; replaced 2004

Pro Tip

Always request MTCs before the shipment leaves the factory, not after arrival. Chasing missing paperwork while materials sit at the port costs storage fees and delays commissioning. Build this into your PO terms.

Type 3.2 – Inspection Certificate with Third-Party Validation

Same as 3.1, plus independent third-party inspector witnesses tests and co-signs the certificate. The third party can be the purchaser’s representative or an accredited inspection agency (SGS, Lloyd’s, DNV, etc.). Required for critical applications where material failure could have catastrophic consequences-aerospace, subsea, nuclear, high-pressure/high-temperature service.

Example of mill test certificate 3.1 (for a pipe)Sample mill test certificate (Tenaris steel pipes).

Summary: MTC Comparison

Type	English Name	German	French	Test Results	Validated By
2.1	Declaration of compliance	Werk-Bescheinigung	Attestation de conformité	None	Manufacturer
2.2	Test report	Werkzeugnisse	Relevé de contrôle	Non-specific	Manufacturer
3.1	Inspection certificate	Abnahmeprüf-Zeugnisse 3.1	Certificat de réception 3.1	Specific	Manufacturer QA (independent of production)
3.2	Inspection certificate	Abnahmeprüf-Zeugnisse 3.2	Certificat de réception 3.2	Specific	Manufacturer QA + third-party inspector

Key Differences

Aspect	2.1 / 2.2	3.1	3.2
Test results	None / Summary	Actual values	Actual values
Third-party	No	No	Yes
Traceability	Limited	Full (heat/batch)	Full (heat/batch)
Typical use	General engineering	Oil & gas, power gen	Critical/safety applications

Fake MTCs: Risks and Prevention

Counterfeit Certificates

Fake MTCs are a serious problem in the steel industry. Substandard materials with forged certificates have caused equipment failures, project delays, and safety incidents. Always verify MTC authenticity.

Consequences of Fake MTCs

Risk	Impact
Safety	Materials that don’t meet specs can fail in service
Legal liability	Penalties, recalls, project shutdowns
Financial loss	Replacement costs, delays, litigation
Reputation damage	Loss of customer trust and future business

How to Detect and Prevent Fake MTCs

Method	Action
Manufacturer verification	Contact the manufacturer directly to confirm MTC authenticity
Third-party inspection	Use independent agencies (SGS, Lloyd’s, DNV) to validate material properties
Check inconsistencies	Review formatting, spelling, data-compare against known genuine certificates
Verify traceability	Cross-reference heat/batch numbers on MTC against physical product markings
Supplier audits	Audit suppliers’ quality systems and documentation practices
Sample testing	Independently test material samples to verify MTC claims

Common Mistake

Accepting photocopies of MTCs without the original stamp. Original MTCs should have a wet signature or an embossed stamp. If you’re getting scanned PDFs from unknown suppliers, verify with the mill directly before accepting the material.

Blockchain and Digital Authentication

Blockchain technology and NFTs (Non-Fungible Tokens) offer promising solutions for MTC authentication:

Capability	Benefit
Digital twin	Each physical product linked to unique blockchain record containing MTC data
Immutable records	Blockchain entries cannot be altered after creation
Provenance tracking	Complete product history from manufacture through ownership changes
Smart contracts	Automated verification before transactions complete

Challenges: Requires secure physical-digital linking (RFID, QR codes), industry-wide standardization, and regulatory compliance. Adoption is still in early stages but growing in critical supply chains.

Related Articles

Testing and Inspection

• Hydrostatic Test - Pressure testing procedures for vessels and piping
• Non-Destructive Testing Types - VI, LP, MP, UT, RT, and EC methods
• Pipe Inspections - Comprehensive guide to pipe inspection types

Procurement and Logistics

• Common Shipping Documents - Documents shipped alongside MTCs
• Third-Party Inspection Certificates - Independent quality verification

Materials

• ASTM, EN, BS Pipe Specifications - Material standards referenced in MTCs
• API 5L Line Pipe Specification - Line pipe grades and testing requirements