SIST EN ISO 527-1:2019

Plastics - Determination of tensile properties - Part 1: General principles (ISO 527-1:2019)

1.1    This document specifies the general principles for determining the tensile properties of plastics and plastic composites under defined conditions. Several different types of test specimen are defined to suit different types of material which are detailed in subsequent parts of ISO 527.
1.2    The methods are used to investigate the tensile behaviour of the test specimens and for determining the tensile strength, tensile modulus and other aspects of the tensile stress/strain relationship under the conditions defined.
1.3    The methods are selectively suitable for use with the following materials:
—          rigid and semi-rigid moulding, extrusion and cast thermoplastic materials, including filled and reinforced compounds in addition to unfilled types; rigid and semi-rigid thermoplastics sheets and films;
—          rigid and semi-rigid thermosetting moulding materials, including filled and reinforced compounds; rigid and semi-rigid thermosetting sheets, including laminates;
—          fibre-reinforced thermosets and thermoplastic composites incorporating unidirectional or non-unidirectional reinforcements, such as mat, woven fabrics, woven rovings, chopped strands, combination and hybrid reinforcement, rovings and milled fibres; sheet made from pre-impregnated materials (prepregs);
—          thermotropic liquid crystal polymers.
The methods are not normally suitable for use with rigid cellular materials, for which ISO 1926 is used, or for sandwich structures containing cellular materials.

Kunststoffe - Bestimmung der Zugeigenschaften - Teil 1: Allgemeine Grundsätze (ISO 527-1:2019)

1.1 Dieses Dokument legt die allgemeinen Grundsätze zur Bestimmung der Zugeigenschaften von Kunst-stoffen und Kunststoff-Verbundwerkstoffen unter festgelegten Bedingungen fest. Mehrere verschiedene Probekörpertypen sind für unterschiedliche Werkstoffarten festgelegt, die in den folgenden Teilen von ISO 527 näher beschrieben werden.
1.2 Die Verfahren werden verwendet, um das Zugverformungsverhalten von Probekörpern zu untersu-chen und die Zugfestigkeit, den Zugmodul und andere Gesichtspunkte der Zugspannungs-/Dehnungs-Bezie-hung unter festgelegten Bedingungen zu ermitteln.
1.3 Die Verfahren sind speziell zur Anwendung bei folgenden Werkstoffgruppen geeignet:
- steife und halbsteife thermoplastische Spritzguss-, Extrusions- und Gussformmassen, einschließlich gefüllter und verstärkter Verbunde als Ergänzung zu ungefüllten Sorten; steife und halbsteife thermo-plastische Platten und Folien;
- steife und halbsteife duroplastische Formmassen, einschließlich gefüllter und verstärkter Verbunde; steife und halbsteife duroplastische Platten einschließlich Schichtstoffe;
- faserverstärkte duroplastische und thermoplastische Verbundwerkstoffe mit unidirektionaler oder nichtunidirektionaler Verstärkung, wie Matten, Vliese und Gelege, Gewebe, Rovinggewebe, Kombina-tions- und Mischverstärkung, Stränge (Rovings) und Kurzfasern; Tafeln aus vorgetränkten Werkstoffen (Prepregs);
- thermotrope flüssigkristalline Polymere.
Die Verfahren sind üblicherweise nicht zur Anwendung mit harten Schaumstoffen, für die ISO 1926 ange-wendet wird, oder für Schichtstoff-Verbundwerkstoffe mit Schaumstoffkern geeignet.

Plastiques - Détermination des propriétés en traction - Partie 1: Principes généraux (ISO 527-1:2019)

