Confirm EN 10204 3.1 wording during RFQ review
MTC 3.1 Guide for Forged Flange RFQs
This guide walks through a real EN 10204 3.1 inspection certificate issued by us on 25 February 2026 and validated by our authorised inspection representative, independent of production, so you can see exactly what a compliant MTC contains, how to verify each block, and what to state in the RFQ so the certificate matches your project.
Real certificate samples
EN 10204 3.1 Issued by us, 304L flanges Full-size scan (PNG)
EN 10204 3.2 Issued by TÜV SÜD, A350 LF2 flanges Full-size scan (PNG) See the full 3.2 document set
Customer and order references are redacted.
Key Points
Match heat number, material grade and product marking
Check chemical, mechanical, impact and NDT record needs
State third-party inspection requirements before quotation
Engineering Selection Notes
Most MTC guides describe certificates in the abstract. This one shows a real document: an EN 10204 3.1 inspection certificate issued by us on 25 February 2026 and validated by our authorised inspection representative, independent of production, for ten 304L reducing flanges. Only the customer name and order references are redacted - the technical content, stamps and signature blocks are exactly what buyers receive with a shipment.
The single most useful habit when reviewing a 3.1 is to read it against two references at once: the product marking (does the heat number match?) and the material standard (do the measured values sit inside the limits?). On this certificate the mill chemistry and the mechanical results both sit comfortably inside the printed limits, and the test method, revision and temperature are stated - which is what makes the values auditable rather than decorative.
Where buyers get hurt is scope, not forgery: a genuine 3.1 that simply does not cover the dimensional report, PMI or the impact test their project needed. The certificate defines what was tested; the RFQ defines what should be. That is why the checklist below front-loads document scope into the enquiry stage.
First-Hand Evidence
Two redacted certificate examples are shown below. The 304L 3.1 specimen has its customer and order references redacted. The LF2 3.2 specimen also redacts TÜV contact details, inspector names and signatures; its technical fields and the TÜV SÜD issuer identity remain visible.
Evidence 1
Redacted areas cover the customer name and order references only; all technical content is unedited.
Evidence 2
This order-specific specimen shows the document route used for one 3.2 order. It does not certify BLD as a manufacturer or establish 3.2 coverage for another product, grade, heat or order.
Evidence 3
The two certificate pages form one specimen. The separate TÜV inspection report is not reproduced here because it may only be quoted as its complete 11-page set.
Direct Answers with Evidence
What distinguishes a true EN 10204 3.1 document from a 3.2 document?
A 3.1 certificate is issued by the manufacturer and validated by its own authorized inspection representative who is independent of production. The redacted 3.2 contrast specimen is instead issued and signed by TÜV SÜD for one A350 LF2 CL1 order under the independently agreed validation route.
Evidence
- On the 304L 3.1 specimen: the certification statement, the QC inspection stamp and the authorized-representative signature block sit at the bottom of the document
- Every line item carries its heat number (SY2504B217) and test specimen number (26Y020122), which must match the marking on the flange
- The 3.2 contrast specimen identifies TÜV SÜD Beijing Branch as issuer on certificate 348229 and reports the order-specific results for LF2 heat 6A06260
Applies when
Applies to metallic products certified under EN 10204. If independent 3.2 validation is required, agree the route with the buyer and inspection body before production.
Limits
The 3.2 specimen covers one LF2 heat from one order. It does not certify BLD or all BLD products and must not be extrapolated to another order, heat, grade, product or service condition.
How do you verify a 3.1 certificate line by line?
Check four blocks in order: identity (heat number vs product marking), chemistry (measured vs standard limits), mechanicals (measured vs standard minimums), and process (heat treatment, standard revision, test method).
Evidence
- Chemistry on the specimen: C 0.020% against a 0.03% max, Cr 18.10% within 18.00-20.00%, Ni 8.01% within 8.00-13.00% - every measured value sits inside the printed limits
- Mechanicals per ASTM A370-24 at 20°C, transverse specimen: yield 264 N/mm² against a 170 minimum, tensile 565 N/mm² against 485, elongation 52% against 30, reduction of area 77% against 50, hardness 156/153/157 HBW
- Process block states solution annealing at 1040±10°C and the governing revision A182/A182M-25
Applies when
Numbers above are from certificate BLD-26-2-25-001 for heat SY2504B217; every heat gets its own measured values.
Limits
A 3.1 does not by itself cover dimensional reports, PMI, UT/MT/PT or third-party witness - those must be ordered separately and are listed as separate documents.
What must the RFQ state so the 3.1 matches your project?
State the certificate type (3.1 or 3.2), material standard with revision, heat treatment condition, any impact/hardness/PMI/NDT requirements, and the language or format your end user expects - before price is agreed.
Evidence
- The specimen shows what is only there because the order asked for it: solution-annealing temperature, forging ratio, transverse test direction
- Our lab issues certificates in English as standard; Russian-format passports are available for CIS projects
Applies when
Best stated in the RFQ line items; adding certification requirements after production may be impossible if extra test material was not reserved.
