ISO 20567-4:2023

Paints and varnishes — Determination of stone-chip resistance of coatings — Part 4: Mobile multi-impact testing on a small testing area

This document specifies a mobile method for evaluating the resistance of automotive finishes to chilled-iron grit projected onto the surface under test to simulate the effect of stone chipping. Results from the test specified in this document are not comparable with results specified in ISO 20567-1.

Peintures et vernis — Détermination de la résistance des revêtements aux impacts de cailloux — Partie 4: Essais de chocs multiples par projection sur une petite surface d’essai

General Information

• Status: Published
• Publication Date: 15-Mar-2023
• ICS: 87.040 - Paints and varnishes
• Technical Committee: ISO/TC 35/SC 9 - General test methods for paints and varnishes
• Drafting Committee: ISO/TC 35/SC 9 - General test methods for paints and varnishes
• Current Stage: 6060 - International Standard published
• Start Date: 16-Mar-2023
• Due Date: 15-Dec-2024
• Completion Date: 16-Mar-2023

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 20567-4
First edition
2023-03
Paints and varnishes — Determination
of stone-chip resistance of coatings —
Part 4:
Mobile multi-impact testing on a small
testing area
Reference number
ISO 20567-4:2023(E)
© ISO 2023

---------------------- Page: 1 ----------------------
ISO 20567-4:2023(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023
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: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
  © ISO 2023 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 20567-4:2023(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus and test equipment . 2
5.1 Stone-chip resistance tester . 2
5.2 Consumables . . . 5
5.2.1 Chilled-iron grit . 5
6 Apparatus functional test . 6
7 Procedure .6
8 Ev a luat ion . 7
9 Test report . 8
Annex A (normative) Pictorial reference standards for evaluating stone-chip resistance.9
Annex B (informative) Examples of suitable methods for removing loose coating .10
Bibliography .11
iii
© ISO 2023 – All rights reserved

---------------------- Page: 3 ----------------------
ISO 20567-4:2023(E)
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 35, Paints and varnishes, Subcommittee
SC 9, General test methods for paints and varnishes.
A list of all parts in the ISO 20567 series can be found on the ISO website.
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 2023 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 20567-4:2023(E)
Introduction
The stone-chip resistance of the body finish is an important quality characteristic. A standard
procedure for testing this characteristic is the method according to ISO 20567-1, which is performed
with a stationary tester on a large test area. The method described here can be used in mobile form.
v
© ISO 2023 – All rights reserved

---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 20567-4:2023(E)
Paints and varnishes — Determination of stone-chip
resistance of coatings —
Part 4:
Mobile multi-impact testing on a small testing area
1 Scope
This document specifies a mobile method for evaluating the resistance of automotive finishes to chilled-
iron grit projected onto the surface under test to simulate the effect of stone chipping.
Results from the test specified in this document are not comparable with results specified in
ISO 20567-1.
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 565, Test sieves — Metal wire cloth, perforated metal plate and electroformed sheet — Nominal sizes
of openings
ISO 2808, Paints and varnishes — Determination of film thickness
ISO 4618, Paints and varnishes — Vocabulary
ISO 11124-2, Preparation of steel substrates before application of paints and related products —
Specifications for metallic blast-cleaning abrasives — Part 2: Chilled-iron grit
ISO 11125-2, Preparation of steel substrates before application of paints and related products — Test
methods for metallic blast-cleaning abrasives — Part 2: Determination of particle size distribution
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4618 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Principle
The stone-chip resistance of the coating is tested with many small, sharp-edged impact bodies, which
impact in portions and are largely independent of one another. The material used in the test is chilled-
iron grit, which is projected onto the coating at an angle of 90° using compressed air. The extent of the
damage depends on the working pressure, the grit, the projection duration and the design of the tester.
Loose fragments of coating material are removed. The degree of damage is evaluated by comparison
with pictorial reference standards.
1
© ISO 2023 – All rights reserved

---------------------- Page: 6 ----------------------
ISO 20567-4:2023(E)
5 Apparatus and test equipment
Ordinary laboratory apparatus, together with the following shall be used.
5.1 Stone-chip resistance tester
5.1.1 Tester including pressure regulator, hoses, connections and connection adapters (see Figures 1
and 2).
The dosing device shall be designed such that chilled-iron grit for the test (see 7.2) can be delivered in
(10 ± 1) s.
The compressed air supply for the tester (compressed air line system or compressor) shall have an oil
separator and water separator and shall meet the following requirements:
— output pressure min. 400 kPa;
— inner diameter of the connection hose min. 9,52 mm (3/8 inch);
— the connection hose between the compressed air supply and the tester shall be dimensioned (inside
diameter, length) such that the correct working pressure can be set (see 6.1).
2
  © ISO 2023 – All rights reserved

---------------------- Page: 7 ----------------------
ISO 20567-4:2023(E)
Key
1 sample
2 projection window
3 a
...

