# EN 10204 vs ASTM and ASME: How the Standards Fit Together > EN 10204, ASTM, and ASME aren't rival standards. One governs the certificate, one the material, one the equipment. Here's how they fit on a mill cert. > > **URL:** https://www.gosmarter.ai/blog/en-10204-vs-astm-asme/ **Date:** 2026-06-11 **Author:** Steph Locke **Categories:** blog, learning **Tags:** manufacturing, compliance, metals, quality ## Open a [Mill Test Certificate (MTC)](/hubs/metals-manufacturing-glossary/#mill-test-certificate-mtc) and you will often see "EN 10204 3.1" in one corner and "ASTM A516 / ASME SA516" in another. Buyers ask the same question every time: which standard is the material actually certified to? It's a trick question. EN 10204, ASTM, and ASME are not rival standards. They answer three different questions, and a single certificate often satisfies all three at once. Here's how they fit together. ## Three Standards, Three Questions The quickest way to keep them straight: - **EN 10204** — *is an inspection document standard — it answers "what kind of certificate is this and who authorised it?* - **ASTM** — *is a material specification — it answers "what are the chemical composition, tensile strength, and impact requirements this steel must meet?* - **ASME** — * it answers "is this material approved for use in ASME-coded pressure equipment?"How can this material be used safely?* EN 10204 governs the document. ASTM governs the material specification. ASME governs the equipment built from it. They sit on different axes, so they don't compete but they stack. ## EN 10204: The Certificate Type [EN 10204](/hubs/metals-manufacturing-glossary/#en-10204) is the European standard that defines the *type* of inspection document a mill issues. It says nothing about what the steel is. It only says how the test results were produced and who signed them off. There are four types: | Type | What it means | |------|---------------| | 2.1 | Declaration of compliance. No test results. | | 2.2 | Test report from non-specific inspection — tests on similar product, not your batch. | | 3.1 | Inspection certificate signed by the manufacturer's own authorised representative, tied to your specific heat. | | 3.2 | Same as 3.1, but co-signed by an independent third-party inspector. | When a customer asks for "3.1 certs," this is the standard they mean. They are specifying the *level of assurance*, not the material grade. Supplying a 2.2 when the purchase order says 3.1 is a non-conformance, even if the steel itself is perfect. ## ASTM: The Material Specification ASTM (the American Society for Testing and Materials, now ASTM International) develops the specifications that define a material. An ASTM designation tells you the chemical composition, the mechanical properties, and the tests the metal must pass. You will recognise a few: - ASTM A36 — structural steel - ASTM A516 — pressure vessel plate - ASTM A312 — stainless steel pipe So ASTM answers "what is this material?" Europe answers the same question with its own EN material specs: EN 10025 for structural steel, EN 10028 for pressure vessel plate. ASTM and EN 10025 sit on the *same* axis. EN 10204 sits on a different one. ## ASME: The Design Code The American Society of Mechanical Engineers (ASME) develops the codes that govern how equipment is designed, fabricated, inspected, and operated safely. The best known is the ASME Boiler and Pressure Vessel Code (BPVC). ASME doesn't define the steel. It defines the rules for building safe equipment from it. When a material is adopted into the BPVC for code work, it gets an "SA" prefix. ASME SA516 is the code-adopted version of ASTM A516. The chemistry and properties are virtually identical. The SA designation just means it's cleared for use in code-compliant pressure equipment. ## How They Stack on One Certificate Here's the part that confuses people. A single mill certificate can carry all three at once. Picture a plate of pressure vessel steel: - The **material** is certified to **ASTM A516 Grade 70** (or its dual designation, ASME SA516 Grade 70). - The **certificate** is issued as **EN 10204 Type 3.1** — the manufacturer's representative has signed off the test results for that specific [heat number](/hubs/metals-manufacturing-glossary/#heat-code--heat-number--batch-number). - The finished **vessel** is then fabricated to **ASME Section VIII**. Nothing here is in conflict. EN 10204 describes the paperwork. ASTM/ASME describe the material and the equipment. One document, three boxes ticked. ## What to Check on a Purchase Order Because