EN 10204 3.1 vs 3.2 Mill Test Certificate: Buyer’s Guide

Every serious steel purchase ends with the same question: what paperwork proves the material is what you paid for? For exports from Europe, China, India, Turkey and Korea, the answer is almost always an EN 10204 inspection document — and the fight, when it happens, is nearly always about the difference between type 3.1 and type 3.2. Buyers routinely discover the gap after delivery: a project specification demanded a third-party certificate, the shipment arrived with a mill-issued 3.1, and now the inspector will not release the material. Others pay 3.2 premiums on stock items where it adds nothing. Understanding EN 10204 3.1 vs 3.2 — who issues each, what each legally validates, what must appear on the document, and what each one costs — is the cheapest quality insurance in steel procurement, and it takes about ten minutes to learn. This guide explains the full EN 10204 family (2.1, 2.2, 3.1, 3.2), the rules for who may sign, the certificate contents that auditors check, the classic frauds and shortcuts, and the order language that gets you the right document the first time.

What EN 10204 Actually Is

EN 10204 is the European standard defining “metal products — types of inspection documents.” It does not test the material; it defines who performed the inspection, against what, and who takes responsibility for the statement. The standard recognizes four document types of increasing rigor, plus a delivery note that is not an inspection document at all. The critical design principle is independence: the higher document types demand that the inspection be carried out by someone not involved in manufacturing, on the theory that independence is what makes the statement trustworthy. That principle is exactly what separates a 3.1 from a 3.2, and it is why the two documents cost different money and carry different weight with authorities.

Type	Name	Who inspects and certifies	What it states
2.1	Declaration of compliance	Manufacturer, no test results	Products delivered comply with the order — statement only
2.2	Test report	Manufacturer, non-specific test results	Test results from the production lot or similar material, not necessarily the delivered pieces
3.1	Inspection certificate 3.1	Manufacturer’s authorized inspection representative independent of the manufacturing department	Test results on the actual delivered lot, validated by the manufacturer
3.2	Inspection certificate 3.2	Manufacturer’s representative together with either the purchaser’s representative, or an independent inspection body (SGS, BV, TUV, LR, etc.)	Same as 3.1 plus countersignature of the independent party who witnessed or verified the tests

Read the 2.2 row twice, because it is the trap inside so many cheap offers: a 2.2’s results may come from “similar” material, not the heat in your container. A 2.2 is a legitimate document for low-criticality orders, but it is not traceable evidence about your pieces. If a supplier offers a “mill certificate” without stating the type, ask which one — the silence is rarely accidental.

Type 3.1: The Workhorse Certificate

Type 3.1 is what the overwhelming majority of B2B steel orders should and do carry. The standard’s wording is precise: the tests are carried out by the manufacturer’s inspection organization that is independent of the manufacturing department, and the document is validated by an authorized inspection representative. In plain language, the mill’s own quality department — not the production foreman — tests the material from the actual heat you receive, and a named authorized person signs. This is genuine traceability: heat number, chemistry, mechanical tests, heat treatment, all tied to your delivered lot.

What 3.1 does not include is anyone from outside the manufacturer. The certificate’s honesty rests entirely on the mill’s internal independence and its accreditation. For most commercial applications — general fabrication, machine building, standard piping, structural work not governed by a third-party-inspected regime — 3.1 is fully sufficient and is the default assumption behind EN material standards (most EN product standards specify 3.1 unless the order states otherwise). Costs: nothing beyond the material price in most cases; mills issue 3.1 as standard practice. Verification is cheap and effective — check the mill’s letterhead, the authorized signature name consistency across orders, heat number match against pipe/plate marking, and test values against the standard’s tables.

Type 3.2: When a Third Party Must Be Involved

Type 3.2 exists for situations where the purchaser (or the regulation behind the project) does not want to trust the mill’s own organization alone. The standard offers two routes: the document is validated by the manufacturer’s authorized representative and the purchaser’s own representative who was present at the works, or by an independent inspection organization (classification society or third-party inspection company) acting for the purchaser. In export practice, the second route is universal — the buyer names an inspection agency on the order, the agency witnesses or verifies testing at the mill, countersigns the certificate, and takes contractual responsibility for what it signed.

