# EN 10168 Mill certificates

# Introduction

The European Standard EN 10168 (opens new window) defines five information groups to document the results of steel product inspection. For each information group 99 or 100 fields are defined with a very basic naming convention - letter for the section and 2 digit number.

Information Group Fields
Commercial transactions and parties involved A01 to A99
Description of products B01 to B99
Inspection C00 to C99
Other tests D01 to D99
Validation Z01 to Z99

In each group some fields are designated for specific information and in all groups are many fields for designation and many for free usage. It should be noted that the standard does not give any recommendations on formats so basically all fields have to be considered as strings from a software development perspective.

# Examples

To illustrate the designation of sections (or fields in our understanding) some examples are given.

No Section designation Contents
A01 Manufacturer's works Name and address of the works where the products were manufactured.
B07 Identification of the product Indications for the traceability of the products, e.g. cast number, ingot number, rolling number, batch number, test number.
C11 Yield or proof strength Yield or proof strength recorded in MPa.
C93 - C99 Supplementary information Available for supplementary information on the chemical composition.

# Current situation

We have been studying certificates created by many market participants viewing them from the view point of machines - how is data provided for easy and high quality processing. In the following paragraphs we analyze some of the common problems.

# Description of products

To describe a product there are basically four essential fields:

No Section designation Contents
B01 Product Description of the product form (e.g. : heavy plate, section, wide flat, tube, hollow section, etc.) and, where appropriate, surface condition, with reference to the dimensional standard, if applicable.
B02 Steel Designation ISteel name or number and additional symbols and the product specification for the steel.
B03 Any supplementary requirements This section is for indicating special requirements, agreed at the time of ordering, not appearing in sections B 01 and B 02.
B04 Product delivery condition Delivery condition of the products as specified in the applicable product specification.

The real world is basically a mess illustrated by an overview of approaches we have seen:

  • Product EW Steel Pipes S355J2H EN 2019/1/2-2006 written to a combined section for B01 and B02
  • Product in B02 split into
    • Product Norm
    • Material Norm
    • Mass Norm
    • Steel Grade
    • Product Code
  • Product TUBE NORMALIZED (+N), EN 10210-1 ATA in B01, steel grade S355J2H/NH in B02 plus a combined section of B04 and B09-B11 with SGM 100x100x12,5x12000 S355J2H 10210 HF
  • No section specified with S355J2H N / E355+N / St 52.0 N and DIN 2448: 81 EN 10210-1; 2: 06/ EN 10297-1: 03; DIN 1629: 84 which points to the interesting case a product complies to multiple standards.
  • One company put everything into a section described B01-B04
  • Steel grade C45+A/1.1730 in B02, the norm EN 10083-2:2006 is provided in section B14 as supplementary information.
  • One company splits B02 into B02.1 for steel grade and B02.2 for the norm.

# Identification of the product

To identify a product section B07 is designated by the norm, which describes it with

Indications for the traceability of the products, e.g. cast number, ingot number, rolling number, batch number, test number.

In our simple understanding the section should contain the batch number of the product with which the mill certificate comes, e.g. the production batch number for some tubes. However, tracability must be ensured back to the inital cast number so in practice people developed some workarounds:

  • Split of B07 into B07.1, into which goes Heat Number and B07.2, into which goes Specimen number.
  • Many occurances of B07, put into context with processing step and its inspection, e.g. a batch number associated with the chemical analysis and a batch number associated with the product. We have seen up to five B07 on one mill certificate.

This is perfectly fine when looking at it from the production process and on paper. However, dealing with more than one B07 in an format to be consumed by software is getting tricky pretty fast.

# Chemical Analysis

Sections C71 to C99 are dedicated to the chemical analysis but leaving open which chemical element goes into which section.

# Conclusion

Based on our observations we came to the following conclusions on EN 10168:

  • It is a very open standard enabling users to add any kind of information which is produced in inspecting steel products.
  • It defines a somehow precise definition for a very limited set of information.
  • The industry established some common practices to provide certain information.
  • The target platform for the standard is paper which is fine as paper (and nowadays PDF) are the only means to establish document character.
  • There is a need for data in a machine readable format, confirmed by basic tools offered by some companies.

# Objectives for a new format

Based on our observations and conclusions we set ourselves the following objectives for the design of an electronic format:

  • The target platform for the format are both machines and humans (in the forma of PDFs).
  • The format must be developer friendly enabling easy implementation of both the creation of data in the format and reading it for further processing.
  • The format should provide standards and guidelines for many data points.
  • The format should flexible to integrate all kinds of information.
  • The format should make it easy to render great looking PDF documents following established practices.

The data format in the next chapters tries to perform the balancing act to meet this to some extend contradictory objectives.

# Components

To simplify design and maintance components to be used multiple times in the schema defining the structure of the JSON format are defined.

# Chemical Element

EN 10168 defines that in fields C71 to C92 the share of chemical elements has to be provided, but it does not map chemical elements to fields. The solution is to require both the Symbol and Actual value.

