# EN 10204 3.1 / 3.2 Material Certificates | Buyer Guide

> EN 10204 3.1 vs 3.2 material certificates: which industries require which, what the inspector signs for, the PED link and common rejection causes.

https://www.sinbo-machining.com/wiki/quality/en10204-material-certificate-guide/

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## On This Page

- What EN 10204 Is — and Why the Type Number Matters
- 2.1 vs 2.2 vs 3.1 vs 3.2 — What Each Document Actually Contains
- Which Type Does Your Application Need?
- What the Authorized Inspector Signs For — and What They Don’t
- The PED 2014/68/EU Link — When 3.2 Is Required
- What Most Buyers Get Wrong — The Top 5 Mistakes
- How to Order the Right Cert Type — A Practical Workflow
- Standards & Sources
- Need a 3.1 or 3.2 mill certificate with your order?

# EN 10204 Material Certificate: 2.1, 2.2, 3.1, and 3.2 Explained for Buyers and Suppliers
EN 10204 is the European standard that defines four types of inspection documents (2.1, 2.2, 3.1, 3.2) for metallic products. The type you need depends on what you’re making, who your customer is, and whether the part carries regulatory pressure or safety risk. Most procurement and QA people know they need “a 3.1 cert” but cannot explain the difference between 3.1 and 3.2, or why a 2.1 is not enough for a pressure-bearing part.
## What EN 10204 Is — and Why the Type Number Matters
EN 10204 is the European standard “Metallic products — Types of inspection documents.” The current version is EN 10204:2004 (with a 2017 amendment clarifying the relationship to PED). It replaced the older DIN 50049 in 2004, though the DIN 50049 nomenclature (Werkszeugnis, Abnahmeprüfzeugnis) is still used colloquially in German-speaking markets. The standard defines four types of inspection documents, distinguished by who issues the document and how the test results are validated:
|  Type |  Document name |  Who issues it |  Validation |  Typical use
|  2.1 |  Declaration of compliance |  Manufacturer (mill) |  Self-declaration — the mill states the product meets the order, but no test results are shown |  Non-critical commercial parts; commodity bar stock for non-safety applications
|  2.2 |  Test report |  Manufacturer (mill) |  Non-specific test results from the mill’s standard production testing — not necessarily on the actual delivered batch |  Non-critical parts where the buyer wants some indication of properties, but not specific batch evidence
|  3.1 |  Inspection certificate |  Manufacturer (mill) — signed by the mill’s authorized inspector who is independent of the manufacturing department |  Specific test results on the actual delivered batch (heat number, batch number) |  Most machined parts, structural components, automotive, general mechanical, oil & gas
|  3.2 |  Inspection certificate |  Manufacturer’s authorized inspector and the buyer’s authorized representative (or an independent third party named per EN 10204 3.2) |  Specific test results, validated by both the mill and an independent party |  Pressure equipment (PED), safety-critical parts, nuclear, some aerospace and offshore
The type number is the difference between “trust us” and “prove it.” A 2.1 cert is the mill saying “we made this to your spec.” A 3.1 cert is the mill saying “here are the actual test results on this specific heat of steel you received, signed by a person who is independent of the shop floor that made it.” A 3.2 cert adds an independent second signature — either the buyer’s inspector or a third-party inspection agency.
## 2.1 vs 2.2 vs 3.1 vs 3.2 — What Each Document Actually Contains
Each document type has a defined minimum content. Knowing what the mill is required to put on the document (and what they often leave off) is the difference between accepting a useful certificate and accepting a piece of paper that will get you rejected at your customer’s incoming inspection.
|  Content |  2.1 |  2.2 |  3.1 |  3.2
|  Statement of compliance with the order |  ✓ |  ✓ |  ✓ |  ✓
|  Heat / batch number traceability to the delivered product |  ✗ |  optional |  ✓ required |  ✓ required
|  Actual chemical composition (measured values, not just spec) |  ✗ |  non-specific |  ✓ specific to this heat |  ✓ specific to this heat
|  Actual mechanical test results (yield, UTS, elongation, hardness, impact) |  ✗ |  non-specific |  ✓ specific to this heat/batch |  ✓ specific to this heat/batch
|  Name and signature of the mill’s authorized inspector (independent of production) |  ✗ |  optional |  ✓ required |  ✓ required
|  Independently validated (buyer’s inspector or third party) |  ✗ |  ✗ |  ✗ |  ✓ required
Why “authorized inspector independent of production” matters. A 3.1 cert is not signed by the mill’s sales rep or even the mill’s quality manager in a small mill. EN 10204 specifically requires the signatory to be independent of the manufacturing department — i.e. someone who has no incentive to fudge the test results. In a well-run mill, this is a person in the mill’s central quality function, with written delegation from the mill’s general management. In a poorly-run mill, the same person who runs the heat-treatment furnace also signs the cert — which technically meets the “authorized” requirement but is exactly the kind of arrangement your customer’s auditor will flag.
