In EN 10204 3.1 vs 3.2, both certificates give you test results for the actual batch of steel supplied. The difference is who signs. A 3.1 is validated by the manufacturer's own authorised inspection representative, independent of production. A 3.2 adds a second validator: the buyer's representative or an inspector designated by official regulations. Same steel, extra independent check.
EN 10204 3.1 vs 3.2 Side by Side
| Type 3.1 | Type 3.2 | |
|---|---|---|
| Test results from your batch | Yes | Yes |
| Who validates | Manufacturer's authorised inspection representative, independent of production | That representative plus the purchaser's representative or an inspector designated by official regulations |
| Changes the steel itself? | No | No |
| Extra cost and time | No outside inspector needed | Inspector time, travel and scheduling |
Who Signs a 3.1 and Who Signs a 3.2
In everyday trade the EN 10204 material certificate is often called an MTC, so "MTC 3.1" and "MTC 3.2" mean EN 10204 type 3.1 and EN 10204 type 3.2.
Type 3.1. The signer works in the maker's quality or inspection function, not on the production line. That separation is what "independent of the manufacturing department" means. It is still the maker vouching for its own steel, so a 3.1 certificate is the right document whenever your order asks only for a 3.1.
Type 3.2. Here the maker's representative is joined by someone from outside the factory: the purchaser's own authorised inspector or an inspector designated by official regulations. In practice that is often an inspection agency such as Bureau Veritas, SGS, TÜV, Lloyd's Register or DNV, named in the purchase order. People sometimes call it a third party inspection certificate 3.2, but strictly the second signer is the purchaser's representative or a designated inspector, not just any third party. A 3.2 is meant to reflect an inspection actually carried out, so an existing 3.1 cannot simply be relabelled.
Is 3.2 Better Steel? No
This is the point most worth getting right. Chemistry and mechanical properties come from the material specification, not from the certificate type. A 3.2 does not mean stronger, purer or more corrosion-resistant steel. It means one more independent person has validated the same results. If a seller charges extra for "3.2 material" as though it were a superior grade, ask what exactly the extra money covers.
The Four EN 10204 Certificate Types
Every EN 10204 inspection certificate or document falls into one of four types:
| Type | Document | Test results | Validated by |
|---|---|---|---|
| 2.1 | Declaration of compliance | None | Manufacturer |
| 2.2 | Test report | Non-specific (not necessarily your batch) | Manufacturer |
| 3.1 | Inspection certificate | Specific to the supplied product | Manufacturer's independent inspection representative |
| 3.2 | Inspection certificate | Specific to the supplied product | Manufacturer's representative plus purchaser's representative or designated inspector |
For what each box on a certificate means, see our separate guide on how to read a mill test certificate.
When Is a 3.2 Actually Required?
EN 10204 describes the documents. It does not decide which one your job needs. That comes from your purchase order, project specification, contract or a governing regulation. In India that works out as follows.
- Government tenders (CPWD, PWD and others): We found no public rule making 3.2 compulsory for all tenders. The tender's own specification decides.
- Boiler (IBR) work: IBR has its own statutory certification process with recognised inspecting authorities. A project may additionally ask for 3.2, but do not assume IBR automatically means 3.2.
- BIS: This is a separate system. It relates to Indian Standards and product certification, and neither replaces the other.
- Export and pressure equipment: Not every export to Europe needs 3.2. For EU pressure equipment it varies with the equipment category and route, so follow your buyer's order.
- Sour (H2S) service: The NACE standard on its own does not appear to mandate 3.2, while operator specifications often do. This is unlikely to concern small buyers.
For everyday purchases such as kitchen fitouts, small fabrication or scrap lots, a 3.2 applies only if your order specifically asks for it. The bigger question is whether the steel in front of you matches what the paper says.
Cost and Lead Time of a 3.2
The extra cost is mostly inspector time, travel and scheduling, and the extra delay is mostly waiting for the inspection to be arranged. Published figures vary widely and we found no reliable India-wide benchmark, so we are not quoting a rupee figure or percentage. Ask for a written quotation stating both cost and dispatch date.
Need 3.2 but Offered 3.1? What to Ask
Raise it before the order is finalised, not after the steel is made. Ask, in writing:
- Can a 3.2 be supplied for this order?
