The four EN 10204 certificate types in one table
EN 10204:2004 is the European standard that names the inspection documents a metal producer can issue with a delivery, and the certificate that arrives with a stainless steel order in Saudi Arabia almost always carries one of its four type numbers, wherever the material was rolled. The types split on two questions. Was the inspection specific, carried out on the products actually delivered, or non-specific, a declaration that the producer's general practice meets the order? And who stands behind the statement: the producer, the producer's inspection department, or someone outside the producer?
| Type | Common name | Who issues and signs it | Inspection basis | Who validates the results |
|---|---|---|---|---|
| 2.1 | Declaration of compliance with the order | The producer | Non-specific: no test results are given | Nobody outside the producer; it is a statement of conformity only |
| 2.2 | Test report | The producer | Non-specific: results from tests on the producer's routine production, not necessarily the items delivered | The producer |
| 3.1 | Inspection certificate 3.1 | The producer's authorised inspection representative, independent of the manufacturing department | Specific: tests on the products supplied, or on the heat or lot they came from | The producer's own inspection function |
| 3.2 | Inspection certificate 3.2 | The producer's authorised inspection representative together with a purchaser's representative or an inspector named in official regulations | Specific: the same product-specific tests as 3.1 | An independent party countersigns; the results are validated outside the producer |
The reason 3.1 is the working certificate of the stainless trade is in the last two columns. It is the first type where the numbers on the paper come from tests on the material in front of you, and where the person signing works for the mill's inspection side rather than its production side. A 2.2 test report looks similar at a glance, but its results describe the mill's routine output rather than your heat; a 2.1 declaration has no results at all. A purchase order that says "with mill test certificate" and nothing more will be read as 3.1; write "EN 10204 3.1" so that nobody has to interpret anything.
3.2 is not a better 3.1. The tests are the same tests; what changes is that a second, independent signature says they were witnessed or reviewed. That signature costs money and time, and the fourth section below is about when it is worth both.
Reading the certificate line by line
The heat number, sometimes called the cast number, identifies the batch of liquid steel the product came from. Every chemistry result on the certificate belongs to that heat, so it is the thread that ties the paper to the metal and the first thing to find; a certificate covering several heats carries a chemistry line for each.
The product description states the form, grade, standard, nominal dimensions and quantity: cold-rolled sheet, 304, ASTM A240, 1.5 mm by 1250 mm by 2500 mm, pieces and kilograms. The grade may appear under its EN number (1.4301 for 304, 1.4404 for 316L) or its UNS number (S30400, S31603) rather than the AISI name; the ASTM to EN grade equivalent finder resolves any of those designations to the same grade record, and the 304 and 316L material pages list them side by side. A certificate to EN 10088-2 and a certificate to ASTM A240 are not the same certificate even for the same nominal grade, because the two standards set slightly different limits, and the order decides which applies.
The chemistry line gives the heat analysis in weight percent for each element the standard controls, and every value is read against the standard's range. For 304 plate, sheet and strip to ASTM A240, chromium runs 17.5 to 19.5 percent, nickel 8 to 10.5 percent and carbon 0.07 percent maximum; for 316L, chromium runs 16 to 18 percent, molybdenum 2 to 3 percent and carbon 0.03 percent maximum. A 316L certificate with molybdenum at 1.9 percent, or carbon above 0.03, is not a 316L certificate whatever the header says. The L grades are separated from their parents on the carbon line, 304L to ASTM A240 carrying a maximum of 0.03 percent against 0.07 for 304, and the certificate is the only place that difference is visible. 304 versus 316 stainless steel sets out where the molybdenum earns its cost. A blank element field means the standard does not control that element for the grade, or the mill did not report it, never that its value is zero.
The mechanical line gives the tensile test results on a specimen from the heat or lot: yield strength (as 0.2 percent proof stress, written Rp0.2 on European certificates), tensile strength, elongation and usually hardness. Each has a minimum in the product standard that depends on form and condition, so a result only means something read with both. For 304 plate, sheet and strip to ASTM A240 in the annealed condition the minimums are 205 MPa yield and 515 MPa tensile with 40 percent elongation; for 316L to the same standard and condition they are 170 MPa yield and 485 MPa tensile. A result above the minimum is a pass; the standard does not reward a high number, and a designer who needs more than the minimum has to specify it.