## Which Type Does Your Application Need?
The application drives the cert type. Below is the typical mapping — confirm with your customer’s purchasing specification, since many OEMs have stricter internal rules than the regulation requires.
|  Application |  Typical minimum |  Why
|  Commercial machined parts, no safety function (e.g. brackets, covers, mounting plates) |  2.1 or 2.2 |  No regulatory pressure; cost is the driver
|  General mechanical parts, OEM-supplied, non-safety |  3.1 |  Standard industrial practice; customer’s QMS expects batch evidence
|  Automotive serial parts (PPAP package) |  3.1 |  AIAG PPAP Element 10; IATF 16949 Clause 8.5.2
|  Pressure equipment under PED 2014/68/EU, Category I–IV |  3.1 (Cat I) to 3.2 (Cat III, IV) |  PED requires specific validation; higher categories require independent third-party validation
|  Oil & gas, sour service (NACE MR0175) |  3.1 minimum; 3.2 common |  End-user specs (Shell, BP, Equinor, Aramco) usually require 3.2
|  Aerospace (AS9100, but typically not EN 10204) |  Heat-traceable MTC per AMS 2774 or equivalent |  Aerospace usually uses AS9100 / AMS standards, not EN 10204
|  Medical implants (ISO 13485, ASTM F136 / F138) |  Mill cert per ASTM A240 + heat traceability |  Medical follows ISO 13485 / ASTM standards, not EN 10204
|  Structural steel for construction (EN 1090) |  3.1 with CE marking per EN 1090-1 |  CE marking under CPR (Construction Products Regulation) requires factory production control + 3.1 cert
|  Power generation (ASME Section I, IV, VIII) |  ASME-style material traceability (not strictly EN 10204 but uses the same concept) |  ASME uses its own data report forms; EN 10204 may be supplementary
PED link. The Pressure Equipment Directive (2014/68/EU, recasting the original 97/23/EC) requires that the material in pressure-bearing parts be traceable and validated. For PED Category I and II, a 3.1 cert is typically sufficient. For Category III and IV, the PED requires either a 3.2 cert or a 3.1 cert with a Notified Body’s third-party validation. Pressure-equipment buyers who accept 2.1 or 2.2 certs for PED Cat III/IV parts are exposing themselves to regulatory and liability risk.
## What the Authorized Inspector Signs For — and What They Don’t
A common misconception is that the authorized inspector (the person who signs the 3.1 cert) takes personal responsibility for the metallurgy. They do not. The 3.1 cert is a controlled document attesting that the mill’s authorized representative has reviewed the test results and they conform to the order. The signatory is attesting to a process, not to a metallurgical opinion.
|  The signatory does attest |  The signatory does NOT attest
|  The product was manufactured by the mill named on the cert |  That the chemistry shown is optimal for the buyer’s end use
|  The heat number shown corresponds to the product shipped |  That the part is suitable for a specific application
|  The test results shown were obtained from testing this heat / batch per the cited test methods |  That the test results will be repeated on the next heat
|  The test results meet the order specification (or any deviation is noted) |  That the part will perform in service
|  The signatory is authorized per the mill’s quality manual and is independent of the manufacturing department |  That the part meets any regulatory requirement beyond the order
Look for the “independent of production” signature. A 3.1 cert signed by the mill’s salesperson, account manager, or production supervisor is technically not a valid 3.1 — the signatory must be in the mill’s quality function, organizationally separate from production. Most large European mills (e.g. Salzgitter, Voestalpine, SSAB) have a dedicated inspection department that signs 3.1 certs; small mills in other regions often do not, which is why customers in regulated industries buy from named mills with a 3.1 cert that they trust.
## The PED 2014/68/EU Link — When 3.2 Is Required
The Pressure Equipment Directive (PED) is EU regulation 2014/68/EU, applicable to any pressure equipment or assembly with a maximum allowable pressure greater than 0.5 bar. It categorizes equipment into Categories I–IV based on the fluid state, fluid group, and pressure / volume combination.
|  PED category |  Material certificate required (per harmonized standard EN 10204) |  Third-party validation
|  Article 4.3 (low risk) |  2.1 or 2.2 acceptable; 3.1 recommended |  No
|  Category I |  3.1 |  No
|  Category II |  3.1 |  No
|  Category III |  3.2 (or 3.1 + Notified Body involvement) |  Yes — either buyer’s inspector or Notified Body
|  Category IV |  3.2 with Notified Body certification of the material |  Yes — Notified Body involvement mandatory
The link between PED and EN 10204 is made through the harmonized standard EN 764-5 (Pressure equipment — Inspection documentation). EN 764-5 explicitly references EN 10204 and adds PED-specific requirements for the inspection certificate (e.g. the CE marking reference, the PED category, the notified body number when applicable). Practical trap: The same stainless-steel fitting may be ordered with a 2.1 cert for a general-industrial application and a 3.2 cert for a PED Cat III pressure vessel. The mill and the heat number are the same. Only the cert type changes — the 3.2 requires a second signatory from the buyer or a third party. If the buyer orders 2.1 by mistake, the only fix is to re-order with the correct cert type, because the original 2.1 cert cannot be upgraded to 3.1 in retrospect (the mill cannot retroactively appoint the buyer as an authorized inspector).
