Many buyers ask for EN 10204 3.1 or 3.2 certificates when buying stainless steel tubes.
But not every buyer knows the real difference.
This difference is important.
If the wrong certificate type is selected, the project may face delay, extra cost, or end-user rejection.
For stainless steel tube projects, a stainless steel Mill Test Certificate is not just a document.
This guide explains the difference between EN 10204 3.1 and EN 10204 3.2 certificates. It also explains when buyers should request each type.
What Is EN 10204?
EN 10204 is a European standard for inspection documents.
It is used for metallic products, such as:
- Stainless steel tubes
- Seamless pipes
- Welded pipes
- Flanges
- Pipe fittings
- Plates
- Bars
- Forged parts
The certificate shows whether the product meets the purchase order and required standard.
For stainless steel tube projects, EN 10204 certificates may include:
- Material grade
- Product standard
- Heat number
- Size
- Quantity
- Chemical composition
- Mechanical properties
- Heat treatment
- Test results
- Inspection status
- Signature and stamp
The certificate helps buyers confirm that the supplied material matches the order.
Common EN 10204 Certificate Types
EN 10204 includes different certificate types.
The most common types are 2.1, 2.2, 3.1, and 3.2.
| Certificate Type | What It Means | Test Results | Independent Witness |
|---|---|---|---|
| 2.1 | Declaration of compliance | No test results | No |
| 2.2 | Test report with non-specific test results | Yes, but not from the exact supplied batch | No |
| 3.1 | Inspection certificate from manufacturer | Yes, from specific inspection | Normally no third-party witness |
| 3.2 | Inspection certificate with independent verification | Yes, from specific inspection | Yes |
For most international stainless steel tube orders, buyers usually ask for 3.1 or 3.2.
What Is an EN 10204 3.1 Certificate?
An EN 10204 3.1 certificate is an inspection certificate issued by the manufacturer.
It confirms that the supplied material meets the order requirement.
It also includes specific test results from the actual material or batch.
A 3.1 certificate is usually signed by the manufacturer’s authorized inspection representative.
This representative should be independent from the production department.
A 3.1 certificate may include:
- Heat number
- Material grade
- Product standard
- Size
- Quantity
- Chemical composition
- Mechanical properties
- Heat treatment record
- Required test results
- Manufacturer stamp and signature
For many normal industrial orders, a 3.1 certificate is enough.
What Is an EN 10204 3.2 Certificate?
An EN 10204 3.2 certificate gives a higher level of control.
It includes specific test results, like a 3.1 certificate.
But it also requires independent verification.
This independent verification may be done by:
- Buyer’s inspector
- Third-party inspection company
- Officially appointed inspection body
- Classification society, if required by the project
A 3.2 certificate is often used for critical projects. In many cases, buyers also need third-party inspection support before shipment.
These may include:
- Oil and gas projects
- Pressure equipment
- Marine projects
- Offshore projects
- Power plants
- Chemical plants
- Heat exchanger projects
- End-user approved projects
A 3.2 certificate takes more time and costs more than a 3.1 certificate.
This is because the inspector must review or witness the material, tests, documents, and traceability.
EN 10204 3.1 vs 3.2: Main Difference
The main difference is independent inspection.
A 3.1 certificate is issued by the manufacturer.
A 3.2 certificate includes independent verification.
| Item | EN 10204 3.1 | EN 10204 3.2 |
| Issued By | Manufacturer’s authorized inspection representative | Manufacturer plus buyer’s inspector or third-party inspector |
| Test Results | Specific inspection results | Specific inspection results with independent verification |
| Third-Party Witness | Normally not required | Required |
| Cost | Lower | Higher |
| Lead Time | Faster | Longer |
| Common Use | Standard industrial orders | Critical projects and end-user required orders |
| Inspection Level | Normal | Higher |
| Best For | Regular stainless steel tube orders | Pressure, marine, oil and gas, or high-risk projects |
If the project specification says 3.2, buyers should not accept 3.1 without written approval.
When Should Buyers Request 3.1?
A 3.1 certificate may be suitable for many standard orders.
