ISO 179-1

Plastics — Determination of Charpy impact properties — Part 1: Non-instrumented impact test

This document specifies a method for determining the Charpy impact strength of plastics under defined conditions. A number of different types of specimen and test configurations are defined. Different test parameters are specified according to the type of material, the type of test specimen and the type of notch. The method can be used to investigate the behaviour of specified types of specimen under the impact conditions defined and for estimating the brittleness or toughness of specimens within the limitations inherent in the test conditions. It can also be used for the determination of comparative data from similar types of material.

Plastiques — Détermination des caractéristiques au choc Charpy — Partie 1: Essai de choc non instrumenté

Le présent document spécifie une méthode de détermination de la résistance au choc Charpy des plastiques dans des conditions définies. De nombreux types d’éprouvettes et de configurations d’essai différents sont définis. Divers paramètres d’essai sont spécifiés selon le type de matière, le type d’éprouvette et le type d’entaille. La présente méthode peut être utilisée pour l’étude du comportement des types d’éprouvettes spécifiés soumises à des conditions de choc définies et pour l’estimation de la fragilité ou de la ténacité des éprouvettes dans les limites inhérentes aux conditions d’essai. Elle peut également être utilisée pour déterminer des résultats comparatifs propres à des types similaires de matériaux.

General Information

• Status: Not Published
• ICS: 83.080.01 - Plastics in general
• Technical Committee: ISO/TC 61/SC 2 - Mechanical behavior
• Drafting Committee: ISO/TC 61/SC 2 - Mechanical behavior
• Current Stage: 6000 - International Standard under publication
• Completion Date: 18-Apr-2023

Relations

• Revises: ISO 179-1:2010 - Plastics — Determination of Charpy impact properties — Part 1: Non-instrumented impact test
• Effective Date: 06-Jun-2022
• Consolidates: ISO/TS 20224-4:2020 - Molecular biomarker analysis — Detection of animal-derived materials in foodstuffs and feedstuffs by real-time PCR — Part 4: Chicken DNA detection method
• Effective Date: 06-Jun-2022

Standards Content (Sample)

20222023-02-1006
ISO/DISFDIS 179-1:20222023(E)
ISO TC 61/SC 2/WG 3
Secretariat: SAC
Plastics — Determination of Charpy impact properties — Part 1: Non-instrumented
impact test

Plastiques — Détermination des caractéristiques au choc Charpy —Partie 1: Essai de choc non

instrumenté
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ISO/FDIS 179-1:2023(E)
© ISO 20222023

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
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ISO/FDIS 179-1:2023(E)
Contents

Foreword ..................................................................................................................................................................... iv

1 Scope ................................................................................................................................................................ 1

2 Normative references ................................................................................................................................ 2

3 Terms and definitions ................................................................................................................................ 2

4 Principle ......................................................................................................................................................... 3

5 Apparatus ....................................................................................................................................................... 3

5.1 Test machine ................................................................................................................................................. 3

5.2 Micrometers and gauges ........................................................................................................................... 3

6 Test specimens ............................................................................................................................................. 4

6.1 Preparation ................................................................................................................................................... 4

6.1.1 Moulding and extrusion compounds ..................................................................................................... 4

6.1.2 Sheets .............................................................................................................................................................. 4

6.1.3 Long-fibre-reinforced materials ............................................................................................................. 4

6.1.4 Checking ......................................................................................................................................................... 7

6.1.5 Notching.......................................................................................................................................................... 7

6.2 Anisotropy ..................................................................................................................................................... 7

6.3 Shape and dimensions ............................................................................................................................... 7

6.3.1 Materials not exhibiting interlaminar shear fracture ..................................................................... 7

6.3.2 Materials exhibiting interlaminar shear fracture (e.g. long-fibre-reinforced

materials) ....................................................................................................................................................... 9

6.4 Number of test specimens ........................................................................................................................ 9

6.5 Definition of span between specimen supports, L .......................................................................... 10

6.6 Conditioning ................................................................................................................................................ 11

7 Procedure .................................................................................................................................................... 11

8 Calculation and expression of results ................................................................................................. 12

8.1 Unnotched specimens .............................................................................................................................. 12

8.2 Notched specimens ................................................................................................................................... 12

8.3 Statistical parameters .............................................................................................................................. 12

8.4 Significant figures ...................................................................................................................................... 12

9 Precision ....................................................................................................................................................... 13

10 Test report ................................................................................................................................................... 13

Annex A (informative) Additional methods for investigating the influence of surface effects ...... 15

Annex B (informative) Precision data .............................................................................................................. 17

B.1 General .......................................................................................................................................................... 17

B.2 Concept of r and R ...................................................................................................................................... 17

Annex C (informative) Determining the notch tip radius using a CCD microscope ........................... 19

Bibliography ............................................................................................................................................................. 22