## What Most Buyers Get Wrong — The Top 5 Mistakes
From rejected-cert incidents we have seen on our own incoming inspection and from peers in the procurement community, these are the cert errors that show up most often.
|  # |  Mistake |  Why it happens |  Fix
|  1 |  Buyer orders 2.1 for a PED Cat III part |  Procurement doesn’t know the PED category, or the part isn’t flagged as pressure-bearing in the BOM |  Flag pressure-bearing parts in the BOM; require the cert type on the PO; train procurement on PED
|  2 |  Mill issues a 3.1 but the signatory is the production supervisor, not the quality function |  Small mill, no separate inspection department |  Buy from named mills with an accredited inspection department; audit the mill’s cert process
|  3 |  Cert shows chemistry but no mechanical test results (or vice versa) |  Mill omitted one section by mistake, or it isn’t a “full” 3.1 |  PO must list every test required; incoming inspection checks every section before accepting
|  4 |  Heat number on the cert doesn’t match the bar / billet marking |  Mill shipped from a different heat than the cert was issued for |  Incoming inspection physically checks heat-number marking against the cert
|  5 |  Cert is a generic PDF with no order number, no batch quantity, no delivery date |  Mill re-uses an old template and forgot to fill in the order-specific fields |  PO must list every required field; reject any cert with empty or placeholder fields
The heat-number check is the most underrated step. It takes 30 seconds — compare the heat number stamped on the bar / plate / forging to the heat number on the cert — and it is the single most reliable way to catch a mismatch. A mismatch means the cert does not actually cover the material you received. Do not skip it.
## How to Order the Right Cert Type — A Practical Workflow
For procurement and engineering teams that need a clean repeatable process: 1- Identify the regulatory regime. Is the part pressure-bearing (PED)? Safety-critical (machinery directive, EN ISO 13849)? Structural (EN 1090)? Automotive (IATF 16949)? Medical (ISO 13485)? Each regime has its own cert rule.
1- Map the regime to the EN 10204 type. PED Cat III/IV → 3.2. General industrial → 3.1. Non-critical commercial → 2.2. Commodity → 2.1.
1- List the cert on the PO with full requirements. “EN 10204 3.1 cert required. Must include: heat number, batch quantity, chemistry, yield, UTS, elongation, hardness (or impact where specified), test standards (ISO 6892-1, ISO 6506, etc.), authorized inspector signature. Cert must be in English or bilingual with English.”
1- Train incoming inspection to verify. Heat number matches the material. Cert has all required fields. Test standards cited match the PO. Signatory is in the mill’s quality function, not production. Cert is dated within 12 months of delivery (older certs → ask why).
1- Reject and follow up. If any check fails, reject the lot and ask the mill to re-issue or re-test. Do not “accept with a deviation” — the deviation propagates into your customer’s PPAP and eventually into a field action.
Bilingual certs. If you buy from European mills, the cert will usually be in English or bilingual. If you buy from Chinese, Japanese, or Korean mills, the cert may be in the local language — ask for an English translation or a bilingual cert. Translation must include the signatory’s name and title; a translated cert without a name is a red flag.