The standard and the condition are the two lines most often skipped. The standard is the rule book the results are judged against; the condition, meaning annealed, solution-annealed, cold-rolled or a stated temper, is the state the mechanical results describe, and a value tested in one condition says nothing about the material after it has been cold-worked or heat-treated again. Last comes the signature block: the signatory's name and function, the certificate type number and a date. On a 3.1 certificate this is the mill's inspection representative; on a 3.2 there is a second signature, and it belongs to the independent party.
Matching the certificate to the material in the yard
A certificate that reads correctly is half the check. The other half is confirming that the paper describes the metal that was unloaded, and that happens at the goods-inward bay, not at a desk.
The heat number on the certificate has to appear on the product. On plate it is normally stencilled or hard-stamped on the surface with the grade, the standard and the mill's mark; on sheet it is on the pack label and often on the top sheet; on coil it is on the coil tag; on bar and pipe it is stencilled along the length or on a bundle tag. Read it against the certificate character for character, because a transposed digit is enough to put the wrong heat on a job. Material with no heat marking cannot be tied to any certificate, and that is a reason to refuse it whatever the paper says.
Count and measure. The certificate states pieces and a weight, and the yard count should agree with it and with the delivery note. Measure the thickness at several points and read the result against the product standard's tolerance rather than the nominal figure, because a 1.5 mm sheet may arrive a little under 1.5 mm and still conform; stainless steel sheet thickness tolerance gives the ranges. If the certificate weight and the scale weight differ, the invoicing basis decides who carries the difference, and theoretical weight versus actual weight explains how plate and sheet are weighed and priced.
Where a delivery has been cut, slit or otherwise processed by a stockholder, the heat number has to travel with each cut piece, as a re-stencil or on a tag; a processor who cannot show which heat a blank came from has broken the traceability chain. Keep the certificate with the job file, not the accounts file: it is the document that answers the first question a failure raises, which is what the material was actually made of, and what is stainless steel covers what those chemistry values mean for how it behaves.
When a specification demands 3.2
A 3.2 certificate is a requirement that comes from the project specification, the pressure code, the classification society or the owner's inspection plan, and it should be treated as one. The independent party is typically a third-party inspection agency, a classification society surveyor or the purchaser's own inspector, who witnesses or reviews the mill's testing and puts a second signature on the results.
Specifications ask for it where a wrong heat has consequences a 3.1 certificate cannot answer for: pressure-retaining parts under a pressure equipment code, structural material in a classed marine or offshore structure, and owner specifications for process plant that call for third-party inspection of pressure-retaining material. There the specification says 3.2 in writing, and the certificate type is a compliance item, not a preference.
The practical consequence is timing. Independent inspection is arranged before or during production at the mill, because the inspector witnesses the tests or reviews them at the time. It cannot be applied after the fact, so an order that needs 3.2 has to say so on the purchase order, and the lead time reflects it. Asking for 3.2 as a precaution on an order that does not require it adds cost and time without adding a single test.
For everything else, which includes most architectural, catering, general fabrication and non-pressure industrial work, a 3.1 certificate to the correct standard, read line by line and matched to the marked material, is the right level of assurance. The failure in practice is rarely the wrong type of certificate; it is the right one that nobody read.
Where Hidayath fits
Hidayath Metal Industries operates from three cities, ten locations and three factories in Saudi Arabia, with branches in Jeddah, Riyadh and Dammam; the group began in 1976. The quality and traceability page sets out how the paper trail runs on an order: grade, standard, form and condition written on the quotation, the mill test report travelling with the delivery where the specification calls for it, and an enquiry reference that traces what was supplied. The material database lists each grade's ASTM, EN and UNS designations and the standards it is supplied against, so a certificate can be read against the same numbers this article quotes. When you request a quotation, state the certificate type and the product standard on the enquiry, so that the offer and the certificate match the specification from the start.