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ISO/FDIS 179-1:2023(E)

Foreword ..................................................................................................................................................................... iv

Introduction ............................................................................................................................................................... vi

1 Scope ................................................................................................................................................................ 1

2 Normative references ................................................................................................................................. 1

3 Terms and definitions ................................................................................................................................ 2

4 Principle ......................................................................................................................................................... 3

5 Apparatus ....................................................................................................................................................... 3

5.1 Test machine ................................................................................................................................................. 3

5.2 Micrometers and gauges ........................................................................................................................... 3

6 Test specimens ............................................................................................................................................. 5

6.1 Preparation ................................................................................................................................................... 5

6.1.1 Moulding and extrusion compounds ..................................................................................................... 5

6.1.2 Sheets............................................................................................................................................................... 5

6.1.3 Long-fibre-reinforced materials ............................................................................................................. 5

6.1.4 Checking ....................................................................................................................................................... 11

6.1.5 Notching ........................................................................................................................................................ 11

6.2 Anisotropy ................................................................................................................................................... 12

6.3 Shape and dimensions ............................................................................................................................. 12

6.3.1 Materials not exhibiting interlaminar shear fracture ................................................................... 12

6.3.2 Materials exhibiting interlaminar shear fracture (e.g. long-fibre-reinforced

materials) ..................................................................................................................................................... 14

6.4 Number of test specimens ....................................................................................................................... 14

6.5 Span between specimen supports, L .................................................................................................... 15

6.6 Conditioning ................................................................................................................................................ 16

7 Procedure ..................................................................................................................................................... 17

8 Calculation and expression of results ................................................................................................. 18

8.1 Unnotched specimens .............................................................................................................................. 18

8.2 Notched specimens ................................................................................................................................... 18

8.3 Statistical parameters .............................................................................................................................. 18

8.4 Significant figures ...................................................................................................................................... 18

9 Precision ....................................................................................................................................................... 19

10 Test report ................................................................................................................................................... 19

Annex A (informative) Additional methods for investigating the influence of surface effects ..... 21

Annex B (informative) Precision data ............................................................................................................. 24

Annex C (informative) Determining the notch tip radius using a CCD microscope .......................... 28

Bibliography .............................................................................................................................................................. 32

iv © ISO 2023– All rights reserved
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ISO/FDIS 179-1:2023(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 61, Plastics, Subcommittee SC 2,

Mechanical behavior, in collaboration with the European Committee for Standardization (CEN)

Technical Committee CEN/TC 249, Plastics, in accordance with the Agreement on technical cooperation

between ISO and CEN (Vienna Agreement).

This third edition cancels and replaces the second edition (ISO 179-1:2010), which has been technically

revised.
The main changes are as follows:

— results of a round robin for unnotched specimens (see Annex B) have been added;

— reference to standard ISO 16012 (see the Bibliography and subclause 5.2) has been added;

— improvements of the micrometers and gauges subclause (see 5.2) have been addressed;

— symbols used in Formulae (1) and (2) have been reviewed and updated.
A list of all parts in the ISO 179 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.
© ISO 2023 – All rights reserved v
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ISO/FDIS 179-1:2023(E)
Introduction

The Charpy impact properties determination method described in the ISO 179 series has a greater

[1]

range of applicability than that given in ISO 180 and is more suitable for the testing of materials

showing interlaminar shear fracture or of materials exhibiting surface effects due to environmental

factors.
The method is suitable for use with the following range of materials:

— rigid thermoplastic moulding and extrusion materials (including filled and reinforced compounds

in addition to unfilled types) and rigid thermoplastics sheets;

— rigid thermosetting moulding materials (including filled and reinforced compounds) and rigid

thermosetting sheets (including laminates);

— fibre-reinforced thermosetting and thermoplastic composites incorporating unidirectional or

multi-directional reinforcements (such as mats, woven fabrics, woven rovings, chopped strands,

combination and hybrid reinforcements, rovings and milled fibres) or incorporating sheets made

from pre-impregnated materials (prepregs), including filled and reinforced compounds;

— thermotropic liquid-crystal polymers.

Notched samples are not normally suitable for use with rigid cellular materials, long-fibre-reinforced

composites or thermotropic liquid-crystal polymers. In these cases, unnotched samples may be used.

The method is suited to the use of specimens moulded to the chosen dimensions, machined from the

central portion of a standard multipurpose test specimen (see ISO 20753) or machined from finished or

semifinished products such as mouldings, laminates and extruded or cast sheet.
vi © ISO 2023– All rights reserved
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FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 179-1:2023(E)
Plastics — Determination of Charpy impact properties — Part 1:
Non-instrumented impact test
1 Scope

This document specifies a method for determining the Charpy impact strength of plastics under defined

conditions. A number of different types of specimen and test configurations are defined. Different test

parameters are specified according to the type of material, the type of test specimen and the type of

notch.

