Mill test certificate format: what an EN 10204 3.1 certificate contains and how to read it
A mill test certificate (MTC; in the US a mill test report, MTR) is the document a mill sends with metal to state what was ordered and, for most types, the test results. Which type it is comes from EN 10204; what goes in it, for steel, from EN 10168.
The four types: 2.1, 2.2, 3.1 and 3.2
EN 10204:2004 has two families. Types 2.1 and 2.2 rest on non-specific inspection: the manufacturer's own procedures on products of the same specification and process, which are not necessarily the products supplied. Types 3.1 and 3.2 rest on specific inspection: before delivery, on the products supplied or on the test unit they belong to.
2.1 Declaration of compliance with the order
- Test results:
- none
- Based on:
- non-specific inspection
- Validated by:
- the manufacturer
2.2 Test report
- Test results:
- yes, from non-specific inspection
- Based on:
- non-specific inspection
- Validated by:
- the manufacturer
3.1 Inspection certificate 3.1
- Test results:
- yes, from the products supplied or their test unit
- Based on:
- specific inspection
- Validated by:
- the manufacturer's authorized inspection representative, independent of the manufacturing department
3.2 Inspection certificate 3.2
- Test results:
- yes, from the products supplied or their test unit
- Based on:
- specific inspection
- Validated by:
- that representative and either the purchaser's authorized inspection representative or the inspector designated by official regulations
Older certificates may name the 1991 edition: its 3.1.B became 3.1; 3.1.A, 3.1.C and the inspection report 3.2 became 3.2; type 2.3 was deleted. Work on a revision of EN 10204 began in 2026; the 2004 edition is the one in force.
The format, box by box (EN 10168)
EN 10204 sets the type; for steel, EN 10168 lists what a certificate may contain and gives each item a box code. Many mills print the codes beside their fields, so the same box holds the same thing on any mill's certificate, in any language.
A Commercial transaction and parties
- A01
- the manufacturer's works
- A02
- the type of document, for example EN 10204 3.1
- A03
- the certificate number
- A06
- the purchaser
- A07
- the order number
- A08
- the mill's own work number
B Description of the product
- B01
- the product
- B02
- the steel grade and its standard
- B03
- supplementary requirements
- B04
- the delivery condition
- B07
- the heat or batch number, for traceability
- B08
- the number of pieces
- B09–B11
- the dimensions
- B12
- the theoretical mass
- B13
- the actual mass
C Inspection results
- C01–C03
- where the test piece was taken, its direction and the test temperature
- C10–C29
- the tensile test: C11 yield or proof strength, C12 tensile strength, C13 elongation
- C30–C39
- hardness
- C40–C49
- the impact test
- C70
- the steelmaking process
- C71–C92
- the chemical composition
D Other tests
- D01
- marking, identification, surface, shape and dimensions
- D02–D04
- zinc coating on the top and bottom surface, roughness
- D05–D49
- non-destructive tests, for example ultrasonic testing
- D50–D99
- other product tests
Z Validation
- Z01
- the statement of compliance
- Z02
- the date of issue and validation
- Z03
- the stamp of the inspection representative
A sample 3.1 certificate
Made up for this page: no real mill, order or heat. The figures show the format only; they are not limits and say nothing about what a grade requires.
Example Steel Works
- A02 Type of inspection document
- EN 10204:2004 3.1
- Certificate number
- A03 2026-004512
- A06 Purchaser
- Example Fabrication Ltd
- A07 Order number
- PO 7781
- B02 Steel grade and standard
- EN 10025-2 S355J2+N
- B07 Heat number
- 511552
- B08 Number of pieces
- 12
- B09–B11 Dimensions
- 20 × 2500 × 12000 mm
- B13 Actual mass
- 56 520 kg
C71–C92 Chemical composition, heat analysis, %
- C
- 0.16
- Si
- 0.25
- Mn
- 1.42
- P
- 0.012
- S
- 0.004
- Cu
- 0.03
- Al
- 0.035
- CEV
- 0.41
C10–C43 Mechanical tests
- C11 ReH
- 392 MPa
- C12 Rm
- 536 MPa
- C13 A
- 27 %
- C42 KV −20 °C (single values)
- 98 / 112 / 105 J
- C43 KV −20 °C (mean)
- 105 J
Z01–Z02 We certify that the material described above has been tested and complies with the order. Date of issue 2026-09-14, stamp and signature of the inspection representative.
How to read a mill test certificate: six checks
- The type (A02) is the one your order asked for. A 2.2 gives results that need not come from your material.
- The heat number (B07) is the one stamped or painted on the material and printed on the delivery note.
- The grade, its standard and the delivery condition (B02, B04) match your order, for example EN 10025-2 S355J2+N.
- Every result (C) you need is there, in the unit of your order, and you compare it with your order's limits. Note whether the chemistry is a heat analysis or a product analysis.
- The validation (Z) has the statement, the date and the inspection representative's stamp or signature; on a 3.2 also the second inspector's.
- Material bought from a stockist comes with the mill's certificate passed on; EN 10204 has a clause on how an intermediary passes it on. If the copy is unreadable, ask for the mill's PDF.
Read a certificate into a table with Heatbook
Upload a PDF and get its heat numbers, chemistry and mechanical results as printed, each with the page it stands on and the text printed there, compared with limits you type from your order. It reads; it does not check that a certificate is genuine and never says material conforms.
Read a certificateSources
- EN 10204:2004 Metallic products: types of inspection documents (CEN; foreword, scope, definitions and types 2.1 and 2.2 read in the UNI preview)
- EN 10168:2004 Steel products: inspection documents, list of information and description
- Material Identity: EN 10168 box codes in an open format (CC BY 4.0)
- DIN: revision of EN 10204, work item begun 9 June 2026
Checked on 19 October 2026. The standards themselves are sold by the national standards bodies.