Attribute Description Mandatory Visible
Symbol The symbol of the element Yes Yes
Actual The measured part of the element in percentage. Yes Yes
Minimum The minimum if defined by the product specification, otherwise the element must not provided. No Yes
Maximum The maximum as defined by the product specification, otherwise the element must not provided. No Yes

# Company

Attribute Description Mandatory Visible
Name The name of the company Yes Yes
Street The address, a string or an array of up to three strings line Yes Yes
ZipCode The ZIP code Yes Yes
City The city Yes Yes
Country The two-letter ISO country code according to ISO 3166 (opens new window). Yes Yes
Email The email address to be used to send certificates to the company. No Yes
Identifier One or more unique company identifiers. Currently, VAT (opens new window), DUNS (opens new window), and Cage Codes (opens new window) are supported. One of VAT or DUNS is required. Yes No
AdditionalInformation An array of additional free text information on the company. No Yes

# Key Value Object

EN 10168 implements flexibility by defining plenty of supplementary information fields to add any kind of information. To structure the information for easier processing and rendering a key value object is used. For proper rendering it is extened with additional parameters.

Attribute Description Mandatory Visible
Key A key Yes Yes
Value A value, type string Yes Yes
Unit Unit of value No Yes
Interpretation An interpretation of the value, e.g. "compliant" to a requirement given in the key No Yes
Type The data type of the value, so that numbers can be rendered according language conventions. No No

# Measurement

Attribute Description Mandatory Visible
Property Property measured Yes Yes
Value Measured or calculated Value (e.g. mean of individual measurements). Yes Yes
Unit Unit of value No Yes
Minimum Minimum if defined by the product specification, otherwise the element must not provided. No Yes
Maximum Maximum as defined by the product specification, otherwise the element must not provided. No Yes

# Product Description

The field B02 contains all product releated information which can be a lot. To improve readability and simplify processing a structure is introduced as described bewlo.

Attribute Description Mandatory Visible
ProductNorm Array of product norm designations. Yes Yes
MaterialNorm Array of material norms. Yes Yes
MassNorm Array of mass norms. No Yes
SteelDesignation Array of steel designations. No Yes

# Product Shape

The field B09 contains the information on the product form and dimensions. To improve readability and simplify processing a structures for products and its dimensions are defined.

Shape Dimensions
Tube OuterDiameter, WallThickness
Rectangular Tube Width, Height, WallThinkness
QuadraticT ube SideLength, WallThickness
Pipe SideLength, WallThickness
Rectangular Pipe Width, Height, WallThinkness
Coil Width, WallThinkness
Round Bar Diameter
Hexagonal Bar Diameter
Flat Bar Width, WallThinkness
Sheet Width, WallThinkness
Slab Width, WallThinkness
Plate Width, WallThinkness
Scroll Width, WallThinkness
Strip Width, WallThinkness
Other Free text describing the form

Remark: the length of a product has to be provided in B10.

# Schema

The JSON schema is structured as illustrated in the diagram.

In the following chapters the defined components are applied to each information group forming a well defined data structure still matching the definitions of EN 10168.

# Commercial transaction

Field Description Mandatory Visible
A01 The manufacturer's works which delivers the certificate Yes Yes
A02 The type of inspection document, e.g. 'EN 10204 3.1 Certificate' Yes Yes
A03 The document number of the certifcate Yes Yes
A04 The mark of the manufacturer as base64 png file. Yes Yes
A05 The originator of the document, not necessarily equal to A01 Yes Yes
A06 The purchaser of the product and receiver of the certificate No Yes
A06.1 The purchaser of the product if A06 is not provided. No Yes
A06.2 The consignee of the product only if A06.1 is provided. No Yes
A06.3 The consignee of the certificate only if A06.1 is provided No Yes
A07 Purchase number Yes Yes
A08 Manufacturer's work number No Yes
A09 The article number used by the purchaser No Yes
A10 - A96 Supplementary information No Yes
A97 A designated field for the position number in the order No Yes
A98 A designated field for the delivery note number No Yes
A99 A designated field for the aviso document number No Yes

# Product

Field Description Mandatory Visible
B01 The product Yes Yes
B02 Product properties Yes Yes
B03 Any supplementary requirements No Yes
B04 The delivery conditions for the product No Yes
B05 Reference heat treatment of samples No Yes
B06 Marking of the product Yes Yes
B07 Identification of the product, usually batch, charge or lot number No Yes
B08 Number of pieces of the product. No Yes
B09 Objects describing different forms Yes Yes
B10 Product dimensions - length of the product No Yes
B11 Product dimensions No Yes
B12 Theoretical mass No Yes
B13 Acutal mass No Yes
B14 - B98 Product description Supplementary information No Yes
B99 A designated field for the CO₂ equivalent No Yes