## Standards & Sources
Primary standardEN 10204:2004 / EN 10204:2004/AMD1:2017 Metallic products — Types of inspection documents. Defines types 2.1, 2.2, 3.1, 3.2 and the validation requirements for each. Related standardsEN 764-5:2014 Pressure equipment — Inspection documentation. Links EN 10204 to the PED.PED 2014/68/EU EU Pressure Equipment Directive. Defines the categories (I–IV) and the material validation requirements.EN 1090-1:2009+A1:2011 Execution of steel structures and aluminum structures — CE marking, factory production control, FPC cert (refers to EN 10204).DIN 50049 (superseded) Older German standard — the Werkszeugnis / Abnahmeprüfzeugnis nomenclature maps to EN 10204 2.1 / 3.1 / 3.2.ISO 10474:2013 Steel and steel products — Inspection documents. ISO equivalent of EN 10204 (with minor differences).ASTM A480/A480M General requirements for flat-rolled stainless and heat-resisting steel (used for ASTM-side certs, not EN 10204). Test standards commonly cited on a 3.1 certISO 6892-1:2019 Tensile testing at room temperature.ISO 148-1:2016 Charpy impact test.ISO 6506-1:2014 Brinell hardness.ISO 6507-1:2018 Vickers hardness.ISO 6508-1:2015 Rockwell hardness.ASTM E415 / E1086 Optical emission / XRF spectroscopy for chemistry.EN 10002-1 (withdrawn, replaced by ISO 6892-1) Older tensile testing standard. Frequently Asked Questions What is the difference between EN 10204 3.1 and 3.2? A 3.1 cert is issued by the mill and signed by the mill’s authorized inspector who is independent of production. It shows actual test results on the specific heat of material you received. A 3.2 cert has the same content, but is additionally signed by the buyer’s authorized representative or an independent third party named per EN 10204 3.2. The 3.2 is the higher level of validation and is required for high-risk pressure equipment under PED 2014/68/EU Categories III and IV, and for many oil & gas and offshore end-user specifications. Is a 2.1 cert acceptable for an automotive part? No — not for a part going into a PPAP package or any safety-related application. AIAG PPAP Element 10 (Material / Performance Test Results) requires batch-specific test results, which only a 3.1 cert provides. A 2.1 cert is a self-declaration with no test data, which is below the bar for automotive. For PPAP, the part must ship with a 3.1 cert showing chemistry, mechanical properties, and the heat number tied to the delivery. Can a 2.1 cert be upgraded to 3.1 after the fact? No. The 3.1 cert is a document that must be issued at the time of manufacture, signed by the mill’s authorized inspector. The mill cannot retroactively convert a 2.1 to a 3.1 — the test data was either captured at the time (in which case the cert should have been 3.1 from the start) or it wasn’t. The only options are to re-order the material with the correct cert type, or to have the material independently tested and re-certified (rare, expensive, and usually not accepted by the customer). Always order the correct cert type up front. Who is the “authorized inspector” on a 3.1 cert? The authorized inspector is a person in the mill’s quality function who is organizationally independent of production, has been formally delegated in writing by the mill’s general management, and is named in the mill’s quality manual. In a large mill, this is a person in a central Inspection or Quality Assurance department. In a small mill, it may be the same person who also handles other quality functions, but they must still be independent of the manufacturing department that made the product. The signatory’s name, title, and the mill’s stamp or electronic signature must appear on the cert. Does EN 10204 apply to non-metallic materials? No. EN 10204 applies only to metallic products (steel, stainless, aluminum, copper, titanium, nickel alloys). For plastics, elastomers, and composites, different standards apply — e.g. ISO 1043 for plastic marking, EN 10245 for wire coatings, or material-specific ISO/ASTM standards. For polymers used in food contact or medical, the relevant regulations (EU 10/2011, FDA 21 CFR, USP Class VI) are not based on EN 10204 at all. What is the difference between EN 10204 and DIN 50049? DIN 50049 was the German predecessor to EN 10204 and is now superseded. The DIN 50049 nomenclature (Werkszeugnis 2.1, Werkszeugnis 2.2, Abnahmeprüfzeugnis 3.1.A, 3.1.B, 3.1.C, 3.2) is still used colloquially in German-speaking markets but has been replaced by the EN 10204 type numbers. The mapping is: DIN 50049 2.1 = EN 10204 2.1; 2.2 = 2.2; 3.1.A/B/C = 3.1; 3.2 = 3.2. When you see a German mill cert referencing “Abnahmeprüfzeugnis 3.1”, it is a 3.1 cert per EN 10204. Sources & Standards Referenced 1- EN 10204:2004 / EN 10204:2004/AMD1:2017: Metallic products — Types of inspection documents (2.1, 2.2, 3.1, 3.2)
1- EN 764-5:2014: Pressure equipment — Inspection documentation (links EN 10204 to PED)
1- PED 2014/68/EU: EU Pressure Equipment Directive (categories I–IV)
1- EN 1090-1:2009+A1:2011: Execution of steel structures and aluminum structures — CE marking, FPC
1- DIN 50049 (superseded): Older German standard, nomenclature now mapped to EN 10204
1- ISO 10474:2013: Steel and steel products — Inspection documents (ISO equivalent of EN 10204)
1- ISO 6892-1:2019: Tensile testing at room temperature (commonly cited on 3.1 certs)
1- AIAG PPAP 4th edition, Element 10: Material / Performance Test Results (requires 3.1 cert for automotive parts)

## Need a 3.1 or 3.2 mill certificate with your order?
We supply CNC machined parts with full EN 10204 3.1 mill certificates — chemistry, mechanical properties, heat-number traceability, and authorized-inspector sign-off. For PED Cat III / IV parts we can arrange 3.2 through third-party inspection agencies. [Request a Quote ](https://www.sinbo-machining.com/quote/)