A mill test certificate (MTC) is the steel's birth certificate: it proves the exact heat you received has the chemistry and mechanical properties your order specified. Insist on EN 10204 type 3.1 (mill-issued, actual results), match the heat number on the certificate to the stencils on the material, and compare the values to the standard's limits. For critical orders add third-party inspection (SGS/BV/TUV) or a type 3.2 countersignature. Nikasteel supplies EN 10204 3.1 MTCs with every order, cross-checked against heat numbers before shipment.
Every legitimate steel shipment comes with a mill test certificate — and most trading disputes start when buyers don't read it. Here is how to read one properly, spot the red flags, and use it to protect your payment.
The Three Certificate Types (EN 10204)
| Type | Issued by | Based on | Use it when |
|---|---|---|---|
| 2.1 | Mill | Declaration of compliance only — no test results | Never, for structural steel |
| 2.2 | Mill | Non-specific test results (from a parent batch) | Low-risk non-structural items |
| 3.1 ✅ | Mill's independent inspection dept. | Actual results for the delivered heat/batch | The default for structural steel, plates, coils, pipes |
| 3.2 | Mill + third party (TUV/BV/SGS) | Actual results, countersigned on site | Pressure vessels, oil & gas, offshore, critical projects |
If a supplier offers only a 2.1 or 2.2 for structural material, treat it as a warning sign — either the material has no certified origin or the "mill" is not a mill at all.
What Each MTC Field Means
A 3.1 certificate usually contains these blocks. Check them in this order:
- Mill name & certificate number. The issuing plant (e.g. Tangshan, Maanshan group mills). Keep it for traceability.
- Product description. Product form (beam/plate/coil), dimensions, length, and the delivery condition (hot-rolled, normalized…).
- Standard & grade. Must match the proforma invoice exactly — e.g. "EN 10025-2 S355JR" or "ASTM A572 Gr50". A mismatch here is dispute #1.
- Heat number (heat/batch number). The fingerprint of the melt. Every bundle and every plate carries this number stenciled or tagged — it must match the MTC.
- Chemical composition. C, Si, Mn, P, S and alloys, in %. Compare each value to the standard's limits (not just to the nominal value).
- Mechanical properties. Yield strength (ReH / YS), tensile strength (Rm / TS), elongation (A), and impact energy (KV) if applicable — each with the sample orientation and test temperature.
- Declaration & signature. The EN 10204 3.1 statement, inspector name, date, and the mill's stamp. Unsigned PDFs are worth nothing.
Worked Example: S355JR Beam MTC
| MTC line | Your certificate shows | EN 10025-2 limit | Verdict |
|---|---|---|---|
| Grade / standard | S355JR — EN 10025-2 | — | Matches PI ✅ |
| Carbon (C) | 0.17 % | ≤ 0.24 % | Pass ✅ |
| Sulfur (S) | 0.020 % | ≤ 0.035 % | Pass ✅ |
| Yield ReH (≤16 mm) | 375 MPa | ≥ 355 MPa | Pass ✅ |
| Tensile Rm | 510 MPa | 470–630 MPa | Pass ✅ |
| Elongation A | 22 % | ≥ 22 % (long transverse) | Pass ✅ |
| Impact KV (20 °C, JR) | 47 J | ≥ 27 J | Pass ✅ |
Values sitting exactly at a limit (yield 355.0, elongation 22.0) deserve a second look — real heats vary; textbook values suggest a "recycled" template.
How to Verify: 5 Checks Before Paying the Balance
- Heat-number matching. During loading supervision, photograph the stencils/tags on the material and match them to the MTC list. This single check kills most substitution fraud.
- Document check. Grade, standard, sizes, quantities and tolerances on the MTC = PI. One mismatch → stop and ask.
- Values vs standard. Compare chemistry and mechanics against the published limits (as above), not against memory.
- Third-party inspection. For high-value or critical orders, have SGS/BV/TUV witness testing or verify at the warehouse, and issue their own report.
- Sample re-test. The strongest proof: an independent lab re-tests a coupon from the delivered material. Cost is minor compared to the cargo value.
Nikasteel's four-step QC — mill selection → certificate cross-check → pre-shipment inspection → loading supervision with photos/videos — is documented here and applies to every order, from 5-ton trials to annual contracts.
FAQ — Buyers Ask
What is an EN 10204 3.1 certificate?
A mill test certificate with actual test results for the delivered heat, issued by the mill's independent inspection representative. The default for structural steel.
3.1 vs 3.2 — which do I need?
3.1 for normal structural orders; 3.2 (third-party countersigned) for pressure vessels, oil & gas and offshore work. We arrange both.
Can MTCs be faked?
Yes — edited PDFs are the most common fraud. Defenses: heat-number matching at loading, third-party inspection, sample re-testing.
Do you provide MTCs with every order?
Yes — EN 10204 3.1 with every order, cross-checked against heat numbers. SGS/BV/TUV and 3.2 countersignature on request.
What if the material fails inspection?
With inspection booked before shipment, rejected material is replaced before it ever leaves China — that is exactly why we supervise loading.
MTC vs COC — what's the difference?
A certificate of conformity states the product meets a standard; an MTC proves it with actual heat-specific test data. Always insist on the MTC.
About the Source
Foshan Nikasteel International Trade Co., Ltd. — a China-based steel exporter in Foshan, Guangdong, supplying structural steel, plates and coated coils to 50+ countries since 2016, with EN 10204 3.1 mill certificates on every order and SGS/BV/TUV third-party inspection on request.
- 📧 kelly@nikasteel.com · WhatsApp/Phone: +86 191 5745 8011
- 📍 Foshan City, Guangdong Province, China · Mon–Sat 8:30–18:30 (GMT+8)
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Last updated: October 2026.