these are separate axes, a purchase order needs to pin down all of them. Vague specs cause rejected material and delayed shipments. Check: - **Certificate type** — is it 3.1, 3.2, or will 2.2 do? - **Material specification** — ASTM A516, EN 10028, or both (dual-certified)? - **Design code, where it applies** — ASME Section VIII, EN 13445, or a client spec? Get one wrong and you have a non-conformance, even when the other two are correct. ## Why UK and EU Manufacturers See American Standards If you fabricate in Britain, why are ASTM and ASME on your desk at all? Global supply chains. Plenty of UK and EU work is built to American codes. Export contracts, oil and gas projects, and multinational clients who standardise on ASME all drive that. Mills routinely dual-certify plate to both ASTM and the equivalent EN spec so it can be sold either way. The upshot: your quality team has to read certificates against more than one framework, often on the same project. ## Why This Matters for Traceability For procurement, quality, and welding inspection, mixing up these standards is expensive. The risks are familiar: - Wrong certificate type accepted against a 3.1 requirement - Material that meets EN but not the specified ASTM grade - Failed audits when the chain of evidence doesn't line up - Rejected material, rework, and slipped deadlines When you review certificates, you need confidence on all three axes: the right document type, the right material spec, and any design-code requirements. That gets hard fast when you're working across hundreds of certificates and dozens of suppliers. ## Less Paper. More Metal. Most teams still check this by hand, it's often done by opening PDFs one by one, hunting for the cert type, the grade, the heat number, and matching each against the order. It's slow and easy to get wrong. [GoSmarter's MillCert Reader](/products/mill-certificate-reader/), built by Nightingale HQ, reads the certificate and pulls out the EN 10204 type, the ASTM or ASME grade, and the heat number. It checks the values and files everything so you can find it in seconds. The result is faster compliance, cleaner traceability, and far less admin. EN 10204, ASTM, and ASME aren't competing. They describe the document, the material, and the equipment. Once you see them as three questions rather than three rivals, the certificate stops being confusing. Because every hour spent decoding a certificate is an hour not spent making metal. ## Frequently Asked Questions {{< faq question="What is the difference between EN 10204 3.1 and 3.2?" >}} Both are inspection certificates tied to your specific heat. A 3.1 certificate is signed by the manufacturer's own authorised inspection representative, independent of the production department. A 3.2 certificate covers the same test results but is co-signed by an independent third party, such as a customer representative or a notified body. Regulated work often specifies 3.2 where extra assurance is required. {{< /faq >}} {{< faq question="Is ASME SA516 the same as ASTM A516?" >}} The chemistry and mechanical properties are virtually identical. ASTM A516 is the base material specification. When that material is adopted into the ASME Boiler and Pressure Vessel Code (BPVC), it gains an "SA" prefix and becomes SA516. The SA designation confirms the material is cleared for use in code-compliant pressure equipment. Many mills dual-certify plate to both. {{< /faq >}} {{< faq question="Why do UK and EU manufacturers work to American standards?" >}} Global supply chains. Export contracts, oil and gas projects, and multinational clients often standardise on ASME and ASTM. Mills routinely dual-certify plate to both an ASTM grade and the equivalent EN specification, so it can be sold into either market. Your quality team then has to read certificates against more than one framework on the same project. {{< /faq >}} {{< faq question="What should a purchase order specify to avoid a non-conformance?" >}} Pin down all three axes. State the certificate type (2.2, 3.1, or 3.2), the material specification (the ASTM grade, the EN spec, or both for dual-certified plate), and the design code where it applies, such as ASME Section VIII or EN 13445. Get any one wrong and you have a non-conformance, even when the other two are correct. {{< /faq >}} ## Go Deeper - [ASTM vs ASME: What's the Difference?](/blog/astm-vs-asme-difference/) - [AI for Mill Test Report Traceability](/blog/ai-mill-test-report-traceability/) - [EN 10204 and the four certificate types](/hubs/metals-manufacturing-glossary/#en-10204)