The method can be used to investigate the behaviour of specified types of specimen under the impact

conditions defined and for estimating the brittleness or toughness of specimens within the limitations

inherent in the test conditions. It can also be used for the determination of comparative data from

similar types of material.
32 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 291, Plastics — Standard atmospheres for conditioning and testing

ISO 293, Plastics — Compression moulding of test specimens of thermoplastic materials

ISO 294-1, Plastics — Injection moulding of test specimens of thermoplastic materials — Part 1: General

principles, and moulding of multipurpose and bar test specimens

ISO 294-3, Plastics — Injection moulding of test specimens of thermoplastic materials — Part 3: Small

plates

ISO 295, Plastics — Compression moulding of test specimens of thermosetting materials

ISO 1268-11, Fibre-reinforced plastics — Methods of producing test plates — Part 11: Injection moulding

of BMC and other long-fibre moulding compounds — Small plates
ISO 2818, Plastics — Preparation of test specimens by machining
ISO 20753, Plastics – Test specimens

ISO 10724-1, Plastics — Injection moulding of test specimens of thermosetting powder moulding

compounds (PMCs) — Part 1: General principles and moulding of multipurpose test specimens

© ISO 2023 – All rights reserved 1
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ISO/FDIS 179-1:2023(E)

ISO 13802, Plastics — Verification of pendulum impact-testing machines — Charpy, Izod and tensile

impact-testing
43 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: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
Charpy impact strength of unnotched specimens

impact energy absorbed in breaking an unnotched specimen, referred to the original cross-sectional

area of the specimen
Note 1 to entry: It is expressed in kilojoules per square metre (kJ/m ).
3.2
Charpy impact strength of notched specimens

impact energy absorbed in breaking a notched specimen, referred to the original cross-sectional area of

the specimen at the notch, where N = A, B or C, depending on the notch type
Note 1 to entry: See 6.3.1.1.2.
Note 2 to entry: It is expressed in kilojoules per square metre (kJ/m ).
3.3
edgewise impact

direction of blow parallel to the dimension b, with impact on the narrow longitudinal surface h × l of the

specimen
Note 1 to entry_: See Figure 1 a) and Figures 2 and 4.
3.4
flatwise impact

direction of blow parallel to the dimension h, with impact on the broad longitudinal surface b × l of the

specimen
Note 1 to entry: See Figure 1 b) and Figures 3 and 4.
3.5
normal direction of blow

impact with the direction of blow normal to the plane of reinforcement

2 © ISO 2023 – All rights reserved
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ISO/FDIS 179-1:2023(E)
Note 1 to entry: See Figure 4.
3.6
parallel direction of blow

impact with the direction of blow parallel to the plane of reinforcement

Note 1 to entry: See Figure 4.
54 Principle

The test specimen, supported near its ends as a horizontal beam, is impacted by a single blow of a

striker, with the line of impact midway between the supports, and bent at a high, nominally constant,

velocity.

In the case of edgewise impact with notched specimens, the line of impact is directly opposite the single

notch ([see Figure 1 a) and Figure 2).].

The method specifies preferred dimensions for the test specimen. Tests which are carried out on

specimens of different dimensions or with different notches, or specimens which are prepared under

different conditions, can produce results which are not comparable. Other factors, such as the energy

capacity of the apparatus, the impact velocity and the conditioning of the specimens can also influence

the results. Consequently, when comparative data are required, these factors mustshall be carefully

controlled and recorded.

The method is not intended to be used as a source of data for design calculations. Information on the

typical behaviour of a material can be obtained, however, by testing at different temperatures, by

varying the notch radius and/or the specimen thickness and by testing specimens prepared under

different conditions.
65 Apparatus
6.15.1 Test machine

The principles, characteristics and verification of suitable test machines are detailed in ISO 13802.

ISO 13802 describes partial verification and full verification. In the case of full verification, some items

are difficult to verify when the apparatus is assembled. Such verifications are assumed to be incumbent

on the manufacturer.
6.25.2 Micrometers and gauges

Micrometers and gauges shall allow to determine the relevant dimensions of the test specimens with an

uncertainty not larger than 0,02 mm. For the determination of the dimension b of notched test

specimens measuring tips appropriate for the contour of the notch shall be used. For general

information on the determination of test specimen dimensions, see ISO 16012.
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ISO/FDIS 179-1:2023(E)
a) Edgewise impact b) Flatwise impact
Key
1 direction of blow
2 rod of pendulum
3 test specimen
4 notch
5 support

Figure 1 — Striking edge and support blocks for type 1 test specimen at moment of impact

4 © ISO 2023 – All rights reserved
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ISO/FDIS 179-1:2023(E)
76 Test specimens
7.16.1 Preparation
7.1.16.1.1 Moulding and extrusion compounds