# Analysis

Field Description Mandatory Visible
C00 Heat or melt number defining the chemical properties Yes Yes
C01 Location of the sample No Yes
C02 Direction of the test pieces No Yes
C03 Test temperature No Yes
C04 - C09 Supplementary information No Yes
C10 Tensile test - shape of the test piece No Yes
C11 Tensile test - yield or proof strength No Yes
C12 Tensile test - tensile strength No Yes
C13 Tensile test - elongation after fracture No Yes
C14 A designated field for vertical anisotropy (r-value) No Yes
C15 A designated field for vertical anisotropy (r-value) No Yes
C16 - C29 Tensile test supplementary information No Yes
C30 Hardness test - method No Yes
C31 Hardness test - array of individual values No Yes
C32 Hardness test - the average value of the individual values measured No Yes
C33 - C39 Hardness test supplementary information No Yes
C40 Notched bar impact test - type of test piece No Yes
C41 Notched bar impact test - width of test piece No Yes
C42 Notched bar impact test - array of individual values No Yes
C43 Notched bar impact test - mean value No Yes
C44 - C49 Notched bar impact test supplementary information No Yes
C50 - C69 Other mechanical tests No Yes
C70 The metallurgic process: Y = Basic oxygen process, E = Electric furnace No Yes
C71 - C109 Share of chemical element No Yes
C110 - C120 Chemical analysis supplementary information No Yes


  • EN 10168 assigns fields C71 to C92 to the chemical analysis. Many certificates contain the share of many more elements so the list of fields was extended to C109.

# Other Tests

Field Description Mandatory Visible
D01 Marking and identification, surface appearance, shape and dimensional properties No Yes
D02 A designated field for zinc coating on the top surface No Yes
D03 A designated field for zinc coating on the bottom surface No Yes
D04 A designated field for roughness No Yes
D05 - D49 Non-desctructive tests No Yes
D50 - D99 Other product tests No Yes

# Validation

Field Description Mandatory Visible
Z01 Statement of compliance Yes Yes
Z02 Date of issue and validation Yes Yes
Z03 Stamp of the inspection representative No Yes
Z04 CE marking with properties CE image, the identification number of the notified body, year of issueing and document number No Yes
Z05 - Z99 Supplementary Information No Yes

# Features

Additional features complement the JSON Schema increasing its utility for the industry.

# Standardization of layout

# Current practice

Currently, all market participants provide certificates in an individual layout driven by the following parameters:

  • The data available in their ERP and QM systems which varies a lot.
  • The corporate identity and design guidelines.
  • The technologies and their capabilities to define layouts and renderings of PDF documents.

In addition, all vendors might use slightly different wording for the same fields on certificates. This leads to a situation in which the variety of layouts and wordings results in difficulties and errors in processing inbound certificates. Furthermore, all attempts to use OCR to automate processing fail because of the variance of designs - even with a lot of effort to automate recognition and mapping, humans are required to review the results as the error rates are simply unacceptable.

# Objectives

The objectives for a new layout are

  • Standardized and well-defined document structure.
  • Easy to read for humans.

It should be mentioned that a standardized layout of PDF and HTML renderings is well appreciated by receivers of certificates.

# Sample rendering


# Layout rules

The layout of PDF and HTML renderings are divided into the sections as illustrated.

Certificate layout

Section Rule
Logo The logo must be provided as Base64 (opens new window) encoded PNG file (opens new window). It will be rendered 150 pixel wide.
Information group a - parties The parties A01, A06 or A06.1, A06.2 and A06.3
Information group a The commercial transaction data
Information group b
Information group c and d The inspection results which can be multiple ones, for each processing step and test with a specfic identifier for a probe.
Information group z The validation information including an optional CE marking.

# Rendering in one or two languages

# Observations

In many cases, customers want to get certificates in multiple languages. In one example below English and French are configured: French could be addressing the headquarters and English to help shop floor operators without knowledge to read and understand the contents of certificates. Furthermore, most current implementations of certificate renderings do not or only partially comply with the conventions to localize number and date formats of the target language, possibly leading to misinterpretations.

The objectives for an implementation are the

  • Standardization of translations for the terms used on PDF renderings for a large set of languages.
  • Automation of localization of number and date formats.
  • Enabling the addition of new languages simply.

# Example English certificate

In the example (opens new window) the language EN was specified for rendering.

# Cutout from JSON
  "Certificate": {
    "CertificateLanguages": [
# Cutout from PDF


# Example English and French certificate

In the example (opens new window) the languages EN and FR were specified for rendering.

# Cutout from JSON
  "Certificate": {
    "CertificateLanguages": [
# Cutout from PDF

Polish and Italian

# Additional languages

Additional languages can be easily added by the following steps:

  • Add the ISO code for the new language to CertificateLanguages (opens new window).
  • Add translations for all field names in <ISO Code>.json to the repository root.
  • Add new fixtures in test/fixtures and then to test/validate.spec.js and test/render.spec.js.
  • Release a new version of the schema.

# Fixing errors

Translation errors can be reported by submitting a bug report on Github (opens new window).

# Tools

Tools supporting the validation, testing, and rendering as PDF and HTML are available at https://www.npmjs.com/org/s1seven (opens new window). These tools implement the features described in the following for easy adoption by users and developers. The source code and documentation can be found at https://github.com/s1seven/schema-tools (opens new window).

# Licensing

The format definition, examples, translation, and the documentation on this site are published under GNU Affero General Public License (opens new window).