1.1    Le présent document spécifie les principes généraux pour la détermination des propriétés en traction des plastiques et des composites en plastique dans des conditions définies. Plusieurs types différents d'éprouvettes sont définis en fonction des différents types de matériaux qui sont énumérés dans les parties suivantes de I'ISO 527.
1.2    Les méthodes sont utilisées pour étudier le comportement en traction des éprouvettes par la détermination de la résistance en traction, du module d'élasticité en traction et d'autres aspects de la relation contrainte/déformation en traction dans des conditions définies.
1.3    Les méthodes conviennent sélectivement aux matériaux suivants:
—          matières thermoplastiques rigides et semi-rigides pour moulage, extrusion et coulée, y compris les compositions chargées et renforcées en plus des types non chargés; feuilles et films en thermoplastiques rigides et semi-rigides;
—          matières thermodurcissables rigides et semi-rigides pour moulage, y compris les compositions chargées et renforcées; feuilles thermodurcissables rigides et semi-rigides, y compris les stratifiés;
—          composites thermoplastiques et thermodurcissables renforcés de fibres comportant des renforts unidirectionnels et multidirectionnels tels que mats, tissus, tissus stratifils, fils coupés, combinaisons de renforcements et hybrides, stratifils et fibres broyées; feuilles réalisées à partir de matières préimprégnées (préimprégnés);
—          polymères à cristaux liquides thermotropes.
En principe, les méthodes ne peuvent pas être appliquées aux matériaux alvéolaires rigides, pour lesquels l'ISO 1926 est utilisée, ou aux structures sandwichs contenant des matériaux alvéolaires.

Polimerni materiali - Ugotavljanje nateznih lastnosti - 1. del: Splošna načela (ISO 527-1:2019)

Ta dokument določa splošna načela za ugotavljanje nateznih lastnosti polimernih materialov in polimernih kompozitov pri določenih pogojih. Opredeljenih je več vrst preskušancev, da se zajamejo različne vrste materialov, ki so podrobno opisane v poznejših delih standarda ISO 527. Uporabljene so metode za preučevanje nateznih lastnosti preskušancev ter za ugotavljanje natezne trdnosti, nateznega modula in drugih vidikov razmerja natezna napetost/deformacija pri določenih pogojih. Metode so selektivno ustrezne za naslednje materiale:  – trdi in poltrdi plastomerni materiali za oblikovanje, ekstrudiranje in vlivanje, vključno s polnjenimi in ojačanimi spojinami poleg nepolnjenih vrst; trdi in poltrdi plastomerni trakovi in filmi; – trdi in poltrdi termoreaktivni materiali za oblikovanje, vključno s polnjenimi in ojačanimi spojinami; trdi in poltrdi termoreaktivni trakovi, vključno z laminati; – z vlakni ojačani termoreaktivni in plastomerni kompoziti, ki vsebujejo enosmerne ali večsmerne ojačitve, kot so mati, tkanine, tkani rovingi, rezane niti, kombinacijske in hibridne ojačitve, rovingi in brušena vlakna; trakovi iz predhodno impregniranih materialov; – termotropni polimeri iz tekočih kristalov. Metode običajno niso primerne za trde penjene materiale, za katere se uporablja standard ISO 1926, ali za strukture tipa »sendvič«, ki vsebujejo penjene materiale.

General Information

• Status: Published
• Public Enquiry End Date: 30-Sep-2018
• Publication Date: 03-Oct-2019
• ICS: 83.080.01 - Plastics in general
• Technical Committee: IPMA - Polimer materials and products
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Oct-2019
• Due Date: 06-Dec-2019
• Completion Date: 04-Oct-2019
• Ref Project: EN ISO 527-1:2019 - Plastics - Determination of tensile properties - Part 1: General principles (ISO 527-1:2019)

Relations

• Replaces: SIST EN ISO 527-1:2012 - Plastics - Determination of tensile properties - Part 1: General principles (ISO 527-1:2012)
• Effective Date: 25-Sep-2019
• Revised: SIST EN ISO 527-1:2012 - Plastics - Determination of tensile properties - Part 1: General principles (ISO 527-1:2012)
• Effective Date: 23-May-2018

Overview

EN ISO 527-1:2019 - "Plastics - Determination of tensile properties - Part 1: General principles" (CEN adoption of ISO 527-1:2019) sets the general principles and requirements for tensile testing of plastics and plastic composites. It defines test objectives, specimen types, apparatus and measurement methods used to determine key tensile properties such as tensile strength, tensile modulus, and the stress–strain relationship under specified conditions. This edition supersedes EN ISO 527-1:2012 and aligns with the wider ISO 527 series for tensile testing.