2022-09-27 Style Definition: Heading 1: Indent: Left: 0 pt, First
line: 0 pt, Tab stops: Not at 21.6 pt
ISO/FDIS 20567--4:2022(E)
Style Definition: Heading 2: Font: Bold, Tab stops: Not
at 18 pt
ISO TC 35/SC 9/WG 31
Style Definition: Heading 3: Font: Bold
Style Definition: Heading 4: Font: Bold
Date: 2022-11-25
Style Definition: Heading 5: Font: Bold
Secretariat: BSI
Style Definition: Heading 6: Font: Bold
Style Definition: ANNEX
Paints and varnishes — Determination of stone-chip resistance of coatings — Part 4:
Mobile multi-impact testing on a small testing area
Style Definition: Footer
Style Definition: Header
Style Definition: AMEND Terms Heading: Font: Bold
Style Definition: AMEND Heading 1 Unnumbered:
Font: Bold
Style Definition: Hashtag1
Style Definition: List Bullet 2: Indent: Left: 14.15 pt,
Hanging: 18 pt, No bullets or numbering, Tab stops:
32.15 pt, List tab
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46.3 pt, List tab
Style Definition: List Bullet 4: Indent: Left: 42.45 pt,
Hanging: 18 pt, No bullets or numbering, Tab stops:
60.45 pt, List tab
Style Definition: List Bullet 5: Indent: Left: 56.6 pt,
Hanging: 18 pt, No bullets or numbering, Tab stops:
74.6 pt, List tab
Style Definition: List Number 5: Indent: Left: 56.6 pt,
Hanging: 18 pt, No bullets or numbering, Tab stops:
74.6 pt, List tab
Style Definition: Mention1
Style Definition: Smart Hyperlink1
Style Definition: Unresolved Mention1
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Formatted: English (United Kingdom)
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---------------------- Page: 1 ----------------------
ISO/DIS FDIS 20567-4:2022(E)
© ISO 2022 Formatted
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: [phone]
Email: [e-mail]
Website: www.iso.orgwww.iso.org
Formatted: English (United Kingdom)
Formatted: English (United Kingdom)
Published in Switzerland
Formatted: Font: 11 pt
Formatted: Space After: 0 pt, Line spacing: single
2 © ISO 2022 – All rights reserved
ii © ISO 2022 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/DIS FDIS 20567-4:2022(E)
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus and test equipment . 2
5.1 Stone-chip resistance tester . 2
5.2 Consumables . 5
6 Apparatus functional test . 6
7 Procedure . 6
8 Evaluation . 7
9 Test report . 8
Annex A (normative) Pictorial reference standards for evaluating stone-chip resistance . 9
Annex B (informative) Examples of suitable methods for removing loose coating . 10
B.1 Brushing . 10
B.2 Using adhesive tape . 10
B.3 Using compressed air or nitrogen . 10
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus and test equipment . 2
5.1 Stone-chip resistance tester . 2
5.2 Consumables . 5
6 Apparatus functional test . 6
7 Procedure . 6
8 Evaluation . 7
9 Test report . 8
Annex A (normative) Pictorial reference standards for evaluating stone-chip resistance . 9
Annex B (informative) Examples of suitable methods for removing loose coating . 10
Formatted: Font: 11 pt
B.1 Brushing . 10
Formatted: Space After: 0 pt, Line spacing: single
© ISO 2022 – All rights reserved 3
© ISO 2022 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO/DIS FDIS 20567-4:2022(E)
B.2 Using adhesive tape . 10
B.3 Using compressed air or nitrogen . 10
Formatted: Font: 11 pt
Formatted: Space After: 0 pt, Line spacing: single
4 © ISO 2022 – All rights reserved
iv © ISO 2022 – All rights reserved

---------------------- Page: 4 ----------------------
ISO/DIS FDIS 20567-4:2022(E)
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/directiveswww.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/patentswww.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.htmlwww.iso.org/iso/foreword.html.
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.
This document was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee
SC 9, General test methods for paints and varnishes.
A list of all parts in the ISO 20567 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
Formatted: English (United Kingdom)
complete listing of these bodies can be found at
Formatted: Don't adjust space between Latin and
www.iso.org/members.htmlwww.iso.org/members.html.
Asian text, Don't adjust space between Asian text and
numbers