Buyers may request 3.1 for:
- General stainless steel tube orders
- Heat exchanger tubes
- Boiler tubes
- Condenser tubes
- Process piping
- Industrial projects
- Non-critical service
- Orders without third-party witness requirement
A 3.1 certificate is common because it gives specific test results from the supplied material.
It is usually faster and more cost-effective than 3.2.
When Should Buyers Request 3.2?
A 3.2 certificate should be requested when the project needs independent verification.
Buyers may request 3.2 for:
- Oil and gas projects
- Offshore projects
- Marine projects
- Pressure equipment
- Power plants
- Critical heat exchangers
- End-user specified orders
- EPC projects
- Projects with third-party inspection requirement
- Projects where material traceability is very important
If the end user requires 3.2, buyers should confirm it before production.
If 3.2 is added after production, it may cause delay or extra cost.
Why 3.2 Costs More Than 3.1
A 3.2 certificate costs more because more work is needed.
The inspection company may need to check:
- Purchase order
- Material standard
- Heat number
- Product marking
- MTC
- Chemical composition
- Mechanical test results
- NDT reports
- Dimensional inspection
- Packing
- Traceability records
The inspector may also need to witness tests.
These steps take time.
This is why buyers should confirm 3.2 requirements before placing the order.
What Should Be Checked on a 3.1 or 3.2 Certificate?
Buyers should not only check the certificate type. They should also know how to read a stainless steel tube MTC before accepting the material.
They should also check the certificate content.
| Certificate Section | What to Check |
| Manufacturer Information | Company name, certificate number, issue date |
| Buyer / PO Information | Purchase order number and project reference |
| Product Description | Tube type, size, wall thickness, length, quantity |
| Material Grade | 304L, 316L, 321, 2205, 2507, Alloy 825, etc. |
| Standard | ASTM, ASME, EN, DIN, or project standard |
| Heat Number | Must match tube marking |
| Chemical Composition | Must meet the material grade requirement |
| Mechanical Properties | Yield strength, tensile strength, elongation, hardness |
| Test Results | PMI, hydrostatic, ET, UT, flattening, flaring, if required |
| Signature / Stamp | Must match the certificate type |
| Third-Party Confirmation | Required for 3.2 |
A certificate is only useful if the information matches the supplied material.
Heat Number and Traceability
Heat number is one of the most important parts of the certificate.
The heat number links the tube to the original steel heat or batch.
Buyers should check that the heat number appears on:
- MTC
- Tube marking
- Bundle label
- Packing list
- Inspection report
- Third-party inspection report, if required
If the heat number does not match, traceability becomes weak.
For critical projects, this may cause rejection.
Common Mistakes Buyers Should Avoid
Buyers should avoid these mistakes:
- Asking for 3.2 after production is finished
- Accepting 3.1 when the project requires 3.2
- Not checking the heat number
- Not checking the material grade
- Not checking chemical composition
- Not checking mechanical properties
- Not checking required test reports
- Not confirming third-party inspection before order
- Not checking whether the inspector is accepted by the end user
- Not matching the certificate with product marking
Most certificate problems can be avoided before production.
Buyer Checklist Before Ordering
Before placing an order, buyers should confirm the certificate requirement clearly.
Certificate Requirement Checklist
- Is EN 10204 required?
- Is 3.1 enough?
- Is 3.2 required?
- Who should issue or witness the 3.2 certificate?
- Which third-party inspection company is accepted?
- Is BV, SGS, TUV, LR, ABS, DNV, or another inspector required?
- Should the inspector witness testing?
- Is PMI required?
- Is hydrostatic test required?
- Is ET or UT required?
- Is dimensional inspection required?
- Is packing inspection required?
- Should the certificate show the project name?
- Should the certificate show the PO number?
- Should the certificate show heat number and batch number?
- Are original documents required before shipment?
A clear certificate requirement helps reduce delay and cost.
3.1 vs 3.2 for Stainless Steel Tube Orders
For stainless steel heat exchanger tubes and other stainless steel tube orders, both 3.1 and 3.2 can be used.