Key topics and technical requirements

• Scope and applicability: Methods are selectively suitable for rigid and semi-rigid thermoplastics and thermosets, filled/reinforced compounds, fibre-reinforced composites (unidirectional and non‑unidirectional), prepregs and thermotropic liquid crystal polymers. Not normally suitable for rigid cellular materials (see ISO 1926) or sandwich structures containing cellular cores.
• Apparatus and measurement: Requirements for testing machines, grips, force indicators, extensometers (strain indicators), test speeds and data recording. Annex C includes calibration requirements for tensile modulus determination.
• Specimens and preparation: Definitions of specimen shapes, dimensions and preparation, gauge marks, checking for anisotropy and conditioning prior to testing.
• Test procedure: Guidance on test atmosphere, gripping, prestress, extensometer setting, selected test speeds and recording of data.
• Calculations and reporting: Methods for calculating stress, strain (extensometer-based and nominal), tensile modulus (chord and regression slopes), Poisson’s ratio, statistical parameters and required test report contents.
• Accuracy and precision: Updates on extensometer accuracy (for gauge lengths L ≤ 50 mm the accuracy is set to ±1 µm), precision statements and informative annexes on strain at yield and extensometer accuracy for Poisson’s ratio.

Practical applications

• Material characterization and comparison (tensile strength, stiffness)
• Product development and R&D for plastics and composite components
• Quality control and acceptance testing in manufacturing
• Validation of simulation inputs (material models using tensile modulus and stress–strain curves)
• Compliance and certification where tensile properties are specified

Who uses this standard

• Materials engineers and R&D laboratories
• Test laboratories and quality assurance teams
• Manufacturers of plastics, composites and molded/extruded products
• Certification bodies and regulatory assessors

Related standards

• ISO 527 (other parts) - detailed specimen types and methods (see the ISO 527 series)
• ISO 1926 - tensile testing of rigid cellular plastics (where EN ISO 527-1 is not applicable)
• National adoptions: EN ISO 527-1:2019 replaces EN ISO 527-1:2012

Keywords: EN ISO 527-1:2019, tensile properties, plastics tensile testing, tensile modulus, tensile strength, plastic composites, ISO 527.

Standards Content (Sample)

SLOVENSKI STANDARD
01-december-2019
Nadomešča:
SIST EN ISO 527-1:2012
Polimerni materiali - Ugotavljanje nateznih lastnosti - 1. del: Splošna načela (ISO
527-1:2019)
Plastics - Determination of tensile properties - Part 1: General principles (ISO 527-
1:2019)
Kunststoffe - Bestimmung der Zugeigenschaften - Teil 1: Allgemeine Grundsätze (ISO
527-1:2019)
Plastiques - Détermination des propriétés en traction - Partie 1: Principes généraux (ISO
527-1:2019)
Ta slovenski standard je istoveten z: EN ISO 527-1:2019
ICS:
83.080.01 Polimerni materiali na Plastics in general
splošno
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 527-1
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2019
EUROPÄISCHE NORM
ICS 83.080.01 Supersedes EN ISO 527-1:2012
English Version
Plastics - Determination of tensile properties - Part 1:
General principles (ISO 527-1:2019)
Plastiques - Détermination des propriétés en traction - Kunststoffe - Bestimmung der Zugeigenschaften - Teil
Partie 1: Principes généraux (ISO 527-1:2019) 1: Allgemeine Grundsätze (ISO 527-1:2019)
This European Standard was approved by CEN on 20 July 2019.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 527-1:2019 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 527-1:2019) has been prepared by Technical Committee ISO/TC 61 "Plastics" in
collaboration with Technical Committee CEN/TC 249 “Plastics” the secretariat of which is held by NBN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by March 2020, and conflicting national standards shall
be withdrawn at the latest by March 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 527-1:2012.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 527-1:2019 has been approved by CEN as EN ISO 527-1:2019 without any modification.

INTERNATIONAL ISO
STANDARD 527-1
Third edition
2019-07
Plastics — Determination of tensile
properties —
Part 1:
General principles
Plastiques — Détermination des propriétés en traction —
Partie 1: Principes généraux
Reference number
ISO 527-1:2019(E)
©
ISO 2019
ISO 527-1:2019(E)
© ISO 2019
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]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

