EN 10204 Mill Test Certificates (MTC): Types 2.1, 2.2, 3.1 & 3.2 Explained
Crestflo issues a Type 3.1 certificate as standard on every order and Type 3.2 on request, with a heat number marked on every part for full traceability. Delivery runs 6–8 weeks.
In short: EN 10204 is the European standard spelling out which types of inspection documents a metallic-product supplier has to issue with an order. What most customers actually get is a Mill / Material Test Certificate (MTC). There are four types, 2.1, 2.2, 3.1 and 3.2, and they differ based on who inspects the product and who signs off on the results.
Under EN 10204, an MTC, mill test certificate, or material test certificate; the two terms mean the same thing, is an inspection document for metallic products. On this page that's what MTC stands for. It isn't a Medical Training Center, and it isn't any other MTC you might have encountered elsewhere. A Type 3.1 reference describes something else entirely: the validation level of that document. It has nothing to do with material grade, and nothing to do with pressure class.
Request a quote, EN 10204 3.1 MTC included → · sales@crestflousa.com · +1 346 594 9005
What is EN 10204 / a mill test certificate (MTC)?
EN 10204 is the European standard covering the types of inspection documents a supplier of metallic products issues to the purchaser, based on what the order specifies. CEN, the European Committee for Standardization, publishes it, and it also appears nationally as BS EN 10204 and DIN EN 10204. The current edition, EN 10204:2004, replaced the 1991 version.
EN 10204 is the standard behind what most people in the industry call a mill test certificate, or material test certificate, the MTC. In North America you'll often hear it called a mill test report (MTR) or a certified material test report (CMTR); EN 10204 itself just calls it an "inspection document." The name on the purchase order doesn't matter much. Underneath, it's the same thing: a record linking a delivered metal product to its grade and heat, backed by test results, that certifies the material meets the specified standard.
Crestflo instrumentation ships with a specific certificate type, and this page explains why in plain English. EN 10204 itself is copyrighted, so you won't find a PDF or template here, the official document has to come from CEN or BSI. What follows is a rundown of the four document types, what each one actually proves.
EN 10204 MTC: also known as
An MTC goes by a lot of names in drawings, purchase orders, and quality clauses. All the terms below point to the same document family: the EN 10204 inspection certificate.
| Category | Terms covered |
|---|---|
| Standard designation | EN 10204, BS EN 10204, DIN EN 10204, EN 10204:2004, EN 10204:1991 (superseded), "10204" |
| Common output name | mill test certificate, material test certificate, MTC, MTC certificate |
| US equivalents | mill test report, MTR, certified material test report, CMTR, material test report |
| EN 10204's own term | inspection document, inspection certificate, test report |
| Document types | Type 2.1, Type 2.2, Type 3.1, Type 3.2, inspection certificate 3.1, inspection certificate 3.2, material test certificate 3.1 |
| Related concepts | material certificate, declaration of compliance with the order, certificate of conformity, heat / lot / cast number, traceability |
| Legacy 1991 codes | 2.3, 3.1.A, 3.1.B, 3.1.C (no longer used; mapped below) |
EN 10204 standard at a glance
| Attribute | Value (standard published reference) |
|---|---|
| Designation | EN 10204 (also issued as BS EN 10204, DIN EN 10204) |
| Current edition | EN 10204:2004 |
| Superseded edition | EN 10204:1991 (older 2.3 / 3.1.A / 3.1.B / 3.1.C designations withdrawn) |
| Issuing body | CEN, European Committee for Standardization |
| Scope | Specifies the types of inspection documents supplied to the purchaser for metallic products, per the order |
| Common name of output | Mill / Material Test Certificate (MTC); US equivalents MTR, CMTR |
| Document types | 2.1, 2.2, 3.1, 3.2 |
| Inspection basis | 2.1 & 2.2 = non-specific inspection; 3.1 & 3.2 = specific inspection on the delivered product or its cast |
| Certificate Crestflo issues | EN 10204 3.1 as standard on every order; 3.2 on request |
The four EN 10204 document types: 2.1, 2.2, 3.1 & 3.2
EN 10204 doesn't spell out the tests themselves. What it defines is who inspects the product and who checks the results. That split gives you two families. Non-specific inspection (2.1, 2.2) covers documents tied to general production rather than the actual delivered items. Specific inspection (3.1, 3.2) is different: the certificate reports on tests run on the products actually supplied, or on their cast.