Specimens shall be prepared in accordance with the relevant material specification. The specimens

shall be either directly compression moulded in accordance with ISO 293 or ISO 295 or injection

moulded from the material in accordance with ISO 294-1, ISO 294-3 or ISO 10724-1, as appropriate, or

machined in accordance with ISO 2818 from sheet that has been compression or injection moulded

from the compound. Type 1 specimens may be cut from multipurpose test specimens complying with

ISO 20753, type A.
7.1.26.1.2 Sheets
Specimens shall be machined from sheets in accordance with ISO 2818.
7.1.36.1.3 Long-fibre-reinforced materials

A panel shall be prepared in accordance with ISO 1268-11 or another specified or agreed upon

preparation procedure. Specimens shall be machined in accordance with ISO 2818.
© ISO 2023 – All rights reserved 5
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ISO/FDIS 179-1:2023(E)
Key
1 direction of blow
Figure 2 — Charpy edgewise impact (e) with single-notched specimen
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ISO/FDIS 179-1:2023(E)
Key
© ISO 2023 – All rights reserved 7
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ISO/FDIS 179-1:2023(E)
1 direction of blow
Figure 3 — Charpy flatwise impact (f)
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ISO/FDIS 179-1:2023(E)
© ISO 2023 – All rights reserved 9
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ISO/FDIS 179-1:2023(E)
Key
1 direction of blow
10 © ISO 2023 – All rights reserved
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ISO/FDIS 179-1:2023(E)
e edgewise
f flatwise
n normal
p parallel

NOTE 1 Edgewise (e) and flatwise (f) indicate the direction of the blow with respect to the specimen thickness, h,

and specimen width, b. Normal (n) and parallel (p) indicate the direction of the blow with respect to the laminate

plane.

NOTE 2 The Charpy “fn” and “ep” tests are used for laminates, while both the Charpy “en” and “ep” tests are used

for other materials. The Charpy “fn” and “fp” tests are used for testing materials exhibiting surface effects.

Figure 4 — Scheme of designations describing the direction of blow
7.1.46.1.4 Checking

The specimens shall be free of twist and shall have mutually perpendicular parallel surfaces. The

surfaces and edges shall be free from scratches, pits, sink marks and flash.

The specimens shall be checked for conformity with these requirements by visual observation against

straightedges, set squares and flat plates, and by measuring with micrometer callipers.

Specimens showing measurable or observable departure from one or more of these requirements shall

be rejected or machined to proper size and shape before testing.
7.1.56.1.5 Notching

6.1.5.1 Machined notches shall be prepared in accordance with ISO 2818. The profile of the cutting

tooth shall be such as to produce in the specimen a notch of the contour and depth as defined in Table 2

and shown in Figure 5, at right angles to its principal axes (see Note).
NOTE The radius of the notch tip can be measured by the method given in Annex C.

6.1.5.2 Specimens with moulded-in notches may be used if specified for the material being tested

(see Note).

NOTE Specimens with moulded-in notches do not give results comparable to those obtained from specimens

with machined notches.
© ISO 2023 – All rights reserved 11
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ISO/FDIS 179-1:2023(E)
a) Type A b) Type B c) Type C
Radius of notch tip Radius of notch tip Radius of notch tip
rN = (0,25 ± 0,05) mm rN = (1,00 ± 0,05) mm rN = (0,10 ± 0,02) mm
Figure 5 — Notch types
7.26.2 Anisotropy

Certain types of sheet or panel material or specimen taken from injection-moulded plates can show

different impact properties, depending on the direction in the plane of the sheet or panel. In such cases,

it is customary to cut groups of test specimens with their major axes respectively parallel and

perpendicular to the direction of some feature of the sheet or panel which is either visible or inferred

from knowledge of the method of manufacture.
7.36.3 Shape and dimensions
7.3.16.3.1 Materials not exhibiting interlaminar shear fracture
7.3.1.16.3.1.1 Moulding and extrusion compounds

6.3.1.1.1 Type 1 test specimens, unnotched or with one of three different types of notch, shall be used

as specified in Tables 1 and 2 and shown in Figures 2 and 5. The notch shall be located at the centre of

the specimen. Type 1 specimens (see Table 1) may be taken from the central part of the type A

multipurpose test specimen specified in ISO 20753.

Table 1 — Specimen types, specimen dimensions and spans between specimen supports

(see Figures 2 and 6)supports
Dimensions in millimetres
a a a
Specimen type Length Width Thickness Span
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ISO/FDIS 179-1:2023(E)
l b h L
+0,5 +0,5
Field Code Changed
62 62
1 80 ± 2 10,0 ± 0,2 4,0 ± 0,2
−0,0 −0,0
b c d
2 25h 10 or 15 3 20h
3 11h or 13h 10,0 ± 0,2 4,0 ± 0,2 6h or 8h

The specimen dimensions (thickness, h, width, b, and length, l) are defined by h < b < l.