The right choice depends on the project.
| Project Type | Common Certificate Choice |
| General industrial tubing | 3.1 |
| Standard heat exchanger tubes | 3.1 or 3.2, depending on project |
| Boiler tubes | 3.1 or 3.2, depending on pressure and end user |
| Marine projects | Often 3.2 or class witness |
| Oil and gas projects | Often 3.2 if required by EPC or end user |
| Offshore projects | Often 3.2 |
| Critical pressure equipment | Often 3.2 |
| Low-risk general order | Usually 3.1 |
If the project document is not clear, buyers should ask the end user before ordering.
How DLSS Supports 3.1 and 3.2 Certificate Requirements
DLSS supplies stainless steel, duplex, super duplex, nickel alloy, copper nickel, and titanium tubes for industrial projects. A clear DLSS quality control process helps buyers check material grade, heat number, testing, documents, and packing before shipment.
We can support certificate and inspection requirements such as:
- EN 10204 3.1 certificate
- EN 10204 3.2 inspection support
- MTC review
- Heat number traceability
- PMI testing
- Hydrostatic testing
- Eddy current testing
- Ultrasonic testing
- Dimensional inspection
- Surface inspection
- Packing inspection
- Third-party inspection coordination
DLSS can work with third-party inspection companies when required by the project.
These may include BV, SGS, TUV, LR, ABS, DNV, or other project-approved inspection companies.
Important Note Before Production
Buyers should confirm the certificate type before production.
This is especially important for 3.2 certificate orders.
Why?
Because the inspector may need to witness tests or review material before shipment.
If the buyer asks for 3.2 after the goods are already finished or packed, it may not be possible to complete the inspection in the correct way.
This can cause:
- Delay
- Extra inspection cost
- Re-testing
- Repacking
- Document problem
- End-user rejection
The safest way is to write the certificate type clearly in the purchase order.
FAQ
What is EN 10204?
EN 10204 is a standard for inspection documents for metallic products. It defines certificate types such as 2.1, 2.2, 3.1, and 3.2.
What is an EN 10204 3.1 certificate?
An EN 10204 3.1 certificate is issued by the manufacturer. It includes specific test results from the supplied material or batch.
What is an EN 10204 3.2 certificate?
An EN 10204 3.2 certificate includes specific test results and independent verification by the buyer’s inspector, third-party inspector, or appointed inspection body.
Is 3.2 better than 3.1?
3.2 gives a higher level of independent verification. But it is not always needed. The right choice depends on the project requirement.
Why does 3.2 cost more?
3.2 costs more because it needs independent inspection, document review, traceability checks, and sometimes test witnessing.
Can 3.1 be changed to 3.2 after shipment?
Usually, this is difficult or not possible in the correct way. Buyers should confirm 3.2 before production and inspection.
Which certificate is needed for stainless steel tubes?
Most normal orders use 3.1. Critical projects, oil and gas, marine, offshore, pressure equipment, or end-user specified projects may need 3.2.
Can DLSS provide 3.2 certificate support?
Yes. DLSS can support EN 10204 3.2 inspection coordination when it is confirmed before production and accepted by the project requirement.
Conclusion
EN 10204 3.1 and 3.2 certificates are both important for stainless steel tube projects.
The main difference is independent verification.
A 3.1 certificate is issued by the manufacturer and includes specific test results.
A 3.2 certificate includes independent inspection or witness by the buyer’s inspector, third-party inspector, or appointed inspection body.
For normal industrial tube orders, 3.1 may be enough.
For critical projects, pressure equipment, oil and gas, marine, offshore, or end-user required projects, 3.2 may be needed.
Before ordering, buyers should confirm the certificate type, inspection company, test requirements, heat number traceability, and document format.
DLSS can support stainless steel tube orders with MTC, EN 10204 3.1 certificate, EN 10204 3.2 inspection support, third-party inspection, and full document traceability.
If you need stainless steel tubes with EN 10204 3.1 or 3.2 certificate, send us your material grade, standard, size, quantity, inspection requirement, and project document. Our team will help review the certificate requirement before quotation.