| Type | Name | Inspection basis | Validated / signed by | Contains test results? |
|---|---|---|---|---|
| 2.1 | Declaration of compliance with the order | Non-specific | Manufacturer | No |
| 2.2 | Test report | Non-specific | Manufacturer | Yes (from general / non-specific production testing) |
| 3.1 | Inspection certificate 3.1 | Specific | Manufacturer's authorized inspection representative, independent of the manufacturing department | Yes (on the actual product) |
| 3.2 | Inspection certificate 3.2 | Specific | Manufacturer's authorized representative and the purchaser's authorized representative or a designated third party | Yes (on the actual product) |
A Type 2.1 is nothing more than a bare declaration that the order was met, the closest cousin in EN 10204 to a general "certificate of conformity", and it carries no test data at all. A Type 2.2 test report does add results, but they come from non-specific production testing, not from the actual delivered items. The jump to 3.1 is where things change: the certifying inspector has to be independent of the department that made the parts. That independence is exactly what makes a 3.1 the procurement certificate most buyers accept without question. A 3.2 goes further still, bringing in a second validating authority, whether that's the purchaser's own representative or a designated third party like a classification society.
EN 10204 3.1 vs 3.2: which certificate do you need?
Buyers most often ask about 3.1 versus 3.2. Both are specific inspection certificates on the actual product; the difference comes down to who signs off. If the real choice is between 2.2, 3.1, and 3.2, the four-type table above settles it, since only 3.1 and 3.2 report specific inspection on the delivered items.
| Aspect | Type 3.1 | Type 3.2 |
|---|---|---|
| Inspection basis | Specific, on the delivered product / its cast | Specific, on the delivered product / its cast |
| Validating authority | Manufacturer's inspector, independent of production | Manufacturer's inspector plus purchaser's representative or designated third party |
| Independence | Internal, independent of manufacturing | External / third-party validation added |
| Typical trigger | Standard procurement; most projects | Code, classification-society, or client-spec mandate |
| Crestflo availability | Standard on every order | On request |
Crestflo ships 3.1 as standard and provides 3.2 on request, with independent validation arranged to your quality clause.
For most instrumentation purchases, a 3.1 is exactly what the specification calls for and what buyers accept without question. A 3.2 only comes into play when a code, a classification society, or a client's own quality clause insists on independent third-party or purchaser validation.
What appears on a mill test certificate
An EN 10204 3.1/3.2 MTC pulls together identity, metallurgy, and test data on one certified page. The composition and mechanical values live on each grade page, this section shows what fields the certificate records.
| Field | Example content |
|---|---|
| Product / order identification | Part description, order and item number |
| Standard(s) & grade | ASTM / ASME / EN product specification and material grade |
| Heat / cast / lot number | The melt identifier that ties the part to its certificate |
| Chemical composition | Element percentages for the heat (values reported per material grade) |
| Mechanical properties | Tensile, yield, elongation, hardness |
| Heat-treatment condition | e.g., solution-annealed |
| NDT / visual / dimensional results | Relevant inspection and test outcomes |
| Certifying statement & signature | The validating authority's declaration per the certificate type |
On delivered parts, PMI (positive material identification) confirms the grade matches the certificate. A test certificate for stainless steel such as 316/316L or a duplex grade records the same fields, with the numeric ranges specific to that alloy. For the actual composition and mechanical ranges reported on your MTC, see the material grades index and specific pages such as 316 / 316L, Duplex 2205 and Inconel 625.
Heat numbers & material traceability
Crestflo stamps a heat/lot number on every part, and that number ties each item back to its certificate and, from there, to the original melt. That's the whole purpose of an MTC: traceability. Pull a part off the shelf, read the heat number, and a QA reviewer can match it against the composition and mechanical data listed on the MTC.