Limits
Do not assume an existing 3.1 certificate can be reissued as 3.2. Agree the required validation route, records and acceptance with the buyer and inspection body before production.
Source Basis
- LRQA - EN 10204 Type 3.2 certification services - inspection-body overview of Type 3.2 validation routes and the need to agree the route before manufacture
- ASTM A182/A182M - forged flange material specification (scope page) - governing standard and revision quoted on the specimen certificate
Measured values vs specification limits - taken from the certificate above (heat SY2504B217, 304L)
| Property | Limit printed on the certificate | Measured value | Verdict |
|---|---|---|---|
| C | max 0.03% | 0.020% | within limit |
| Si | max 1.00% | 0.38% | within limit |
| Mn | max 2.00% | 1.34% | within limit |
| P | max 0.045% | 0.031% | within limit |
| S | max 0.030% | 0.001% | within limit |
| Cr | 18.00-20.00% | 18.10% | within range |
| Ni | 8.00-13.00% | 8.01% | within range |
| N | max 0.10% | 0.066% | within limit |
| Yield strength Rp0.2 (ASTM A370-24, 20°C, transverse) | min 170 N/mm² | 264 N/mm² | passes with margin |
| Tensile strength Rm | min 485 N/mm² | 565 N/mm² | passes with margin |
| Elongation A | min 30% | 52% | passes with margin |
| Reduction of area Z | min 50% | 77% | passes with margin |
| Hardness | - | 156 / 153 / 157 HBW | reported (three readings) |
Buyer question, required evidence and limits
| Buyer question | Evidence to check | What it can establish | What it cannot establish |
|---|---|---|---|
| Does this certificate belong to the supplied item? | Match the heat number and product identity on the MTC to the physical marking and order line | Traceability between that marked item, heat and certificate when the identifiers agree | Material suitability for a different item, heat, grade or service |
| Do the reported values meet the stated material limits? | Compare each measured chemistry and mechanical value with the printed standard limits and revision | Whether the reported results for that specimen fall within those listed limits | Results for an untested heat, duplex grade or other product |
| Does MTC 3.1 include every project inspection? | Check the RFQ and document index for dimensional, PMI, ferrite, UT, MT, PT or impact reports | Only the tests and records that are explicitly identified in the certificate or attached reports | Any separate inspection or witness activity that is not named |
| Is independent validation required? | Check whether the purchase specification calls for EN 10204 3.2 or a named third-party hold point | Which validation route the buyer requested before production | That a 3.1 document has independent third-party validation |
How to read the certificate above, block by block
| Block | What our 3.1 certificate prints there | What to check |
|---|---|---|
| Header | 'Inspection Certificate (EN 10204-3.1)', Shanxi Baolongda Forging Co., Ltd., certificate No. BLD-26-2-25-001, date of report 2026.02.25 | The document type is the one your order asked for, and the issuer is the manufacturer |
| Order and process data | Specification compliance ASTM A182/A182M-25, material 304L, solution heat treatment 1040±10 °C, hot forging temperature 850-1150 °C, forging ratio ≥3.5 | Standard and revision, grade and heat-treatment condition match the purchase order |
| Content of delivery | Item 2, quantity 10, heat SY2504B217, specimen 26Y020122 | Heat number and quantity match the marking on the flanges and the packing list |
| Chemistry | Min and max rows, then the measured row for heat SY2504B217: C 0.020, Si 0.38, Mn 1.34, P 0.031, S 0.001, Cr 18.10, Ni 8.01, N 0.066 (%) | Every measured value sits inside its printed limit |
| Mechanical properties | ASTM A370-24, Φ12.5 mm specimen, 50 mm gauge length, direction Tr, 20 °C: Rp0.2 264, Rm 565 N/mm², A 52%, Z 77%, hardness 156/153/157 HBW | Test standard, direction and temperature are the ones your specification requires, and each value meets its minimum |
| Impact test | Columns for three single Charpy values and their mean on a 10×10×55 mm ISO-V specimen, with a temperature field; blank on this certificate | If your order needs an impact test, the three values and the test temperature are filled in - a blank block means no result is reported |
| Closing block | Visual inspection, dimensional check and surface crack inspection: 'Without Complaint'; certification statement; date 2026/2/25; manufacturer's authorized inspection representative and quality-inspection stamp | The certificate is validated by the authorized inspection representative, not only printed |
MTC 3.1 Data Buyers Should Check
| Certificate field | Required evidence | Common mismatch | Buyer action |
|---|---|---|---|
| Heat number | Same heat on forging, marking and MTC | Part marking does not match certificate | Request heat traceability photo/report |
| Material grade | Exact ASTM/EN/GOST grade and condition | A105 supplied where A105N is required | Confirm before production |
| Chemical analysis | C, Mn, Si, P, S and alloy elements | Grade family looks similar but chemistry differs | Review against material standard |
| Mechanical test | Tensile, yield, elongation, reduction where applicable | Missing low-temperature impact record | Add impact requirement in RFQ |
| Heat treatment | Normalizing, Q+T, solution annealing or stress relief | Treatment not listed on MTC | Require heat-treatment record |
| Inspection reference | Dimensional, PMI, UT, MT/PT if specified | Inspection requested after quotation | List inspection scope in first RFQ |
Practical Checklist
- Required certificate type, such as EN 10204 3.1
- Material grade, heat number traceability and product marking
- Chemical composition and mechanical test values required by the standard
- Heat treatment record, impact test or hardness test if required
- Dimensional report, PMI, UT, MT or PT if required by the project
- Third-party inspection witness, review or release note
- Language, stamp or document format required by your project or end user
Common RFQ Mistakes
- Asking for MTC 3.1 after the order is already priced without documents
- Not matching heat numbers between products, marks and certificates
- Forgetting impact test requirements for low-temperature projects
- Assuming third-party inspection is included without stating it in the RFQ
- Treating a certificate PDF as enough when the project also needs dimensional or NDT reports
FAQ
What is an EN 10204 3.1 material test certificate?
