ISO 185:2020

INTERNATIONAL ISO
STANDARD 185
Fourth edition
2020-05
Grey cast irons — Classification
Fontes à graphite lamellaire — Classification
Reference number
©
ISO 2020
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Designation . 2
5 Order information . 2
6 Manufacture . 2
7 Requirements . 3
7.1 Mechanical properties . 3
7.2 Tensile properties . 3
7.2.1 General. 3
7.2.2 Test pieces machined from cast samples . 3
7.2.3 Test pieces cut from a casting . 3
7.3 Hardness properties . 6
7.4 Graphite structure . 7
8 Sampling . 7
8.1 General . 7
8.2 Types of samples . 7
8.3 Samples for tensile test . 8
8.3.1 Size of cast samples . 8
8.3.2 Frequency and number of test samples . 8
8.3.3 Separately cast samples . 8
8.3.4 Side-by-side cast samples . 8
8.3.5 Cast-on samples . 9
8.3.6 Samples cut from a casting.11
8.4 Samples for hardness test .12
9 Test methods .12
9.1 Tensile test .12
9.2 Brinell hardness test .14
9.3 Graphite structure .14
9.4 Alternative test procedures.14
10 Retests .14
10.1 Need for retests .14
10.2 Test validity .14
10.3 Nonconforming test results .15
10.4 Heat treatment of samples and castings .15
Annex A (informative) Information on mechanical and physical properties in addition to
that given in Tables 1 and 2 .16
Annex B (informative) Additional information on the relationship between hardness and
tensile strength of grey cast irons .18
Annex C (informative) Additional information on the relationship between tensile strength,
hardness and wall thickness of grey iron castings .21
Annex D (informative) Cross-references of ISO 185 grade designations to other standard
grades of grey cast irons .25
Bibliography .27
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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
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 25, Cast irons and pig irons.
This fourth edition cancels and replaces the third edition (ISO 185:2019), of which it constitutes a minor
revision. The changes to the previous edition are as follows:
— Correction to typographical error for relevant wall thickness of ISO 185/JL/HBW235 in Table 2;
corrected from “4” to “40”. As a result of this change, the year of publication of ISO 185 in Annex D,
Table D.1, column 1, updated from 2019 to 2020 to conform with this new edition.
— Symbols for Brinell hardness and relative hardness updated to H and H , respectively, in B.2 and
B R
Figure B.1.
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 2020 – All rights reserved

Introduction
This document deals with the classification of grey cast irons, subdivided into two groups:
— materials specified by their tensile strength;
— materials specified by their hardness.
It is also possible to specify grey cast irons by a combination of tensile strength and hardness.
NOTE This document does not cover technical delivery conditions for grey iron castings.
The properties of grey cast iron depend on the form and distribution of the graphite and on the
structure of the matrix.
For many applications, tensile strength and hardness are not the only properties of interest to casting
designers. Other mechanical or physical properties can be decisive for the use of grey iron. For example:
— the thermal capacity and the thermal diffusivity for disc brakes;
— the damping capacity for engine blocks or machine beds;
— the thermocycle fatigue for exhaust manifolds or ingot moulds.
Therefore, Annex A provides additional information of interest to casting designers.
Furthermore:
— Annex B contains additional information on the relationship between hardness and tensile strength;
— Annex C contains additional information on the relationship between tensile strength, hardness
and wall thickness of grey iron castings;
— Annex D provides cross-references of ISO 185 grade designations to other standard grades of grey
cast irons.
INTERNATIONAL STANDARD ISO 185:2020(E)
Grey cast irons — Classification
1 Scope
This document specifies the properties of unalloyed and low-alloyed grey cast irons used for castings
that have been manufactured in sand moulds or in moulds with comparable thermal behaviour.
This document specifies the characterizing properties of grey cast irons by any of the following:
a) the tensile strength of cast samples;
b) if agreed by the manufacturer and the purchaser, the tensile strength of samples cut from a casting;
c) if agreed between the manufacturer and the purchaser, the hardness of the material determined on
castings or on a cast-on knob.
If agreed by the manufacturer and the purchaser, the combination of tensile strength from option a) or
option b) and plus hardness from option c) can be specified. Inf
...