Formatted: English (United Kingdom)
Formatted: Font: 11 pt
Formatted: Space After: 0 pt, Line spacing: single
© ISO 2022 – All rights reserved 5
© ISO 2022 – All rights reserved v

---------------------- Page: 5 ----------------------
ISO/DIS FDIS 20567-4:2022(E)
Introduction
The stone-chip resistance of the body finish is an important quality characteristic. A standard procedure
for testing this characteristic is the method according to ISO 20567--1, which is performed with a
stationary tester on a large test area. The method described here can be used in mobile form.
Formatted: Font: 11 pt
Formatted: Space After: 0 pt, Line spacing: single
6 © ISO 2022 – All rights reserved
vi © ISO 2022 – All rights reserved

---------------------- Page: 6 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 20567-4:2022(E)

Formatted: Different first page header
Paints and varnishes — Determination of stone-chip resistance of
coatings — Part 4: Mobile multi-impact testing on a small testing
area
1 Scope
This document specifies a mobile method for evaluating the resistance of automotive finishes to chilled-
iron grit projected onto the surface under test to simulate the effect of stone chipping.
Results from the test specified in this document are not comparable with results specified in accordance
with ISO 20567--1.
2 Normative references
Formatted: Tab stops: Not at 21.6 pt
The following documents are referred to in the text in such a way that some or all of their content
Formatted: Adjust space between Latin and Asian text,
constitutes requirements of this document. For dated references, only the edition cited applies. For
Adjust space between Asian text and numbers
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 565, Test sieves — Metal wire cloth, perforated metal plate and electroformed sheet — Nominal sizes of
openings
ISO 2808, Paints and varnishes — Determination of film thickness
ISO 4618, Paints and varnishes — Terms and definitions
ISO 11124--2, Preparation of steel substrates before application of paints and related products —
Specifications for metallic blast-cleaning abrasives — Part 2: Chilled-iron grit
ISO 11125--2, Preparation of steel substrates before application of paints and related products — Test
methods for metallic blast-cleaning abrasives — Part 2: Determination of particle size distribution
3 Terms and definitions
Formatted: Tab stops: Not at 21.6 pt
For the purposes of this document, the terms and definitions given in ISO 4618 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obphttps://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/https://www.electropedia.org/
4 Principle
Formatted: Tab stops: Not at 21.6 pt
The stone-chip resistance of the coating is tested with many small, sharp-edged impact bodies, which
impact in portions and are largely independent of one another. The material used in the test is chilled-
iron grit, which is projected onto the coating at an angle of 90° using compressed air. The extent of the
© ISO 2022 – All rights reserved 1

---------------------- Page: 7 ----------------------
ISO/FDIS 20567-4:2022(E)
damage depends on the working pressure, the grit, the projection duration and the design of the tester.
Loose fragments of coating material are removed. The degree of damage is evaluated by comparison with
pictorial reference standards.
5 Apparatus and test equipment
Formatted: Tab stops: Not at 21.6 pt
Ordinary laboratory apparatus, together with the following shall be used.
5.1 Stone-chip resistance tester
Formatted: Tab stops: Not at 21.6 pt + 29.75 pt
5.1.1 Tester including pressure regulator, hoses, connections and connection adapters (see Figures 1
Formatted: Font: Bold

and 2).
Formatted: cite_fig
Formatted: Default Paragraph Font
The dosing device shall be designed such that chilled-iron grit for the test (see 7.2) can be delivered in
(10 ± 1) s.
The compressed air supply for the tester (compressed air line system or compressor) shall have an oil
separator and water separator and shall meet the following requirements:
 — output pressure min. 400 kPa;
Formatted: List Continue 1, Line spacing: single, No
bullets or numbering, Tab stops: 19.85 pt, Left + 39.7
 — inner diameter of the connection hose min. 9,52 mm (3/8 inch); pt, Left + 59.55 pt, Left + 79.4 pt, Left + 99.25 pt, Left
+ 119.05 pt, Left + 138.9 pt, Left + 158.75 pt, Left +
178.6 pt, Left + 198.45 pt, Left
 — the connection hose between the compressed air supply and the tester shall be dimensioned
(inside diameter, length) such that the correct working pressure can be set (see 6.1).