Specimen types 2 and 3 shall be used only for materials described in 6.3.2.

10 mm for materials reinforced with a fine structure, 15 mm for those with a large stitch structure (see 6.3.2.2).

Preferred thickness. If the specimen is cut from a sheet or a piece, h shall be equal to the thickness of the sheet or piece, up

to 10,2 mm (see 6.3.1.2)).
See Figures 2 and 6.
Table 2 — Method designat
...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 179-1
ISO/TC 61/SC 2
Plastics — Determination of Charpy
Secretariat: SAC
impact properties —
Voting begins on:
2023-02-20
Part 1:
Voting terminates on:
Non-instrumented impact test
2023-04-17
Plastiques — Détermination des caractéristiques au choc Charpy —
Partie 1: Essai de choc non instrumenté
ISO/CEN PARALLEL PROCESSING
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 179-1:2023(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 2023
---------------------- Page: 1 ----------------------
ISO/FDIS 179-1:2023(E)
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 179-1
ISO/TC 61/SC 2
Plastics — Determination of Charpy
Secretariat: SAC
impact properties —
Voting begins on:
Part 1:
Voting terminates on:
Non-instrumented impact test
Plastiques — Détermination des caractéristiques au choc Charpy —
Partie 1: Essai de choc non instrumenté
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023
ISO/CEN PARALLEL PROCESSING

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 179-1:2023(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
© ISO 2023 – All rights reserved
NATIONAL REGULATIONS. © ISO 2023
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ISO/FDIS 179-1:2023(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction .................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ..................................................................................................................................................................................... 1

3 Terms and definitions .................................................................................................................................................................................... 1

4 Principle ........................................................................................................................................................................................................................ 2

5 Apparatus .................................................................................................................................................................................................................... 3

5.1 Test machine ............................................................................................................................................................................................. 3

5.2 Micrometers and gauges ................................................................................................................................................................ 3

6 Test specimens ....................................................................................................................................................................................................... 4

6.1 Preparation ................................................................................................................................................................................................ 4

6.1.1 Moulding and extrusion compounds ................................................................................................................ 4

6.1.2 Sheets ........................................................................................................................................................................................... 4

6.1.3 Long-fibre-reinforced materials ................................... ........................................................................................ 4

6.1.4 Checking ........................................................................................................................................... .......................................... 7

6.1.5 Notching ..................................................................................................................................................................................... 7

6.2 Anisotropy .................................................................................................................................................................................................. 7

6.3 Shape and dimensions ..................................................................................................................................................................... 8

6.3.1 Materials not exhibiting interlaminar shear fracture ...................................................................... 8

6.3.2 Materials exhibiting interlaminar shear fracture (e.g. long-fibre-reinforced

materials) .................................................................................................................................................................................. 9

6.4 Number of test specimens ............................................................................................................................................................ 9

6.5 Span between specimen supports, L ................................................................................................................................ 10

6.6 Conditioning........................................................................................................................................................................................... 11

7 Procedure .................................................................................................................................................................................................................11

8 Calculation and expression of results ........................................................................................................................................12

8.1 Unnotched specimens ...................................................................................................................................................................12

8.2 Notched specimens ..........................................................................................................................................................................12

8.3 Statistical parameters................................................................................................................................................................... 12

8.4 Significant figures.............................................................................................................................................................................12

9 Precision ....................................................................................................................................................................................................................12

10 Test report ...............................................................................................................................................................................................................12

Annex A (informative) Additional methods for investigating the influence of surface effects .........15

Annex B (informative) Precision data .............................................................................................................................................................17

Annex C (informative) Determining the notch tip radius using a CCD microscope ........................................19

Bibliography .............................................................................................................................................................................................................................22

iii
© ISO 2023 – All rights reserved
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ISO/FDIS 179-1:2023(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 61, Plastics, Subcommittee SC 2,

Mechanical behavior, in collaboration with the European Committee for Standardization (CEN) Technical

Committee CEN/TC 249, Plastics, in accordance with the Agreement on technical cooperation between

ISO and CEN (Vienna Agreement).

This third edition cancels and replaces the second edition (ISO 179-1:2010), which has been technically

revised.
The main changes are as follows:

— results of a round robin for unnotched specimens (see Annex B) have been added;

— reference to standard ISO 16012 (see the Bibliography and subclause 5.2) has been added;

— improvements of the micrometers and gauges subclause (see 5.2) have been addressed;

— symbols used in Formulae (1) and (2) have been reviewed and updated.
A list of all parts in the ISO 179 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.
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ISO/FDIS 179-1:2023(E)
Introduction

The Charpy impact properties determination method described in the ISO 179 series has a greater range

[1]

of applicability than that given in ISO 180 and is more suitable for the testing of materials showing

interlaminar shear fracture or of materials exhibiting surface effects due to environmental factors.

