prEN ISO 18203
(Main)Steel - Determination of the thickness of surface-hardened layers (ISO/DIS 18203:2025)
Steel - Determination of the thickness of surface-hardened layers (ISO/DIS 18203:2025)
ISO 18203:2016 specifies a method of measuring the case hardening depth, surface hardening depth, nitriding hardness depth and total thickness of surface hardening depth obtained, e.g. thermal (flame and induction hardening, electron beam hardening, laser beam hardening, etc.) or thermochemical (carbonitriding, carburizing and hardening, hardening and nitriding, etc.) treatment.
Stahl - Bestimmung der Dicke gehärteter Randschichten (ISO/DIS 18203:2025)
Acier - Détermination de l'épaisseur des couches durcies superficielles (ISO/DIS 18203:2025)
ISO 18203:2016 spécifie une méthode de mesure de la profondeur de cémentation, la profondeur de durcissement de la surface, la profondeur de la dureté de nitruration et l'épaisseur totale de la profondeur de durcissement de la surface obtenue par exemple, par des traitements thermiques (durcissement par flamme et par induction, durcissement par faisceau d'électrons et par faisceau laser etc.) ou thermochimiques (carbonitruration, cémentation et durcissement, durcissement et nitruration, etc.).
Jekla - Določanje debeline površinsko utrjenih plasti (ISO/DIS 18203:2025)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-2025
Jekla - Določanje debeline površinsko utrjenih plasti (ISO/DIS 18203:2025)
Steel - Determination of the thickness of surface-hardened layers (ISO/DIS 18203:2025)
Stahl - Bestimmung der Dicke gehärteter Randschichten (ISO/DIS 18203:2025)
Acier - Détermination de l'épaisseur des couches durcies superficielles (ISO/DIS
18203:2025)
Ta slovenski standard je istoveten z: prEN ISO 18203
ICS:
77.040.99 Druge metode za Other methods of testing of
preskušanje kovin metals
77.080.20 Jekla Steels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
International
Standard
ISO/DIS 18203
ISO/TC 17/SC 7
Steel — Determination of the
Secretariat: AFNOR
thickness of surface-hardened
Voting begins on:
layers
2025-04-22
Acier — Détermination de l'épaisseur des couches durcies
Voting terminates on:
superficielles
2025-07-15
ICS: 77.040.99
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Reference number
ISO/DIS 18203:2025(en)
DRAFT
ISO/DIS 18203:2025(en)
International
Standard
ISO/DIS 18203
ISO/TC 17/SC 7
Steel — Determination of the
Secretariat: AFNOR
thickness of surface-hardened layers
Voting begins on:
Acier — Détermination de l'épaisseur des couches durcies
superficielles
Voting terminates on:
ICS: 77.040.99
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2025
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
ISO copyright office
RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: +41 22 749 01 11
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 18203:2025(en)
ii
ISO/DIS 18203:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols, abbreviations and designations . 3
5 Principle . 4
6 Apparatus . 4
7 Test specimen . 4
7.1 General .4
7.2 Measurement capability . .4
7.3 Preparation of the surface to be examined .5
8 Method of measurement . 6
8.1 Hardness testing method .6
8.1.1 CHD, SHD and NHD measurement .6
8.1.2 THD Measurement .6
8.2 Microscopic methods .7
8.2.1 Total thickness of surface hardening layers (THD) .7
9 Evaluation of the results . 8
9.1 Case hardening depth (CHD), surface hardening depth (SHD) and nitriding hardness
depth (NHD) .8
9.2 Total thickness of surface hardening depth (THD) .9
10 Test report . 9
Annex A (normative) Interpolation method for determining the CHD – SHD – NHD .11
Bibliography .13
iii
ISO/DIS 18203:2025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 7, Methods of testing
(other than mechanical tests and chemical analysis).
This second edition cancels and replaces the first edition (ISO 18203:2016), which has been technically
revised.
The main changes are as follows:
— Removal of the reference to shot peening;
— Removal of the Compound layer Thickness CLT;
— Introduction of standard test loads for the determination of hardness depths, and the procedure for
measurements in the event of arbitration;
— Extension of Table 1 by Rockwell test methods;
— Extension of Table 2 by further short characters;
— Precise definition of how the core hardness shall be tested;
— Determination of the edge distance of the first hardness impression from the edge;
— Explanation of how to determine the total thickness of surface hardening depth THD.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
ISO/DIS 18203:2025(en)
Introduction
There are several ways of creating a surface-hardened layer in steel, but the measurement of its thickness
follows the same principle, regardless of the chemical composition or heat treatment of the sample. This
document presents the basic principle of determining the thickness of surface-hardened layers as well as the
differences particular to the different methods of creating the surface-hardened layer.
No method of estimating uncertainty is presented in this document. As real applications of this procedure
accrue, the need may arise to address this topic in future revisions.
v
DRAFT International Standard ISO/DIS 18203:2025(en)
Steel — Determination of the thickness of surface-
hardened layers
1 Scope
This document specifies a method of measuring the case hardening depth, surface hardening depth, nitriding
hardness depth and total thickness of surface hardening depth obtained, e.g. thermal (flame and induction
hardening, electron beam hardening, laser beam hardening, etc.) or thermochemical (carbonitriding,
carburizing and hardening, hardening and nitriding, etc.) treatment.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 4545-1, Metallic materials — Knoop hardness test — Part 1: Test method
ISO 4545-2, Metallic materials — Knoop hardness test — Part 2: Verification and calibration of testing machines
ISO 6507-1, Metallic materials — Vickers hardness test — Part 1: Test method
ISO 6507-2, Metallic materials — Vickers hardness test — Part 2: Verification and calibration of testing machines
ISO 15787:2001, Technical product documentation — Heat-treated ferrous parts — Presentation and indications
ISO 80000-1, Quantities and units — Part 1: General
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform:
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.