ISO 527-1:2019(E)
Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Principle and methods . 6
4.1 Principle . 6
4.2 Method . 6
5 Apparatus . 7
5.1 Testing machine . 7
5.1.1 General. 7
5.1.2 Test speeds . 7
5.1.3 Grips . . . 7
5.1.4 Force indicator . 8
5.1.5 Strain indicator . . 8
5.1.6 Recording of data . . .10
5.2 Devices for measuring width and thickness of the test specimens .11
6 Test specimens.11
6.1 Shape and dimensions .11
6.2 Preparation of specimens .11
6.3 Gauge marks .11
6.4 Checking the test specimens .11
6.5 Anisotropy .12
7 Number of test specimens .12
8 Conditioning .13
9 Procedure.13
9.1 Test atmosphere .13
9.2 Dimensions of test specimen .13
9.3 Gripping .13
9.4 Prestresses .14
9.5 Setting of extensometers .14
9.6 Test speed .14
9.7 Recording of data .15
10 Calculation and expression of results .15
10.1 Stress .15
10.2 Strain .15
10.2.1 Strains determined with an extensometer .15
10.2.2 Nominal strain .16
10.3 Tensile modulus .17
10.3.1 General.17
10.3.2 Chord slope .17
10.3.3 Regression slope .17
10.4 Poisson's ratio .17
10.5 Statistical parameters .18
10.6 Significant figures .18
11 Precision .18
12 Test report .18
Annex A (informative) Determination of strain at yield .20
Annex B (informative) Extensometer accuracy for the determination of Poisson's ratio .23
ISO 527-1:2019(E)
Annex C (normative) Calibration requirements for the determination of the tensile modulus .24
Bibliography .26
iv © ISO 2019 – All rights reserved

ISO 527-1:2019(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 on 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 the following
URL: www .iso .org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 2,
Mechanical properties.
This third edition cancels and replaces the second edition (ISO 527-1:2012), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— an error in Figure 1 concerning ε has been removed;
tM
— the inconsistency concerning the accuracy of the elongation used in the calculation of the tensile
modulus between 5.1.5.1, Figure 1 and Annex C has been removed. For gauge lengths L ≤ 50 mm,
the accuracy is set to ±1 µm;
— the normative references (see Clause 2) have been updated;
— minor editorial changes have been applied;
— language has been clarified.
A list of all parts in the ISO 527 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.
INTERNATIONAL STANDARD ISO 527-1:2019(E)
Plastics — Determination of tensile properties —
Part 1:
General principles
1 Scope
1.1 This document specifies the general principles for determining the tensile properties of plastics
and plastic composites under defined conditions. Several different types of test specimen are defined to
suit different types of material which are detailed in subsequent parts of ISO 527.
1.2 The methods are used to investigate the tensile behaviour of the test specimens and for determining
the tensile strength, tensile modulus and other aspects of the tensile stress/strain relationship under the
conditions defined.
1.3 The methods are selectively suitable for use with the following materials:
— rigid and semi-rigid moulding, extrusion and cast thermoplastic materials, including filled and
reinforced compounds in addition to unfilled types; rigid and semi-rigid thermoplastics sheets
and films;
— rigid and semi-rigid thermosetting moulding materials, including filled and reinforced compounds;
rigid and semi-rigid thermosetting sheets, including laminates;
— fibre-reinforced thermosets and thermoplastic composites incorporating unidirectional or non-
unidirectional reinforcements, such as mat, woven fabrics, woven rovings, chopped strands,
combination and hybrid reinforcement, rovings and milled fibres; sheet made from pre-impregnated
materials (prepregs);
— thermotropic liquid crystal polymers.
The methods are not normally suitable for use with rigid cellular materials, for which ISO 1926 is used,
or for sandwich structures containing cellular materials.
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 2602, Statistical interpretation of test results — Estimation of the mean — Confidence interval
ISO 7500-1, Metallic materials — Calibration and verification of static uniaxial testing machines — Part 1:
Tension/compression testing machines — Calibration and verification of the force-measuring system
ISO 9513:2012, Metallic materials — Calibration of extensometer systems used in uniaxial testing
ISO 16012, Plastics — Determination of linear dimensions of test specimens
ISO 23529, Rubber — General procedures for preparing and conditioning test pieces for physical test methods
ISO 527-1:2019(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
gauge length
L
initial distance between the gauge marks on the central part of the test specimen
Note 1 to entry: It is expressed in millimetres (mm).
Note 2 to entry: The values of the gauge length that are indicated for the specimen types in the different parts of
ISO 527 represent the maximum relevant gauge length.
3.2
thickness
h
smaller initial dimension of the rectangular cross-section in the central part of a test specimen
Note 1 to entry: It is expressed in millimetres (mm).
3.3
width
b
larger initial dimension of the rectangular cross-section in the central part of a test specimen
Note 1 to entry: It is expressed in millimetres (mm).
3.4
cross-section
A
product of initial width (3.3) and thickness (3.2), A = bh, of a test specimen
Note 1 to entry: It is expressed in square millimetres, (mm ).
3.5
test speed
v
rate of separation of the gripping jaws
Note 1 to entry: It is expressed in millimetres per minute (mm/min).
3.6
stress
σ
normal force per unit area of the original cross-section (3.4) within the gauge length (3.1)
Note 1 to entry: It is expressed in megapascals (MPa).
Note 2 to entry: In order to differentiate from the true stress related to the actual cross-section of the specimen,
this stress is frequently called “engineering stress”.
2 © ISO 2019 – All rights reserved