When is 3.2 genuinely required? The recurring cases: pressure equipment under EU PED categories where the material certificate route chosen demands it; offshore and subsea projects; oil and gas major projects whose specifications list “3.2” explicitly; power plant piping; naval and classification society work; and any purchase specification where the word “witnessed” appears. Beyond those cases, 3.2 on ordinary commercial material buys ceremony, not certainty — the same heat, the same tests, and a fee typically USD 150–600 per shipment plus travel/waiting costs that the supplier passes into the price. If your project specification does not name 3.2, a well-verified 3.1 is the rational choice.

Situation	Right document	Why
General fabrication, stock items, machine parts	3.1	Traceable lot testing, no third-party fee
PED pressure equipment (relevant categories)	3.1 or 3.2 per the material route in the project spec	PED Annex I and harmonized practice dictate the route
Offshore, subsea, major oil and gas	3.2	Project specifications demand independent witness
Classification-surveyed ships and structures	3.2 (class surveyor)	Class rules require surveyor validation
Buyer building own audit regime	3.1 + periodic supplier audits	Cheaper than 3.2 on every shipment

What Must Appear on the Certificate — the Audit Checklist

An EN 10204 document is only as good as its contents, and inspectors check the same fields every time. A conforming 3.1/3.2 identifies: the manufacturer and works location; the type of document; the material identification (product form, grade, standard, dimensions, heat/slab numbers) linking document to delivered goods; the chemical analysis of the heat; the mechanical test results (tensile, impact with temperature and values, hardness where relevant) with specimen details; heat treatment condition and, where applicable, the treatment parameters; NDT results where the order requires them; the statement of conformity to the order and standard; date, place of issue, and the signature block — for 3.1, the manufacturer’s authorized inspection representative independent of manufacturing; for 3.2, additionally the third-party or purchaser representative’s signature with the agency’s name. Digital certificates are acceptable if authenticity is ensured, and many mills issue PDFs with verification codes.

The two fields that generate the most disputes are specimen identity and heat number traceability. Specimen identity: the tests must come from your lot (or from test units that include your lot per the product standard’s sampling plan) — a 3.1 quoting a different heat number than the marking on your goods is void, full stop. Traceability: every delivered length should map to a heat number that appears on the certificate; mixed-heat bundles without per-heat documents are a classic shortcut in low-cost markets and fail the first audit they meet.

The Classic Frauds and Shortcuts, and How to Catch Them

Steel procurement in competitive markets carries a small but real population of certificate games. The ones we see, and the counter-checks:

• Photocopied or edited certificates. The same MTC circulated for different shipments with the date or heat number altered. Counter: check metadata, request the certificate in the mill’s own name directly, verify with the mill via the contact details you find independently (never the ones printed on the suspect document).
• “Similar heat” substitutions. A genuine mill certificate for a heat that is not yours. Counter: heat number on goods must match MTC; do the match at receiving, photograph it.
• Trading house dressed as mill. A trading company issues a “mill certificate” on its own letterhead. EN 10204 validation must come from the material manufacturer — a trader cannot issue a 3.1. Counter: the manufacturer’s name and works address must appear; cross-check the mill exists.
• 3.2 theater. A 3.2 bearing the stamp of an inspection agency the agency never issued — or a “3.2” where the third party merely stamped a document it did not witness. Counter: reputable agencies maintain certificate verification portals and respond to email verification requests; verify every 3.2 on large orders, every time.
• Grade shopping. Material sold as grade X with a certificate for weaker grade Y plus an “equivalence statement.” Counter: equivalence statements are worth nothing in an audit; the certificate must name the ordered grade and standard.

The pattern behind all five: the document claims more independence than the process actually delivered. Verification cost is minutes; undetected, the cost is a rejected shipment, a failed audit or — in pressure equipment — a safety incident. For orders above a trivial value, we build verification into the workflow as standard, and we encourage buyers to do the same with every supplier, including us.

EN 10204 in the Wider World: Equivalents and Misreadings

Buyers working across standards ask how EN 10204 maps onto the American and Japanese systems, and the honest answer is “approximately, with one structural difference.” A mill test report under ASTM practice (A6, A20, B26… or the generic “MTR” culture of the US market) is closest to a 3.1: it reports heat chemistry and lot test results and is validated by the producer. There is no exact American 3.2 equivalent; the US market achieves the same confidence through named third-party inspection (AI) on the purchase order, ASME code data reports and National Board registration, or classification survey — the mechanism differs, the independence principle does not. JIS and GB practice likewise issue mill certificates that function as 3.1 equivalents when they quote heat analysis and lot tests. The misreading to avoid is treating “MTC” as a document type: MTC just means mill test certificate, and the operative question is always which EN 10204 type (or which audit regime) sits behind it. On orders where the specification says “MTC 3.1” write the full phrase “EN 10204 type 3.1” — precision in the order text is free, and it is what the supplying mill’s contract department prices against.