The method is suitable for use with the following range of materials:

— rigid thermoplastic moulding and extrusion materials (including filled and reinforced compounds

in addition to unfilled types) and rigid thermoplastics sheets;

— rigid thermosetting moulding materials (including filled and reinforced compounds) and rigid

thermosetting sheets (including laminates);

— fibre-reinforced thermosetting and thermoplastic composites incorporating unidirectional or

multi-directional reinforcements (such as mats, woven fabrics, woven rovings, chopped strands,

combination and hybrid reinforcements, rovings and milled fibres) or incorporating sheets made

from pre-impregnated materials (prepregs), including filled and reinforced compounds;

— thermotropic liquid-crystal polymers.

Notched samples are not normally suitable for use with rigid cellular materials, long-fibre-reinforced

composites or thermotropic liquid-crystal polymers. In these cases, unnotched samples may be used.

The method is suited to the use of specimens moulded to the chosen dimensions, machined from the

central portion of a standard multipurpose test specimen (see ISO 20753) or machined from finished or

semifinished products such as mouldings, laminates and extruded or cast sheet.
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FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 179-1:2023(E)
Plastics — Determination of Charpy impact properties —
Part 1:
Non-instrumented impact test
1 Scope

This document specifies a method for determining the Charpy impact strength of plastics under defined

conditions. A number of different types of specimen and test configurations are defined. Different test

parameters are specified according to the type of material, the type of test specimen and the type of

notch.

The method can be used to investigate the behaviour of specified types of specimen under the impact

conditions defined and for estimating the brittleness or toughness of specimens within the limitations

inherent in the test conditions. It can also be used for the determination of comparative data from

similar types of material.
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 291, Plastics — Standard atmospheres for conditioning and testing

ISO 293, Plastics — Compression moulding of test specimens of thermoplastic materials

ISO 294-1, Plastics — Injection moulding of test specimens of thermoplastic materials — Part 1: General

principles, and moulding of multipurpose and bar test specimens

ISO 294-3, Plastics — Injection moulding of test specimens of thermoplastic materials — Part 3: Small

plates

ISO 295, Plastics — Compression moulding of test specimens of thermosetting materials

ISO 1268-11, Fibre-reinforced plastics — Methods of producing test plates — Part 11: Injection moulding of

BMC and other long-fibre moulding compounds — Small plates
ISO 2818, Plastics — Preparation of test specimens by machining

ISO 10724-1, Plastics — Injection moulding of test specimens of thermosetting powder moulding compounds

(PMCs) — Part 1: General principles and moulding of multipurpose test specimens

ISO 13802, Plastics — Verification of pendulum impact-testing machines — Charpy, Izod and tensile

impact-testing
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: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
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ISO/FDIS 179-1:2023(E)
3.1
Charpy impact strength of unnotched specimens

impact energy absorbed in breaking an unnotched specimen, referred to the original cross-sectional

area of the specimen
Note 1 to entry: It is expressed in kilojoules per square metre (kJ/m ).
3.2
Charpy impact strength of notched specimens

impact energy absorbed in breaking a notched specimen, referred to the original cross-sectional area

of the specimen at the notch, where N = A, B or C, depending on the notch type
Note 1 to entry: See 6.3.1.1.2.
Note 2 to entry: It is expressed in kilojoules per square metre (kJ/m ).
3.3
edgewise impact

direction of blow parallel to the dimension b, with impact on the narrow longitudinal surface h × l of the

specimen
Note 1 to entry: See Figure 1 a) and Figures 2 and 4.
3.4
flatwise impact

direction of blow parallel to the dimension h, with impact on the broad longitudinal surface b × l of the

specimen
Note 1 to entry: See Figure 1 b) and Figures 3 and 4.
3.5
normal direction of blow

impact with the direction of blow normal to the plane of reinforcement

Note 1 to entry: See Figure 4.
3.6
parallel direction of blow

impact with the direction of blow parallel to the plane of reinforcement

Note 1 to entry: See Figure 4.
4 Principle

The test specimen, supported near its ends as a horizontal beam, is impacted by a single blow of a

striker, with the line of impact midway between the supports, and bent at a high, nominally constant,

velocity.

In the case of edgewise impact with notched specimens, the line of impact is directly opposite the single

notch [see Figure 1 a) and Figure 2].

The method specifies preferred dimensions for the test specimen. Tests which are carried out on

specimens of different dimensions or with different notches, or specimens which are prepared under

different conditions, can produce results which are not comparable. Other factors, such as the energy

capacity of the apparatus, the impact velocity and the conditioning of the specimens can also influence

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ISO/FDIS 179-1:2023(E)

the results. Consequently, when comparative data are required, these factors shall be carefully

controlled and recorded.

