What is a mill test certificate?
Two companion resources dig into details past this capability page. The EN 10204 mill test certificate standard defines each document type, while MTC, NDT and PMI testing covers what each test measures metallurgically. This page lays out what Nandini Steel actually issues.
EN 10204 inspection-document types we issue
EN 10204 sets out four inspection document types. What actually matters to a specifier is who signs off on the document, and whether that person stands apart from production. Nandini Steel includes a type 3.1 certificate with every order as a matter of course. A type 3.2 certificate, countersigned by an independent third-party inspector or by the purchaser's own inspector, is available on request.
| Type | Name | Content | Validated by | Independent of production? |
|---|---|---|---|---|
| 2.1 | Declaration of compliance | Statement that the product meets the order; no test results | Manufacturer | No |
| 2.2 | Test report | Statement of compliance with results from non-specific (routine) testing | Manufacturer | No |
| 3.1 | Inspection certificate | Results of specific testing on the delivered heat | Manufacturer's authorized inspection representative | Yes, independent of the production department |
| 3.2 | Inspection certificate | Results of specific testing on the delivered heat | Manufacturer's representative plus an independent/third-party or purchaser's inspector | Yes, countersigned by an independent inspector |
3.1 vs 3.2: which do you need?
For most stainless, nickel-alloy and PVQ orders, a type 3.1 certificate gets the job done. The testing is specific to your heat, and an inspection representative independent of the people who made the material validates it. Step up to 3.2 when your client, your code, or your project specification calls for a second signature from a nominated third party, such as TÜV SÜD, Bureau Veritas, DNV or SGS, or from your own inspector. That's typical on pressure-vessel, oil & gas and export-critical work. Not sure which your spec requires? Our walkthrough on how to read a mill test certificate shows exactly where the validating signature sits on each type.
What's on every Nandini mill test certificate
Each certificate matches a documented set of results to one specific heat. Below, you'll find what typically appears on a 3.1 or 3.2 certificate we issue. We add supplementary tests when your specification requires them.
| Section | What it records |
|---|---|
| Heat / cast number | The unique identifier that links the material to this certificate, die-stamped on the product |
| Ladle (cast) chemical analysis | Element-by-element composition against the grade specification |
| Mechanical properties | Tensile strength, 0.2% proof (yield) strength, elongation, hardness; Charpy impact where required |
| Heat-treatment condition | e.g. solution-annealed (stainless / nickel alloys) or normalized (PVQ plate) |
| Dimensions & quantity | Thickness, width, length / diameter and the quantity certified |
| Standard & grade conformance | ASTM / ASME / EN standard plus UNS and Werkstoff (WNr) designations |
| Surface condition & marking | Finish and the marking applied to the material |
| Supplementary tests | IGC (ASTM A262), PMI, UT, RT, hydrostatic or HIC results when specified |
| Manufacturer's declaration | Signature of the authorized inspection representative (plus the third-party countersignature on 3.2) |
Heat-number traceability: material to certificate
Traceability drives this whole document. The heat (or cast) number gets die-stamped onto the plate, coil, pipe or bar, and then repeated on the certificate, so any piece in your yard can be traced back to the exact ladle analysis and mechanical results that qualify it. That stamped-to-certificate chain lets an inspector confirm, without re-testing, that the material in front of them matches the heat the MTC describes. We walk through the full chain, from pour to delivery, under material traceability. For cut or multi-piece orders, the original marking carries over so each piece stays identifiable to its heat.
Additional testing & reports we furnish
Beyond the base certificate, we can also put together the supplementary reports that a corrosion-resistant or pressure-vessel spec usually calls for. Which tests apply comes down to grade, form and service.
Positive material identification (PMI)
PMI checks, by running a spectrometer on the actual item, that the heat matches the UNS or grade claimed on the certificate. It's the fastest guard against a mixed-up grade turning up at receiving inspection. The method pays off most when your spec calls for a specific alloy, say 904L or Incoloy 825.
Non-destructive testing: UT and RT
Ultrasonic testing, or UT, checks plate and heavier sections for internal discontinuities. Welds and pipe get radiographic testing, RT, instead. Which method applies depends on the form in question and whatever code governs it.
Hydrostatic test
For pipe and fittings, a hydrostatic test checks integrity under pressure. The test pressure and hold time both go on the report.
Intergranular corrosion (IGC) per ASTM A262
Sensitization is chromium-carbide precipitation along grain boundaries. It happens between 425 and 815 °C, and you can stop it by choosing a low-carbon ("L") grade, a stabilized grade (321/347), or by solution annealing correctly. An IGC test under the relevant ASTM A262 practice picks up susceptibility, and mills often run it on 304L, 316L and 904L certificates. See intergranular corrosion (ASTM A262).
Charpy impact (PVQ low-temperature)
For low-temperature pressure vessels, normalizing improves A516 Gr 70, and the plate certificate reports Charpy impact values at the design temperature rather than relying on assumptions drawn from as-rolled material.