Formatted: Font: 11 pt
Formatted: Space After: 0 pt, Line spacing: single
2 © ISO 2022 – All rights reserved
2 © ISO 2022 – All rights reserved

---------------------- Page: 8 ----------------------
ISO/FDIS 20567-4:2022(E)
Formatted: Right

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Key
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1 sample
Formatted: Don't keep with next
2 projection wind
...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 20567-4
ISO/TC 35/SC 9
Paints and varnishes — Determination
Secretariat: BSI
of stone-chip resistance of coatings —
Voting begins on:
2022-12-12
Part 4:
Voting terminates on:
Mobile multi-impact testing on a small
2023-02-06
testing area
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 SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 20567-4:2022(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. © ISO 2022

---------------------- Page: 1 ----------------------
ISO/FDIS 20567-4:2022(E)
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 20567-4
ISO/TC 35/SC 9
Paints and varnishes — Determination
Secretariat: BSI
of stone-chip resistance of coatings —
Voting begins on:
Part 4:
Voting terminates on:
Mobile multi-impact testing on a small
testing area
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
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.
RECIPIENTS OF THIS DRAFT ARE INVITED TO
ISO copyright office
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
CP 401 • Ch. de Blandonnet 8
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
CH-1214 Vernier, Geneva
DOCUMENTATION.
Phone: [phone]
IN ADDITION TO THEIR EVALUATION AS
Reference number
Email: [e-mail]
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 20567-4:2022(E)
Website: www.iso.org
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
Published in Switzerland
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
ii
  © ISO 2022 – All rights reserved
NATIONAL REGULATIONS. © ISO 2022

---------------------- Page: 2 ----------------------
ISO/FDIS 20567-4:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus and test equipment . 2
5.1 Stone-chip resistance tester . 2
5.2 Consumables . . . 5
5.2.1 Chilled-iron grit . 5
6 Apparatus functional test . 6
7 Procedure .6
8 Ev a luat ion . 7
9 Test report . 8
Annex A (normative) Pictorial reference standards for evaluating stone-chip resistance.9
Annex B (informative) Examples of suitable methods for removing loose coating .10
Bibliography .11
iii
© ISO 2022 – All rights reserved

---------------------- Page: 3 ----------------------
ISO/FDIS 20567-4:2022(E)
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 35, Paints and varnishes, Subcommittee
SC 9, General test methods for paints and varnishes.
A list of all parts in the ISO 20567 series can be found on the ISO website.
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 2022 – All rights reserved

---------------------- Page: 4 ----------------------
ISO/FDIS 20567-4:2022(E)
Introduction
The stone-chip resistance of the body finish is an important quality characteristic. A standard
procedure for testing this characteristic is the method according to ISO 20567-1, which is performed
with a stationary tester on a large test area. The method described here can be used in mobile form.
v
© ISO 2022 – All rights reserved

---------------------- Page: 5 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 20567-4:2022(E)
Paints and varnishes — Determination of stone-chip
resistance of coatings —
Part 4:
Mobile multi-impact testing on a small testing area
1 Scope
This document specifies a mobile method for evaluating the resistance of automotive finishes to chilled-
iron grit projected onto the surface under test to simulate the effect of stone chipping.
Results from the test specified in this document are not comparable with results specified in
ISO 20567-1.
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 565, Test sieves — Metal wire cloth, perforated metal plate and electroformed sheet — Nominal sizes
of openings
ISO 2808, Paints and varnishes — Determination of film thickness
ISO 4618, Paints and varnishes — Terms and definitions
ISO 11124-2, Preparation of steel substrates before application of paints and related products —
Specifications for metallic blast-cleaning abrasives — Part 2: Chilled-iron grit
ISO 11125-2, Preparation of steel substrates before application of paints and related products — Test
methods for metallic blast-cleaning abrasives — Part 2: Determination of particle size distribution
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4618 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Principle
The stone-chip resistance of the coating is tested with many small, sharp-edged impact bodies, which
impact in portions and are largely independent of one another. The material used in the test is chilled-
iron grit, which is projected onto the coating at an angle of 90° using compressed air. The extent of the
damage depends on the working pressure, the grit, the projection duration and the design of the tester.
Loose fragments of coating material are removed. The degree of damage is evaluated by comparison
with pictorial reference standards.
1
© ISO 2022 – All rights reserved

---------------------- Page: 6 ----------------------
ISO/FDIS 20567-4:2022(E)
5 Apparatus and test equipment
Ordinary laboratory apparatus, together with the following shall be used.
5.1 Stone-chip resistance tester
5.1.1 Tester including pressure regulat
...