# Material test reports (MTRs): EN 10204 types and what to check > What a material test report contains, how EN 10204 types 2.1, 2.2, 3.1 and 3.2 differ, what heat numbers mean, and what to check against the purchase order. URL: https://jjprojectsok.com/knowledge/material-test-reports Español: https://jjprojectsok.com/es/knowledge/material-test-reports Updated: 2026-10-15 What a material test report contains, how EN 10204 types 2.1, 2.2, 3.1 and 3.2 differ, what heat numbers mean, and what to check against the purchase order. **In short:** A material test report (MTR) is the manufacturer's certificate that records the chemistry, mechanical properties and heat treatment of a specific heat of metal, linked to the delivered items by a heat number. EN 10204 defines the document types: 2.1 and 2.2 are manufacturer statements, 3.1 is validated by the manufacturer's independent inspection representative, and 3.2 adds validation by the purchaser's representative or an official inspector. For pressure equipment, buyers usually ask for type 3.1 or 3.2. ## What is a material test report? **Material test report (MTR)**: A certificate, also called a mill test report or mill certificate, that states the chemical composition, mechanical test results and heat treatment of a lot of material, and the specification it was made to. The MTR is the written link between a physical item and its specification. A valve body, a flange or a length of pipe is only as traceable as the certificate behind it. **Heat number**: The identifier given to one melt of metal. All items cast or rolled from that melt carry the number, and the MTR reports the analysis of that melt. A **lot** or **batch** groups items of one heat that were heat treated together. A certificate may report mechanical tests per lot. ## What do EN 10204 types 2.1, 2.2, 3.1 and 3.2 mean? EN 10204 sets the types of inspection documents for metallic products. The number identifies who validates the document and whether the results come from the delivered products. **EN 10204:2004 document types** | Type | Name | Validated by | Test results | | --- | --- | --- | --- | | 2.1 | Declaration of compliance with the order | Manufacturer | None; a statement that the products meet the order | | 2.2 | Test report | Manufacturer | Results of non-specific inspection, not necessarily from the delivered products | | 3.1 | Inspection certificate | Manufacturer's authorized inspection representative, independent of the manufacturing department | Results of specific inspection of the delivered products or their lot | | 3.2 | Inspection certificate | Manufacturer's authorized representative plus the purchaser's authorized representative or an inspector designated by official regulations | Results of specific inspection, with independent validation | The standard's wording governs a contract. Summaries differ on how 3.2 validation is described. **Type 3.1** is the usual requirement for pressure piping, valves and flanges. It ties real test results to the delivered lot. **Type 3.2** adds an independent check. Use it when the purchaser, the code or the regulator requires one, and name the inspection body in the RFQ. EN 10204 is a European standard, but US mills routinely issue certificates to 3.1 on request. Ask for it at quotation, not after shipment. ## What does an MTR contain? - Manufacturer name and certificate number - Customer, order number and item description - Specification, grade and edition (for example ASTM A105) - Heat number and, if used, lot number - Chemical composition: carbon, manganese, phosphorus, sulfur, silicon and alloying elements - Mechanical properties: yield strength, tensile strength, elongation, and hardness where required - Heat treatment: type, temperature and date - Additional tests: impact, NDT, hydrostatic or flattening, when specified - A statement of compliance, signature and stamp of the issuer ## What should you check against the PO? Review every MTR before the material leaves the supplier, and again on receipt. Compare it with the purchase order, not with itself. **MTR checklist** | Check | Against what | Why it matters | | --- | --- | --- | | Specification, grade and edition | PO line item | A different grade or an older edition may carry different limits | | Heat number | Marking on the item | Without a match, the item has no traceability | | Chemistry | Limits in the specification | Confirms the alloy is the one ordered | | Mechanical results | Minimum values in the specification | Confirms strength and ductility | | Heat treatment | Specification and PO | Wrong or missing treatment changes properties | | Supplementary tests | PO: impact, NDT, hardness, sour service limits | Required tests may be absent | | Document type | PO: EN 10204 3.1 or 3.2 | A lower type does not satisfy the order | | Quantity and size | Packing list | The certificate must cover everything shipped | | Signature and stamp | Certificate itself | An unsigned certificate is not a valid 3.1 | For sour service under NACE MR0175 / ISO 15156, check the hardness results against the limits that the specification sets for the grade. ## What are warning signs on a certificate? - No heat number, or a number that does not match the marking - Specification or grade that does not match the PO - A document type lower than the one ordered - Missing manufacturer stamp or signature - Altered text, mixed fonts or evidence of editing - Test results that do not cover the delivered sizes or quantities - Certificate date after the shipping date If any of these appear, hold the material and contact the supplier before use. Never accept a replacement certificate that does not trace to the manufacturer's records. ## How do MTRs relate to PMI and traceability? An MTR documents the heat. **Positive material identification (PMI)** verifies the alloy of the item in front of you, usually with a handheld analyzer. The two complement each other: the MTR gives the record, PMI checks that the item matches it. Keep the MTR with the item through installation. Many projects compile certificates into a final documentation package at handover, so complete records at receipt save time later. ## How can JJ Projects help? JJ Projects reviews certificates against the purchase order as part of procurement and inspection coordination. State the document type you need in your [Request a quote](https://jjprojectsok.com/request-a-quote), or see [procurement services](https://jjprojectsok.com/services/procurement). ## Questions ### What is the difference between EN 10204 3.1 and 3.2? Both report specific test results for the delivered lot. A 3.1 certificate is validated by the manufacturer's inspection representative, who is independent of production. A 3.2 certificate is also validated by the purchaser's representative or an inspector designated by official regulations. ### What is a heat number? A heat number identifies one melt of metal. Every item made from that melt carries the number, and the MTR reports the chemistry of that melt. ### Is a mill test report the same as an MTR? Yes. Mill test report, mill certificate, MTR, MTC and CMTR are names for the same kind of document. Name the EN 10204 type in your order so it is unambiguous. ### Do I need a 3.1 certificate for every item? Only when the order, specification or code requires it. For pressure-containing parts, buyers normally ask for 3.1 and trace it to a heat number. ### Can a supplier issue a 3.1 certificate for material it did not make? A 3.1 certificate must be issued by the manufacturer. A distributor can supply copies traceable to the manufacturer's original, but cannot validate new test results as 3.1. ## Sources - BS EN 10204:2004, Metallic products: types of inspection documents - [Wermac, EN 10204 certificate types](https://wermac.org/din/en10204.html) - [Project Materials, EN 10204 2.1 vs 2.2 vs 3.1 vs 3.2](https://blog.projectmaterials.com/quick-answers/epc/en-10204-certificate-types/) - ASTM A530/A530M, General Requirements for Specialized Carbon and Alloy Steel Pipe - NACE MR0175 / ISO 15156, materials for use in H2S-containing environments in oil and gas production ## Related - [Procurement](https://jjprojectsok.com/services/procurement): Sourcing from manufacturers and authorized distributors, technical and commercial evaluation, purchase-order follow-up, inspection and delivery coordination. - [Steel and structural](https://jjprojectsok.com/products/steel-structural): Carbon, alloy, stainless and copper plate, sheet, line pipe, process tubing, forgings, flanges, fittings, bolting, gaskets and structural steel for industrial projects. - [Request a quote](https://jjprojectsok.com/request-a-quote): Request a quotation for steel, valves, refractory, electrical, safety or IT supply, or for engineering and project management. 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