A Receiving and Audit Workflow That Holds Up

Certificates only protect you if they are checked against the goods. The workflow that auditors recognize and that takes minutes per shipment: at order, file the certificate type and any agency scope; at shipment, receive the certificate set before the goods arrive where possible; at receiving, match heat numbers on the pieces to the MTC lines and photograph the matched marking; check chemistry and mechanical values against the standard’s tables (not against memory); file the documents with the PO number and batch record so traceability survives staff turnover. For suppliers, run a periodic verification: once or twice a year, contact the issuing mill through independently found contact details and confirm the certificate serials — or run the check through the agency that countersigned any 3.2. Buyers who operate this loop catch problems while they are still cheap: a wrong heat identified at receiving is a claim; a wrong heat discovered after fabrication and installation is an incident. The workflow costs nothing but discipline, and it is the single strongest answer to the question auditors always ask — “how do you know your incoming material is what the certificate says?”

Order Language That Gets the Right Document

Certificate problems start with vague orders. The line that removes ambiguity: “Inspection certificate to EN 10204 type 3.1 [or 3.2 with inspection by (agency)] for each heat of material delivered, English language, quoting heat chemistry, tensile, impact (temperature, values, specimen size/orientation) and heat treatment condition.” Add for critical orders: “Certificates to be issued in the name of the manufacturer; original PDFs with verification reference; marking on each piece to include heat number.” If 3.2 is required, state who books the agency, who pays the fee and whether testing witness on-site is required versus document review — the price difference between those two scopes is real. And when a project spec says “3.2”, check whether it means every heat or specific product classes; blanket 3.2 on commodity items is money burned that the spec writers rarely intended.

FAQ

Is a 3.1 certificate legally binding? Yes — it is the manufacturer’s statement of conformity with test results on the delivered lot, signed by an authorized representative, and it carries contractual and, under EU law, regulatory weight where the PED route accepts it. What it does not carry is third-party validation.

Can a trading company issue EN 10204 3.1? No. The 3.1 must be validated by the material manufacturer’s authorized inspection representative. A trader can pass through the mill’s 3.1 and add its own cover documents, but the certificate itself must originate from the mill that made the steel.

How much does 3.2 cost? The inspection agency fee for a routine shipment typically runs USD 150–600, plus waiting and travel where physical witnessing is required, and mills charge administrative costs. On small shipments the fee can double the value of commodity material — which is why 3.2 belongs where specifications genuinely demand it.

Does 3.2 test more than 3.1? No — the tests are the same. The difference is who performs and validates them. A 3.2 with document-review-only scope involves exactly the same laboratory results as the underlying 3.1; the third party’s signature attests to the process, not to additional testing.

What replaced the old DIN 50049 3.1B? EN 10204. The old German designations (werkszeugzeugnis 2.2, abnahmeprüfzeugnis 3.1B/3.2B) map onto the EN types directly, and old drawings citing DIN 50049 3.1B should be read as EN 10204 3.1.

We received the shipment but the certificate is missing — what now? Hold the material in quarantine, do not cut or process anything, and request the certificate from the supplier in writing with a deadline, quoting the delivery note and heat numbers read off the pieces. Reputable mills regenerate certificates from their quality system within days because the heat data is archived. If the supplier cannot produce a certificate matching the heat numbers on your goods within a reasonable window, treat the material as untraceable: either reject it, or downgrade it to applications where no certificate is needed — never fabricate it into a certified project with a “certificate to follow,” because the document that eventually arrives will not match the pieces by the time you check.

Buy Steel With Certificates That Hold Up in Audit

Huaxia-Steel ships every export order with EN 10204 3.1 inspection certificates from the producing mill as standard — heat chemistry, mechanical results and heat treatment condition quoted in English, with heat numbers matched to piece marking. Where your project demands 3.2, we coordinate third-party inspection with SGS, BV, TUV or your nominated agency, arrange witness testing at the works and deliver the countersigned certificates with the shipment. Send us your material list and the certificate type your specification requires, and our export team will quote with the documentation scope included — within one working day.