The method is not intended to be used as a source of data for design calculations. Information on the

typical behaviour of a material can be obtained, however, by testing at different temperatures, by

varying the notch radius and/or the specimen thickness and by testing specimens prepared under

different conditions.
5 Apparatus
5.1 Test machine

The principles, characteristics and verification of suitable test machines are detailed in ISO 13802.

ISO 13802 describes partial verification and full verification. In the case of full verification, some items

are difficult to verify when the apparatus is assembled. Such verifications are assumed to be incumbent

on the manufacturer.
5.2 Micrometers and gauges

Micrometers and gauges shall allow to determine the relevant dimensions of the test specimens

with an uncertainty not larger than 0,02 mm. For the determination of the dimension b of notched

test specimens measuring tips appropriate for the contour of the notch shall be used. For general

information on the determination of test specimen dimensions, see ISO 16012.
a) Edgewise impact b) Flatwise impact
Key
1 direction of blow
2 rod of pendulum
3 test specimen
4 notch
5 support

Figure 1 — Striking edge and support blocks for type 1 test specimen at moment of impact

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ISO/FDIS 179-1:2023(E)
6 Test specimens
6.1 Preparation
6.1.1 Moulding and extrusion compounds

Specimens shall be prepared in accordance with the relevant material specification. The specimens

shall be either directly compression moulded in accordance with ISO 293 or ISO 295 or injection

moulded from the material in accordance with ISO 294-1, ISO 294-3 or ISO 10724-1, as appropriate,

or machined in accordance with ISO 2818 from sheet that has been compression or injection moulded

from the compound. Type 1 specimens may be cut from multipurpose test specimens complying with

ISO 20753, type A.
6.1.2 Sheets
Specimens shall be machined from sheets in accordance with ISO 2818.
6.1.3 Long-fibre-reinforced materials

A panel shall be prepared in accordance with ISO 1268-11 or another specified or agreed upon

preparation procedure. Specimens shall be machined in accordance with ISO 2818.
Key
1 direction of blow
Figure 2 — Charpy edgewise impact (e) with single-notched specimen
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ISO/FDIS 179-1:2023(E)
Key
1 direction of blow
Figure 3 — Charpy flatwise impact (f)
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ISO/FDIS 179-1:2023(E)
Key
1 direction of blow
e edgewise
f flatwise
n normal
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ISO/FDIS 179-1:2023(E)
p parallel

NOTE 1 Edgewise (e) and flatwise (f) indicate the direction of the blow with respect to the specimen

thickness, h, and specimen width, b. Normal (n) and parallel (p) indicate the direction of the blow with respect to

the laminate plane.

NOTE 2 The Charpy “fn” and “ep” tests are used for laminates, while both the Charpy “en” and “ep” tests are

used for other materials. The Charpy “fn” and “fp” tests are used for testing materials exhibiting surface effects.

Figure 4 — Scheme of designations describing the direction of blow
6.1.4 Checking

The specimens shall be free of twist and shall have mutually perpendicular parallel surfaces. The

surfaces and edges shall be free from scratches, pits, sink marks and flash.

The specimens shall be checked for conformity with these requirements by visual observation against

straightedges, set squares and flat plates, and by measuring with micrometer callipers.

Specimens showing measurable or observable departure from one or more of these requirements shall

be rejected or machined to proper size and shape before testing.
6.1.5 Notching

6.1.5.1 Machined notches shall be prepared in accordance with ISO 2818. The profile of the cutting

tooth shall be such as to produce in the specimen a notch of the contour and depth as defined in Table 2

and shown in Figure 5, at right angles to its principal axes (see Note).
NOTE The radius of the notch tip can be measured by the method given in Annex C.

6.1.5.2 Specimens with moulded-in notches may be used if specified for the material being tested

(see Note).

NOTE Specimens with moulded-in notches do not give results comparable to those obtained from specimens

with machined notches.
a) Type A b) Type B c) Type C
Radius of notch tip Radius of notch tip Radius of notch tip
r = (0,25 ± 0,05) mm r = (1,00 ± 0,05) mm r = (0,10 ± 0,02) mm
N N N
Figure 5 — Notch types
6.2 Anisotropy

Certain types of sheet or panel material or specimen taken from injection-moulded plates can show

different impact properties, depending on the direction in the plane of the sheet or panel. In such

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ISO/FDIS 179-1:2023(E)

cases, it is customary to cut groups of test specimens with their major axes respectively parallel and

perpendicular to the direction of some feature of the sheet or panel which is either visible or inferred

from knowledge of the method of manufacture.
6.3 Shape and dimensions
6.3.1 Materials not exhibiting interlaminar shear fracture
6.3.1.1 Moulding and extrusion compounds

6.3.1.1.1 Type 1 test specimens, unnotched or with one of three different types of notch, shall be

used as specified in Tables 1 and 2 and shown in Figures 2 and 5. The notch shall be located at the

centre of the specimen. Type 1 specimens (see Table 1) may be taken from the central part of the type A

multipurpose test specimen specified in ISO 20753.