ISO 527-1:2019(E)
3.6.1
stress at yield
σ
y
stress at the yield strain (3.7.1)
Note 1 to entry: It is expressed in megapascals (MPa).
Note 2 to entry: It may be less than the maximum attainable stress (see Figure 1, curve 2).
3.6.2
strength
σ
m
stress at the first local maximum observed during a tensile test
Note 1 to entry: It is expressed in megapascals (MPa).
Note 2 to entry: This may also be the stress at which the specimen yields or breaks (see Figure 1).
3.6.3
stress at x % strain
σ
x
stress at which the strain, ε, reaches the specified value x expressed as a percentage
Note 1 to entry: It is expressed in megapascals (MPa).
Note 2 to entry: Stress at x % strain may, for example, be useful if the stress/strain curve does not exhibit a yield
point (see Figure 1, curve 4).
3.6.4
stress at break
σ
b
stress at which the specimen breaks
Note 1 to entry: It is expressed in megapascals (MPa).
Note 2 to entry: It is the highest value of stress on the stress-strain curve directly prior to the separation of the
specimen, i.e directly prior to the load drop caused by crack initiation.
3.7
strain
ε
increase in length per unit original length of the gauge
Note 1 to entry: It is expressed as a dimensionless ratio, or as a percentage (%).
3.7.1
strain at yield
yield strain
ε
y
first occurrence in a tensile test of strain increase without a stress increase
Note 1 to entry: It is expressed as a dimensionless ratio, or as a percentage (%).
Note 2 to entry: See Figure 1, curves (2) and (3).
Note 3 to entry: See Annex A for computer-controlled determination of the yield strain.
ISO 527-1:2019(E)
3.7.2
strain at break
ε
b
strain at the last recorded data point before the stress (3.6) is reduced to less than or equal to 10 % of
the strength (3.6.2) if the break occurs prior to yielding
Note 1 to entry: It is expressed as a dimensionless ratio, or as a percentage (%).
Note 2 to entry: See Figure 1, curves (1) and (4).
3.7.3
strain at strength
ε
m
strain at which the strength (3.6.2) is reached
Note 1 to entry: It is expressed as a dimensionless ratio, or as a percentage (%).
3.8
nominal strain
ε
t
representation of strain (3.7) calculated from grip displacement and the gripping distance (3.11) by one
of the methods in 10.2.2
Note 1 to entry: It is expressed as a dimensionless ratio, or as a percentage (%).
Note 2 to entry: It may be calculated either based on the grip displacement from the beginning of the test or based
on the increase of grip displacement beyond the strain at yield, if the latter is determined with an extensometer
(preferred for multipurpose test specimens).
3.8.1
nominal strain at break
ε
tb
nominal strain at the last recorded data point before the stress (3.6) is reduced to less than or equal to
10 % of the strength (3.6.2) if the break occurs after yielding
Note 1 to entry: It is expressed as a dimensionless ratio, or as a percentage (%).
Note 2 to entry: See Figure 1, curves (2) and (3).
3.8.2
nominal strain at strength
ε
tm
nominal strain at which the strength (3.6.2) is reached
Note 1 to entry: It is expressed as a dimensionless ratio, or as a percentage (%).
Note 2 to entry: See Figure 1, curves (2), (3) and (4).
3.9
tensile modulus
modulus of elasticity under tension
E
t
slope of the stress/strain curve σ(ε) in the interval between the two strains ε = 0,05 % and ε = 0,25 %
1 2
Note 1 to entry: It is expressed in megapascals (MPa).
Note 2 to entry: It may be calculated either as the chord modulus or as the slope of a linear least-squares
regression line in this interval (see Figure 1, curve 4).
Note 3 to entry: This definition does not apply to films.
4 © ISO 2019 – All rights reserved

