Every despatch in this trade rests on a piece of paper most software has never heard of: the mill test certificate. EN 10204 is the standard that says what that paper is worth. Everyone in a steel office says "3.1" a dozen times a day, but the differences between the four types, and what a stockholder is actually obliged to do with them, catch people out more often than anyone admits.
This is the plain-English version.
What EN 10204 actually is
EN 10204 is a short European standard with one job: it defines the types of inspection document a metal producer can issue with a delivery. It does not tell you what to test or what the limits are. That comes from the product standard and the order. EN 10204 only answers two questions: what is being declared, and who is allowed to sign the declaration.
That second question is the one that matters. The four types are not a ladder of "more testing". They are a ladder of independence: how far the person signing stands from the people who made the material.
The four types, in one paragraph each
Type 2.1, declaration of compliance with the order. The manufacturer states that what they supplied complies with the order. No test results are attached. It is signed by the manufacturer, with no independence requirement. It is a promise, not evidence.
Type 2.2, test report. The manufacturer states compliance and attaches test results, but the results come from routine, non-specific inspection. The numbers on the paper are not necessarily from your batch. Signed by the manufacturer, again with no independence requirement.
Type 3.1, inspection certificate. This is the workhorse of the trade. The results are specific to the material actually supplied, tested against the order and the product standard, and the document is validated by the manufacturer's own authorised inspection representative, someone independent of the manufacturing department. Batch-specific evidence, signed by someone inside the mill but outside production.
Type 3.2, inspection certificate with third-party involvement. Same batch-specific results, but the certificate is countersigned by an independent inspection body or the purchaser's own representative, who witnessed or verified the testing. This is what nuclear, offshore, pressure and defence work tends to demand, and why a 3.2 requirement can add weeks and real money to a mill order.
If you remember one thing: 2.x documents are the maker talking about their process; 3.x documents are evidence about your actual material, with an independent signature on it.
The stockholder's real problem is not the certificate. It is the match.
Mills are generally good at issuing certificates. The failure mode in a stockholding business is downstream: connecting the right certificate to the right material, and keeping that connection alive through everything a stockholder does to steel.
The heat number is the thread. It is the identity of the cast the material came from, and it appears on the certificate and, if the mill has done its job, on the material. The stockholder's obligation is to preserve that thread:
- When a delivery arrives, each batch booked in must be tied to the certificate carrying its heat number, not just "a PDF from that supplier somewhere in the inbox".
- When a bar or plate is cut, every piece that comes off the saw inherits the parent's heat and certificate. A cut does not create new material; it must not create new paperwork ambiguity either.
- When material goes out for processing and comes back, the heat travels with it.
- When a customer or an auditor asks, months later, you need to walk from the despatch note back to the certificate in minutes, not spend a Friday afternoon in the filing cabinet.
Most stockholders can do all of this. The question an audit really asks is whether you can prove it, on demand, for any batch, without heroics.
Where paper-and-spreadsheet systems come apart
Three failure patterns come up again and again.
- The certificate exists but lives as an email attachment, filed by supplier or by month, so finding it means remembering the delivery rather than knowing the heat.
- The heat number was retyped somewhere along the way, and a transposed digit silently broke the chain. Nobody notices until the one day it matters.
- Material was despatched to a customer whose orders require 3.1 minimum, against a batch that only ever had a 2.2. Nobody decided that; the system just had no way to stop it.
None of these are character flaws. They are what happens when certificates are treated as attachments instead of records.
What "certificates as records" looks like
The alternative is to make the certificate a first-class record in the stock system, not a file stapled to one.
In MetlSys, a mill test certificate holds the PDF plus the extracted data: heat, grade, standard, the chemistry and the mechanical values. Certificates auto-match to stock batches by heat number, so the thread is made by the system at goods-in rather than by memory later. Certificate types are ranked 2.1, 2.2, 3.1, 3.2; each customer can carry a minimum acceptable type, and allocation and despatch gate on it. If a batch does not hold a certificate good enough for that customer, the despatch paperwork does not print, and any manager override is logged.
Cutting and processing keep the genealogy: every offcut and every processed piece inherits its parent's heat and certificate automatically, so a remnant on the rack is still certified, sellable material rather than scrap with a chalk mark.
The full traceability workings are described on the features page.
What to do about it
If you hold steel and the words "where's the cert for this?" cost your office more than a minute, the fix is not more discipline. It is filing by heat number, matching at the door, and letting the system enforce what your customers' orders already require.
That is a large part of why MetlSys exists. If you would like to see a certificate matched to a batch in front of you, with your own worst PDF, request a demo.