Table 1 — Specimen types, specimen dimensions and spans between specimen supports

Dimensions in millimetres
a a a
Length Width Thickness Span
Specimen type
l b h L
+05,
1 80 ± 2 10,0 ± 0,2 4,0 ± 0,2 62
−00,
b c d
2 25h 10 or 15 3 20h
3 11h or 13h 10,0 ± 0,2 4,0 ± 0,2 6h or 8h

The specimen dimensions (thickness, h, width, b, and length, l) are defined by h < b < l.

Specimen types 2 and 3 shall be used only for materials described in 6.3.2.

10 mm for materials reinforced with a fine structure, 15 mm for those with a large stitch structure (see 6.3.2.2).

Preferred thickness. If the specimen is cut from a sheet or a piece, h shall be equal to the thickness of the sheet or piece,

up to 10,2 mm (see 6.3.1.2).
See Figures 2 and 6.

Table 2 — Method designations, specimen types, notch types and notch dimensions —

Materials not exhibiting interlaminar shear fracture
Dimensions in millimetres
Remaining
Notch tip
Specimen width, b ,
a radius, r N
Method designation Blow direction Notch type N
type at notch tip
(see Figure 5)
(see Figure 2)
ISO 179-1/1eA A 0,25 ± 0,05 8,0 ± 0,2
ISO 179-1/1eB B 1,00 ± 0,05 8,0 ± 0,2
Edgewise
ISO 179-1/1eC 1 C 0,10 ± 0,02 8,0 ± 0,2
ISO 179-1/1eU Unnotched
ISO 179-1/1fU Flatwise Unnotched

If specimens are taken from sheet or products, the thickness of the sheet or product shall be added to the designation.

Unreinforced specimens shall not be tested with their machined surface under tension.

Preferred method.
Especially for the study of surface effects (see 6.3.1.1.3).

6.3.1.1.2 The preferred type of notch is type A (see Table 2 and Figure 5). For most materials,

unnotched specimens or specimens with a single type A notch tested by edgewise impact (see 3.3) are

suitable. If specimens with a type A notch do not break during the test, specimens with a type C notch

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ISO/FDIS 179-1:2023(E)

shall be used. If information on the notch sensitivity of the material is desired, specimens with notch

types A, B and C shall be tested.

6.3.1.1.3 Unnotched or double-notched specimens tested by flatwise impact (see 3.4) can be used to

study surface effects (see Annex A).
6.3.1.2 Sheet materials

The recommended value of the thickness, h, is 4 mm. If the specimen is cut from a sheet or a piece taken

from a structure, the thickness of the specimen, up to 10,2 mm, shall be the same as the thickness of the

sheet or the structure.

Specimens taken from pieces thicker than 10,2 mm shall be machined to (10 ± 0,2) mm from one surface,

provided that the sheet is homogeneous in its thickness and contains only one type of reinforcement

uniformly distributed. If unnotched or double-notched specimens are tested by flatwise impact, the

original surface shall be tested under tension.

6.3.2 Materials exhibiting interlaminar shear fracture (e.g. long-fibre-reinforced materials)

6.3.2.1 Unnotched specimens of type 2 or 3 are used. Apart from the thickness, the specimen

dimensions are not specified. The most important parameter is the ratio of the span between the

specimen supports to the specimen dimension in the direction of the blow (see Table 1).

Usually specimens are tested in the normal direction (see Figure 4).

6.3.2.2 “Flatwise normal” testing (see Figure 4): the width of specimen shall be 10 mm for materials

reinforced with a fine structure (thin fabrics and parallel yarns) and 15 mm for materials reinforced

with a large stitch structure (roving fabrics) or an irregularly manufactured structure.

6.3.2.3 “Edgewise parallel” testing (see Figure 4): when testing specimens in the parallel direction,

the specimen dimension perpendicular to the blow direction shall be the thickness of the sheet from

which the specimen was cut.

6.3.2.4 The length, l, of the specimen shall be chosen to give a span-to-thickness ratio, L/h, of 20 for

type 2 specimens and 6 for type 3 specimens although, if the apparatus does not allow a ratio L/h = 6, a

ratio L/h = 8 may be used, especially for thin sheets, as indicated in Table 1.

6.3.2.5 With type 2 specimens, tensile-type failure occurs; with type 3 specimens, interlaminar shear

failure of the sheet usually occurs. The different types of failure which can occur are summarized in

Table 3.

NOTE In some cases (thin-fabric reinforcement), shear failure does not occur. In the case of type 3 specimens,

the fracture starts as a single or multiple shear failure and continues as tensile failure.

6.4 Number of test specimens

6.4.1 Unless otherwise specified in the standard for the material being tested, a set consisting of

10 specimens shall be tested. When
...