ISO 527-1:2019(E)
3.10
Poisson's ratio
µ
negative ratio of the strain change Δε , in one of the two axes normal to the direction of extension,
n
to the corresponding strain change Δε in the direction of extension, within the linear portion of the
l
longitudinal versus normal strain curve
Note 1 to entry: It is expressed as a dimensionless ratio.
Note 2 to entry: Since the lateral strain change Δε is a negative number and the longitudinal strain change Δε is
n l
positive, the Poissons ratio as defined in 3.10 is a positive number.
3.11
gripping distance
L
initial length of the part of the specimen between the grips
Note 1 to entry: It is expressed in millimetres (mm).
3.12
rigid plastic
plastic that has a modulus of elasticity in flexure (or, if that is not applicable, in tension) greater than
700 MPa under a given set of conditions
3.13
semi-rigid plastic
plastic that has a modulus of elasticity in flexure (or, if that is not applicable, in tension) between 70 MPa
and 700 MPa under a given set of conditions
ISO 527-1:2019(E)
Key
X strain and/or nominal strain
Y stress
1 Curve (1) represents a brittle material, breaking without yielding at low strains. Curve (4) represents a soft
rubberlike material breaking at larger strains (>50 %).
2, 3 Curves (2) and (3) represent materials that have a yield point with (2) or without (3) stress increase after
yielding. Curves (2) and (3) are curves “stress vs. strain” up to the yield point and “stress vs. nominal strain”
beyond the yield point.
4 Curve (4) may be either stress vs. strain or stress vs. nominal strain depending on equipment used.
Figure 1 — Typical stress/strain curves
4 Principle and methods
4.1 Principle
The test specimen is extended along its major longitudinal axis at a constant test speed until the
specimen fractures or until the stress (load) or the strain (elongation) reaches some predetermined
value. During this procedure, the load sustained by the specimen and the elongation are measured.
4.2 Method
4.2.1 The methods are applied using specimens which may be either moulded to the chosen dimensions
or machined, cut or punched from finished and semi-finished products, such as mouldings, laminates,
films and extruded or cast sheet. The types of test specimen and their preparation are described in the
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ISO 527-1:2019(E)
relevant part of ISO 527 typical for the material. In some cases, a multipurpose test specimen may be
used. Multipurpose and miniaturized test specimens are described in ISO 20753.
4.2.2 The methods specify preferred dimensions for the test specimens. Tests which are carried out
on specimens of different dimensions, or on specimens which are prepared under different conditions,
may produce results which are not comparable. Other factors, such as the speed of testing and the
conditioning of the specimens, can also influence the results. Consequently, when comparative data are
required, these factors shall be carefully controlled and recorded.
5 Apparatus
5.1 Testing machine
5.1.1 General
The machine shall comply with ISO 7500-1 and ISO 9513, and meet the specifications given in 5.1.2
to 5.1.6.
5.1.2 Test speeds
The tensile-testing machine shall be capable of maintaining the test speeds chosen within the tolerances
specified in Table 1.
Table 1 — Recommended test speeds
Test speed Tolerance
v %
mm/min
0,125
0,25
0,5
1 ±20
±10
5.1.3 Grips
Grips for holding the test specimen shall be attached to the machine so that the major axis of the test
specimen coincides with the direction of extension through the centre line of the grip assembly. The
test specimen shall be held such that slip relative to the gripping jaws is prevented. The gripping system
shall not cause premature fracture at the jaws or squashing of the specimen in the grips.
ISO 527-1:2019(E)
For the determination of the tensile modulus, it is essential that the strain rate is constant and does not
change, for example, due to motion in the grips. This is important especially if wedge action grips are used.
NOTE For the prestress, which can be necessary to obtain correct alignment (see 9.3) and specimen seating
and to avoid a toe region at the start of the stress/strain diagram, see 9.4.
5.1.4 Force indicator
The force measurement system shall comply with class 1 as defined in ISO 7500-1.
5.1.5 Strain indicator
5.1.5.1 Extensometers
Contact extensometers shall comply with ISO 9513, class 1. The accuracy of this class shall be attained