HIC per NACE TM0284 and sour-service documentation
For sour (wet H₂S) service, the HIC-tested variant of A516 Gr 70 resists hydrogen-induced cracking and must be tested per NACE TM0284. Incoloy 825 stands up to sour service and conforms to NACE MR0175 / ISO 15156; the qualified condition and hardness are documented right on the certificate. See our sour-service documentation notes and the NACE MR0175 / ISO 15156 standard.
| Supplementary test | Governing standard | Typical application |
|---|---|---|
| Intergranular corrosion (IGC) | ASTM A262 | 304L / 316L / 904L, sensitization check |
| Hydrogen-induced cracking (HIC) | NACE TM0284 | A516 Gr 70 NACE-HIC plate |
| Sour-service hardness / condition | NACE MR0175 / ISO 15156 | Incoloy 825, sour-gas duty |
| Positive material identification (PMI) | Spectrometric verification | Grade / UNS confirmation on any item |
| Ultrasonic / radiographic (UT / RT) | Per governing product code | Plate (UT) · welds and pipe (RT) |
| Hydrostatic test | Per governing product code | Pipe and fittings |
Grades & forms we certify
Every grade and form we stock ships with a mill test certificate. The default is EN 10204 3.1, though we can upgrade to 3.2 on request. The certificate lists the governing standard along with the equivalent UNS, Werkstoff, and JIS designations, see the UNS / Werkstoff / JIS cross-reference.
| Grade | Forms | Governing standard | Default MTC |
|---|---|---|---|
| 304 / 304L | Sheet, plate, coil | ASTM A240 / ASME SA-240 | 3.1 (3.2 on request) |
| 316 / 316L | Sheet, plate, coil | ASTM A240 / ASME SA-240 | 3.1 (3.2 on request) |
| 904L | Sheet, plate, coil | ASTM A240 / ASME SA-240 | 3.1 (3.2 on request) |
| Incoloy 825 | Sheet, plate, coil | ASTM B424 / ASME SB-424 | 3.1 (3.2 on request) |
| A516 Gr 70 | Plate (incl. normalized, NACE-HIC) | ASTM A516 / ASME SA-516 + ASTM A20 | 3.1 (3.2 on request) |
Pipe, pipe-fittings, forged fittings, flanges, round bars and fasteners all carry the same certification. Flat-product standards get called out by number on the certificate too: ASTM A240 / ASME SA-240, ASTM B424 for Incoloy 825, and ASTM A516 / ASME SA-516 for PVQ plate.
Genuine mill material & authorized-mill MTC provenance
A certificate's only as trustworthy as the metal it describes. Nandini Steel sources genuine mill plate and long products from established producers: Aperam, Outokumpu, Jindal, POSCO, Nippon Steel and JFE. The mill's own test certificate stays with the heat the whole way through. Since the MTC comes straight from the producing mill and ties to the stamped heat number, what you get is first-party test data, not some reworded endorsement from a stockist. The purchase order needs to name the alloy correctly. Incoloy 825 (UNS N08825), for instance, often gets mis-ordered as "Inconel 825." Matching the PO to the MTC designation keeps receiving inspection from turning into a dispute.
Our certifications & third-party inspection partners
Nandini Steel runs its quality management system under ISO 9001:2015, certificate no. 1283438, issued by Unitas Certification Services (UCS-UK) and valid through 11 January 2028. The certified scope takes in manufacture, import and export of stainless, carbon and alloy-steel pipe, fittings and flanges, plus stockholding of stainless and carbon-steel rods, sheets and plates. 904L, Alloy 28, Incoloy 800 and Hastelloy plates get a specific mention on the certificate as a named specialty. When clients need type 3.2 work or nominate their own inspection, we bring in third-party agencies such as TÜV SÜD, Bureau Veritas, DNV, SGS and ABS. You'll find more on our ISO 9001:2015 certification page, and our quality assurance process is laid out separately. For background on the company, there's the about Nandini Steel page.
How to request & verify an MTC
Requesting and checking a certificate is a short, repeatable process:
RFQ stage, grade, form, standard and any supplementary tests you need (IGC, PMI, UT/RT, hydrostatic, HIC, NACE MR0175), state them with your inquiry, and say whether you want type 3.1 or 3.2.
Certificate on dispatch. The mill test certificate ships with the material; everything is held ex-stock, so dispatch happens straight away.
Check the heat number. Compare the heat or cast number stamped on the material with the number printed on the certificate.
Check it against the standard. Make sure the reported chemistry and mechanicals meet the grade specification, and confirm any required supplementary test results are there.
Hold onto the export set. For orders going abroad, the certificate travels with the standard export package. See export documentation & Incoterms for more on this.
A mill test certificate sits at the center of procurement for pressure vessels and sour-service work in particular, see pressure-vessel steel and oil & gas (sour service). Want to start a request? Request an MTC with your inquiry. Our GSTIN is 27ADJPA7240C1Z0, and WhatsApp inquiries reach us on +91 99202 09184.
Frequently asked questions
What is a mill test certificate?
Does Nandini Steel provide a mill test certificate with every order?
What is the difference between EN 10204 3.1 and 3.2?
What information is on a mill test certificate?
Can I get a mill test certificate for 316, 904L, Incoloy 825 or A516?
How do I verify that a mill test certificate is genuine?
Can you supply NACE MR0175 / HIC documentation for sour service?
Request a certified quote
Send us the grade, form, quantity, and the EN 10204 type along with any supplementary tests your spec calls for. We'll quote with live pricing and confirm what certification ships with the order. Everything sits ex-stock, ready for immediate dispatch, and the mill test certificate goes out when the order does. Request an MTC and quote, or just message us on WhatsApp at +91 99202 09184.