- Which agency or purchaser's representative will do the inspection?
- Who pays, and how does the dispatch date change?
Then put the agency's name in the purchase order. Some inspection bodies offer verification of existing stock "to the intent of 3.2". That is not a true 3.2, and the buyer must agree to it in advance.
How to Verify with MOLY
A certificate, whether 3.1 or 3.2, shows what the maker or inspector states about a batch. It is necessary but not sufficient, because you still need to check that the steel in your hand is what the paper describes, and the heat number on the certificate should match the marking on the steel. A quick spot test on the piece itself is a separate, practical screening step. If you are weighing up local suppliers, our local vendor verification checklist shows what to check before you pay.
To screen stainless steel with MOLY stainless steel testing liquid, the kit includes 15 ml of testing liquid, one 9V battery, a two-pronged connector clip and instructions. For a longer walkthrough, see our MOLY drop test procedure, step by step.
- Clean the surface.
- Apply one drop.
- Connect the 9V battery via the connector.
- Touch only the connector's negative (–) prong to the drop (not both prongs). This triggers the reaction.
- Read the result. The full result is visible within 30 seconds. BLACK and stays black = SS 202. RED and fades quickly = SS 304. RED and stays red = consistent with SS 316.
Keep the limits in mind. This is a screening indication only. A red reaction that stays points to molybdenum being present, which is consistent with 316 but is also seen with other molybdenum-bearing grades. The test cannot tell 304 from 304L or 316 from 316L, does not prove the exact grade or carbon content, and does not replace a certificate or a lab test. If you want to know why the colours appear, our molybdenum spot test science guide explains how it works. If the spot test points to a different grade than your certificate says, pause and query the supplier before you pay or install.
Frequently Asked Questions About EN 10204 3.1 vs 3.2
What's the actual difference between Type 3.1 and Type 3.2?
Both certificates give test results from the actual batch supplied. A 3.1 is validated by the manufacturer's authorised inspection representative, independent of production. A 3.2 adds the purchaser's authorised representative or an inspector designated by official regulations.
Which is legally required for government tenders in India?
We found no general Indian law that makes 3.1 or 3.2 compulsory for all government tenders. The tender's own specification decides, so read its material and inspection clauses. If it names 3.2 you need 3.2; if it asks only for an MTC or 3.1, 3.2 is not automatically required.
When exactly is 3.2 mandatory instead of 3.1?
Only when your purchase order, project specification, contract or a governing regulation asks for it. EN 10204 defines the documents but does not make 3.2 compulsory for any application by itself. Check the exact wording of your order.
Is 3.2 "better quality" steel, or just extra validation paperwork?
It is extra validation, not better steel. Grade and properties come from the material specification, and both certificates report results for the same kind of material. A 3.2 simply adds an independent second validator.
Who is the "independent third party" that signs a 3.2 certificate?
Under the standard, it is the purchaser's authorised inspection representative or an inspector designated by official regulations. In practice this is often an inspection agency such as Bureau Veritas, SGS, TÜV, Lloyd's Register or DNV, named in the order. The maker's own representative signs a 3.1 as well, so a 3.2 needs that outside signature in addition.
Do CPWD/PWD projects require 3.2, or accept 3.1?
We found no public CPWD or PWD rule that universally requires 3.2, and requirements can differ from tender to tender. Follow your own tender's wording and ask the engineer-in-charge if it is unclear.
Is 3.2 required for IBR (boiler regulation) jobs?
IBR work has its own statutory certification process, with forms endorsed by recognised inspecting authorities. We could not find a public provision naming EN 10204 3.2 as mandatory for every boiler job, though an order or project specification may ask for it. Confirm with your inspecting authority.
What's the cost/lead-time difference between getting 3.1 vs 3.2?
A 3.2 costs more because inspector time, travel and scheduling are involved, and it can add delay while the inspection is arranged. Published figures vary widely and we found no reliable India-wide benchmark. Ask for a written quotation covering cost and dispatch date.
Can a supplier legally substitute 3.1 when 3.2 was specified?
Not unless the buyer agrees. If the order specifies 3.2, a 3.1 does not meet the documentation requirement. Accept it only through a formal written approval from whoever set the specification; this is a contract matter, not legal advice.
Is 3.2 required for European export shipments?