A 3.1 or 3.2 certificate can also reference conformance to other standards invoked by the order, say, NACE MR0175 / ISO 15156 sour-service requirements or the ISO 15156 co-designation. That way a single documentation trail covers both material identity and service compliance. Crestflo runs a full material traceability program that documents how part, certificate, and melt tie together across an order.
EN 10204 editions & legacy designations
Buyers working from older drawings sometimes still cite the retired 1991 designations. The 2004 edition folded them together, and the mapping below is here for reference, check any edge case against the standard you actually purchased.
| EN 10204:1991 designation | EN 10204:2004 equivalent |
|---|---|
| 2.1 | 2.1 |
| 2.2 | 2.2 |
| 2.3 | Withdrawn |
| 3.1.A | Consolidated (3.2-type validation) |
| 3.1.B | 3.1 |
| 3.1.C | Consolidated (3.2-type validation) |
| 3.2 | 3.2 |
A legacy 3.1.B lines up closest with today's 3.1. If an old spec still references 3.1.A or 3.1.C, read that as a call for independent or third-party validation, and confirm the intended type on the order.
Related standards documented on an MTC
MTC sits above the product-form and service standards a component is built to; it's the proof layer for them. What populates the certificate are the results those standards demand.
| Standard | Role relative to the MTC | Reference page |
|---|---|---|
| ASTM A479 / A269 | Product-form specs whose composition and mechanical results populate the certificate | ASTM A479 · ASTM A269 |
| NACE MR0175 / ISO 15156 | Sour-service material requirements an MTC may reference for conformance | NACE MR0175 · ISO 15156 |
| ASTM F1387 | Compression-tube-fitting performance qualification behind Crestflo fittings | ASTM F1387 |
| Country of origin / TAA | Distinct documentation from the MTC; handled separately | US-origin compliance |
The MTC certifies material and testing, it's separate from country-of-origin and TAA documentation, which gets covered on its own US-origin compliance page.
How Crestflo proves EN 10204 conformance
Crestflo stands behind every certificate it issues with an in-house and accredited testing regime. An MTC is only as good as the testing behind it, and that data on a 3.1 or 3.2 has to hold up under audit.
| Requirement | How Crestflo satisfies it |
|---|---|
| Specific inspection on the product | PMI on delivered parts; hydraulic proof, burst and impulse; pneumatic; flexure and rotary-flex fatigue; vibration; thermal cycling; pull-out; vacuum testing |
| Leak integrity (manifolds) | 100% seat and shell leak test |
| Non-destructive examination | In-house NDT |
| Destructive testing | Carried out at ISO/IEC 17025-accredited laboratories |
| Independent validation (3.2) | Third-party inspection on request; 3.2 certification with independent validation on request |
| Traceability | EN 10204 3.1 certificate as standard (3.2 on request) with a heat / lot number on every part |
Datasheets and CAD models are available to customers on request. Crestflo's quality system is ISO 9001 / 14001 / 45001 & PED certified.
EN 10204 MTC on every Crestflo order
Crestflo ships every in-scope instrumentation with an EN 10204 3.1 mill test certificate as standard, no upcharge, no exceptions. 3.2 is available on request, and every part carries a heat number. That covers:
- Compression tube fittings, single and double-ferrule, tested per ASTM F1387
- Instrumentation valves, needle, ball, check / NRV and double-block-and-bleed
- Valve manifolds, 2-, 3- and 5-valve, with 100% seat and shell leak testing
- Instrumentation pressure regulators and accessories
- Stainless steel & alloy instrumentation tubing
Request a quote, EN 10204 3.1 MTC included →
Talk to us about Type 3.2 or third-party inspection, or request a sample or line card. Other options: become a distributor · master distributor program · contact Crestflo.
US contact: sales@crestflousa.com · +1 346 594 9005 · Houston, TX.
Why Crestflo for certified instrumentation
- A 3.1 certificate on every order. EN 10204 3.1 MTC as standard, 3.2 on request, no upcharge, no exceptions.
Traceable to the melt. Every part carries a heat/lot number tying it back to its certificate, the paper trail an audit demands.