A 3.1 MTC is issued by the manufacturer and validated by its own inspection department independent of production. It reports the actual chemical composition and mechanical test results of the delivered heat, linked to the heat number marked on the flange.
What is the difference between MTC 3.1 and 3.2?
3.1 is validated by the manufacturer's authorized inspection representative independent of production. For 3.2, the order must define the required independent validation route and the buyer or inspection body's acceptance requirements before production.
What should a buyer check on a received 3.1 certificate?
Match the heat number on the certificate against the marking on the product, check chemistry and mechanical values against the material standard, and confirm heat treatment condition, dimensions standard and any required impact or hardness tests are reported.
Does every forged flange order need a 3.1 MTC?
Most pressure-service and project orders require it, and it is standard practice for export flanges. Requesting 3.1 in the RFQ costs little; adding certification after production may be impossible if traceability was not maintained.
Does a 3.1 certificate list single measured values, or only 'passed'?
Single measured values. A 3.1 states the results of specific inspection on the delivered products, so it prints the actual number for each element and test next to its limit. Where a test has several readings each one is listed - our certificate shows hardness as 156/153/157 HBW, and its impact block has a column for each of three Charpy values plus the mean. A blank column means no result is reported, not that the test passed.
What do the test direction and test temperature on an MTC mean?
Direction says how the test specimen was cut relative to the forging; temperature says the condition the value applies to. Our certificate reads direction Tr (transverse) at 20 °C to ASTM A370-24. A value at 20 °C is not a value at design temperature, so if your design code needs an elevated-temperature tensile or proof-strength value, or a set specimen direction, write it in the RFQ so the test is planned before production.
Can I see a sample MTC 3.1 or 3.2 for flanges?
Yes, both are on this page. The 3.1 sample is our certificate BLD-26-2-25-001 for ten 304L reducing flanges; the 3.2 sample is TÜV SÜD certificate 348229 for one A350 LF2 CL1 weld neck flange order. Only customer and order references are redacted on the 3.1, and on the 3.2 also the TÜV contact details, inspector names and signatures.
Are MTC 3.1, 3.1 MTC and EN 10204 3.1B the same thing?
MTC 3.1 and 3.1 MTC are two ways of writing the same EN 10204 type 3.1 inspection certificate. 3.1.B is the name the older 1991 edition of EN 10204 used; the current edition calls it 3.1. If a project specification still says 3.1.B, confirm with the buyer that a 3.1 certificate to the current edition is acceptable.
What does 'Tr' or 'L' mean on a flange MTC?
They give the direction of the test specimen: L is longitudinal and Tr is transverse. Our certificate prints this legend under the mechanical table, together with T for top, B for bottom and RT for room temperature.
Author & Verification
Written by: Tom Fan, Sales Director, BLD Forge Direct (Shanxi Baolongda Forging Co., Ltd.)
Reviewed by: BLD QC Engineering Team - in-house laboratory, CNAS L24083
Last verified: 2026-07-17
Revision log
- 2026-10-10 - Added a block-by-block reading table taken directly from the 3.1 specimen and five FAQs on single measured values, test direction and temperature, sample certificates, the old 3.1.B name and the L/Tr legend. They answer the questions buyers were searching for when this guide appeared in Google and Bing results.
- 2026-09-23 - Added a redacted two-page EN 10204 3.2 certificate issued by TÜV SÜD as a bounded 3.1-versus-3.2 contrast. The example is one A350 LF2 CL1 order and does not establish certification or results for other grades, heats or orders.
- 2026-07-17 - Added an annotated real 3.1 certificate specimen (issued 2026-02-25, 304L reducing flanges; customer identifiers redacted), the measured-vs-limit data table taken from that certificate, direct-answer evidence units and this accountability block.
- 2026-07-09 - RFQ checklist and FAQ baseline version.
Send your RFQ or drawing directly to BLD Forge Direct.
Email quote@bldforgedirect.com with standard, drawing, material, quantity and inspection requirements.