Not automatically. It depends on the destination, the product, its intended use and the buyer's specification. For EU pressure equipment the documentation required varies with the equipment category and conformity route, so ask your European buyer what their order requires.
What's the difference between 2.1, 2.2, 3.1, and 3.2?
Type 2.1 is a declaration of compliance with no test results. Type 2.2 is a test report with non-specific results. Types 3.1 and 3.2 carry specific results from the supplied product, with 3.2 adding the independent second validator.
Does 3.2 change the actual steel chemistry, or just validation?
Only the validation. Chemistry and mechanical properties are those of the heat tested, identical on a 3.1 or a 3.2. The certificate type changes who confirms the results, not what the steel is.
How do I verify the third-party inspector named is genuine?
Check that the inspector or agency named is the one appointed in your order or required by regulation. Then confirm the details with that agency directly, using contact details from its official website rather than from the certificate. Our separate guide on verifying a mill test certificate goes deeper.
What should I ask for if only 3.1 is offered but I need 3.2?
Ask in writing before the order is finalised: can 3.2 be supplied, which agency or purchaser's representative will witness it, who pays, and how the dispatch date changes. Some inspection bodies offer verification of existing stock "to the intent of 3.2", but that is not a true 3.2 and the buyer must accept it beforehand.
Is EN 10204 mandatory Indian standard, or international/European?
EN 10204 is a European standard (EN). It is not an Indian standard or Indian law. It applies in India when a contract, export order or project specification asks for it.
How does EN 10204 apply to stainless vs carbon steel?
It applies the same way to all metallic products, stainless and carbon steel included. Grade limits come from the material specification; EN 10204 only describes the inspection document and who validates it. A 3.1 means the same on stainless sheet as on carbon steel plate.
Can a fabricator issue their own 3.1, or must it come from the mill?
A 3.1 comes from the manufacturer of the product it covers. A dealer or fabricator who only resells or cuts mill material normally passes on the mill's original certificate. If a fabricator manufactures a new product, whether they can issue one depends on what was made and what the order requires, so ask.
What happens if a project requires 3.2 but only 3.1 is provided?
The documentation does not meet the order, so the buyer can hold acceptance and ask for a compliant 3.2 or a formal approved deviation. The steel is not automatically defective, but the paperwork is non-conforming. Raising it early avoids delay and re-supply cost.
Are EN 10204 certificates recognized under BIS, or separate systems?
They are separate systems. BIS deals with Indian Standards and product certification, while EN 10204 describes the inspection document that goes with metallic products. One does not replace the other.
Is 3.2 required for pressure vessel/high-temp piping projects?
Not automatically. It depends on the governing code, the equipment category and the project specification. Read the specification and purchase order instead of assuming.
What should I check first if I don't understand a certificate I received?
First find the type printed on it (2.1, 2.2, 3.1 or 3.2) and compare it with your order. Then see who signed: one maker's quality signature points to 3.1, a second inspector's signature points to 3.2. Also match the heat number to the marking on the steel, because a certificate alone is necessary but not sufficient.
Can an EN 10204 certificate be forged like an MTC?
Any paper document can be falsified, and the EN 10204 label is no guarantee of authenticity. A 3.2 adds a second signer, which raises the effort but is not proof. Treat any certificate as necessary but not sufficient and check the physical material too.
Do sour-service applications (NACE MR0175) require 3.2 specifically?
NACE MR0175/ISO 15156 covers material suitability for sour (H2S) service, and we did not find that it mandates 3.2 by itself. Project or operator specifications often ask for 3.2 on critical items. This is unlikely to concern homeowners, small fabricators or scrap dealers.
Is there a simple way to explain 3.1 vs 3.2 to a non-technical buyer?
Think of a marksheet. A 3.1 is the school's own marksheet, signed by its examination department. A 3.2 is the same marksheet also countersigned by an outside examiner. The marks are the same; only the signatures differ.
How do EN 10204 certificates relate to India's own BIS system?
They answer different questions. BIS relates to whether a product and its maker meet an Indian Standard, while EN 10204 says who validated the test results for the batch supplied. They work side by side, not as substitutes.
Handed a 3.1 or 3.2 certificate for stainless steel you are about to pay for or install? Run a quick check on the piece itself with MOLY stainless steel testing liquid.