INTERNATIONAL ISO
STANDARD 185
Fourth edition
2020-05
Grey cast irons — Classification
Fontes à graphite lamellaire — Classification
Reference number
©
ISO 2020
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Designation . 2
5 Order information . 2
6 Manufacture . 2
7 Requirements . 3
7.1 Mechanical properties . 3
7.2 Tensile properties . 3
7.2.1 General. 3
7.2.2 Test pieces machined from cast samples . 3
7.2.3 Test pieces cut from a casting . 3
7.3 Hardness properties . 6
7.4 Graphite structure . 7
8 Sampling . 7
8.1 General . 7
8.2 Types of samples . 7
8.3 Samples for tensile test . 8
8.3.1 Size of cast samples . 8
8.3.2 Frequency and number of test samples . 8
8.3.3 Separately cast samples . 8
8.3.4 Side-by-side cast samples . 8
8.3.5 Cast-on samples . 9
8.3.6 Samples cut from a casting.11
8.4 Samples for hardness test .12
9 Test methods .12
9.1 Tensile test .12
9.2 Brinell hardness test .14
9.3 Graphite structure .14
9.4 Alternative test procedures.14
10 Retests .14
10.1 Need for retests .14
10.2 Test validity .14
10.3 Nonconforming test results .15
10.4 Heat treatment of samples and castings .15
Annex A (informative) Information on mechanical and physical properties in addition to
that given in Tables 1 and 2 .16
Annex B (informative) Additional information on the relationship between hardness and
tensile strength of grey cast irons .18
Annex C (informative) Additional information on the relationship between tensile strength,
hardness and wall thickness of grey iron castings .21
Annex D (informative) Cross-references of ISO 185 grade designations to other standard
grades of grey cast irons .25
Bibliography .27
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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
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 25, Cast irons and pig irons.
This fourth edition cancels and replaces the third edition (ISO 185:2019), of which it constitutes a minor
revision. The changes to the previous edition are as follows:
— Correction to typographical error for relevant wall thickness of ISO 185/JL/HBW235 in Table 2;
corrected from “4” to “40”. As a result of this change, the year of publication of ISO 185 in Annex D,
Table D.1, column 1, updated from 2019 to 2020 to conform with this new edition.
— Symbols for Brinell hardness and relative hardness updated to H and H , respectively, in B.2 and
B R
Figure B.1.
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 2020 – All rights reserved

Introduction
This document deals with the classification of grey cast irons, subdivided into two groups:
— materials specified by their tensile strength;
— materials specified by their hardness.
It is also possible to specify grey cast irons by a combination of tensile strength and hardness.
NOTE This document does not cover technical delivery conditions for grey iron castings.
The properties of grey cast iron depend on the form and distribution of the graphite and on the
structure of the matrix.
For many applications, tensile strength and hardness are not the only properties of interest to casting
designers. Other mechanical or physical properties can be decisive for the use of grey iron. For example:
— the thermal capacity and the thermal diffusivity for disc brakes;
— the damping capacity for engine blocks or machine beds;
— the thermocycle fatigue for exhaust manifolds or ingot moulds.
Therefore, Annex A provides additional information of interest to casting designers.
Furthermore:
— Annex B contains additional information on the relationship between hardness and tensile strength;
— Annex C contains additional information on the relationship between tensile strength, hardness
and wall thickness of grey iron castings;
— Annex D provides cross-references of ISO 185 grade designations to other standard grades of grey
cast irons.
INTERNATIONAL STANDARD ISO 185:2020(E)
Grey cast irons — Classification
1 Scope
This document specifies the properties of unalloyed and low-alloyed grey cast irons used for castings
that have been manufactured in sand moulds or in moulds with comparable thermal behaviour.
This document specifies the characterizing properties of grey cast irons by any of the following:
a) the tensile strength of cast samples;
b) if agreed by the manufacturer and the purchaser, the tensile strength of samples cut from a casting;
c) if agreed between the manufacturer and the purchaser, the hardness of the material determined on
castings or on a cast-on knob.
If agreed by the manufacturer and the purchaser, the combination of tensile strength from option a) or
option b) and plus hardness from option c) can be specified. Inf
...