Real testing backs up the paper. PMI, hydraulic proof/burst/impulse, pneumatic, fatigue, vibration, thermal cycling, pull-out and vacuum testing. In-house NDT. Destructive testing at ISO/IEC 17025-accredited labs. Third-party inspection on request.
A drop-in replacement, and proven as one. Fittings are tested per ASTM F1387, so a certified instrumentation line can be swapped out without a redesign.
- Lead time that moves projects. Ready stock for standard items, made-to-order for specials, 6–8 week delivery.
- Honest origin. Indian origin; US / European melt available on request, with full material traceability.
- Small MOQ and private label, both imperial and metric, customizable to requirement.
- Certified quality system: ISO 9001 / 14001 / 45001 & PED certified.
Crestflo is the instrumentation division of a four-decade-old, Government-of-India-recognized export house with a long Middle-East delivery record. Behind the focused, US-serving instrumentation brand sits a genuine manufacturing pedigree. We Engineer Confidence.
Frequently asked questions
What is an MTC for material?
A Mill or Material Test Certificate is an EN 10204 inspection document. It records a metal product's grade, its heat or lot number, chemical composition, and mechanical properties, and it certifies that the material meets the specified standard.
What is MTC certification?
MTC certification means issuing an EN 10204 inspection document, typically a Type 3.1 or 3.2, that confirms a product's test results match its material specification and the order.
What does the EN 10204 standard define?
EN 10204 sets out the types of inspection documents (2.1, 2.2, 3.1, 3.2) that a supplier issues to the purchaser for metallic products. It covers who inspects the product and who validates the results, not the tests themselves.
What is an MTC certificate for steel?
The MTC for steel records the heat number, chemical composition, and mechanical properties, including tensile strength, yield, elongation, and hardness, along with the heat-treatment condition. Together these confirm the steel meets its ASTM, ASME, or EN grade.
What is the difference between EN 10204 3.1 and 3.2?
Both are inspection certificates on the actual product, but they're not the same in weight. A 3.1 gets validated by the manufacturer's inspector, someone independent of production. A 3.2 goes a step further, adding validation from the purchaser's representative or a designated third party.
What is the difference between Type 2.1, 2.2 and 3.1?
A 2.1 is a compliance statement with no test results attached. A 2.2 gives a test report drawn from general, non-specific production inspection. A 3.1, by contrast, covers specific inspection of the actual product delivered, checked independently within the manufacturer's own organization.
Which EN 10204 certificate does Crestflo supply?
Crestflo puts a Type 3.1 certificate on every order as standard, and issues Type 3.2 on request. Every part carries a heat and lot number.
Is an MTC the same as a certificate of conformity?
No. A certificate or declaration of conformity confirms that the product meets the order, closest to EN 10204 Type 2.1, but it doesn't need to carry specific test results. An EN 10204 3.1 / 3.2 MTC, on the other hand, reports actual, product-specific test data.
Does the MTC include heat-number traceability?
Crestflo marks a heat and lot number on every part. That number ties each item back to its MTC and melt, so full traceability is there when it's needed.
Can I get third-party or PMI verification with my certificate?
Crestflo performs PMI and offers third-party inspection on request. Destructive testing runs at ISO/IEC 17025-accredited labs, and 3.2 certification with independent validation is available on request.
Do fittings, valves and tubing all come with an MTC?
All in-scope instrumentation fittings, valves, manifolds, regulators, accessories and tubing ship with an EN 10204 3.1 MTC; 3.2 is available on request.
Which EN 10204 edition is current?
EN 10204:2004 is the current edition, also published as BS EN 10204 and DIN EN 10204. It replaced the 1991 edition, along with the older 3.1.A / 3.1.B / 3.1.C sub-designations that came with it.
Explore related standards & products
Standards: Standards hub · ASTM A479 · ASTM A269 · NACE MR0175 · ISO 15156 · ASTM F1387
Quality: Material traceability · US-origin compliance · Quality overview
Materials: 316 / 316L · Duplex 2205 · Inconel 625 · All materials
Products: Tube fittings · Instrumentation valves · 3-valve manifold · Instrumentation tubing