in the strain range over which measurements are being made. Non-contact extensometers may also be
used, provided they meet the same accuracy requirements.
The extensometer shall be capable of determining the change in the gauge length of the test specimen at
any time during the test. It is desirable, but not essential, that the instrument should record this change
automatically. The instrument shall be essentially free of inertia lag at the specified speed of testing.
For the determination of tensile modulus, the instrument shall be capable of measuring the change in
the gauge length of the specimen with an accuracy of 1 % of the relevant value or better for all gauge
lengths of 50 mm or higher, corresponding to a requirement of absolute accuracy of ±1 μm for a gauge
length of 50 mm and to ±1,5 μm, in case a gauge length of 75 mm is used.
For smaller gauge lengths between 20 mm and 50 mm an absolute accuracy of ±1 μm is sufficient (see
Figure 2 and Annex C.)
NOTE Depending on the gauge length used, the accuracy requirement of 1 % translates to different absolute
accuracies for the determination of the elongation within the gauge length. The constant absolute accuracy for
the measurement of change in gauge length leads to relative accuracies of 2 % for gauge length 25 mm and of
2,5 % for gauge length 20 mm (see Figure 2).
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ISO 527-1:2019(E)
Figure 2 — Accuracy requirements for extensometers for tensile modulus determination at
different gauge lengths
Commonly used optical extensometers record the deformation taken at one broad test-specimen
surface: In the case of such a single-sided strain-testing method, ensure that low strains are not
falsified by bending, which may result from even faint misalignment and initial warpage of the test
specimen, and which generates strain differences between opposite surfaces of the test specimen. It
is recommended to use strain-measurement methods that average the strains of opposite sides of the
test specimen. This is relevant for tensile modulus determination, but less so for measurement of larger
strains.
5.1.5.2 Strain gauges
Specimens may also be instrumented with longitudinal strain gauges; the accuracy of which shall be
−6
1 % of the relevant value or better. This corresponds to a strain accuracy of 20 × 10 (20 microstrains)
for the measurement of the tensile modulus. The gauges, surface preparation and bonding agents should
be chosen to exhibit adequate performance on the subject material.
ISO 527-1:2019(E)
5.1.6 Recording of data
5.1.6.1 General
The data acquisition frequency needed for the recording of data (force, strain, elongation) shall be
sufficiently high in order to meet accuracy requirements.
5.1.6.2 Recording of strain data
The minimum data acquisition frequency f , needed for integral transmission from the sensor to the
min
indicator, can then be calculated as shown in Formula (1):
v L
f =× (1)
min
60 Lr⋅
where
f is the frequency, expressed in hertz (Hz);
min
v is the test speed, expressed in mm/min;
L / L is the ratio between the gauge length L and initial gripping distance L;
0 0
r is the minimum resolution, expressed in millimetre (mm), of the strain signal required to
obtain accurate data. Typically, it is half the accuracy value or better.
The recording frequency of the test machine shall be at least equal to this data rate f .
min
5.1.6.3 Recording of force data
The required recording rate depends on the test speed, the strain range, the accuracy and the initial
gripping distance. The tensile modulus, the test speed and the gripping distance determine the rise rate
of force. The ratio of rise rate of force to the accuracy needed determines the recording frequency. See
below for examples.
Rise rate of force is given by Formula (2):
EA⋅⋅v
t

F = (2)
60L
where

is the rise rate of force, expressed in newtons per second (N/s);
F
E is the tensile modulus, expressed in megapascals (MPa);
t
A is the cross-sectional area of the test specimen, expressed in square millimetres (mm );
v is the test speed, expressed in millimetres per minute (mm/min);
L is the gripping distance, expressed in millimetres (mm).
Using the force difference in the tensile modulus range to define accuracy requirement in the same way
as for the extensometer, Formulae (3) to (5) apply, assuming that the relevant force is to be determined
to within 1 %.
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ISO 527-1:2019(E)
Force difference in the tensile modulus determination range:
ΔΔFE=⋅AE⋅−()εε =⋅A⋅ ε (3)
tt21
Accuracy (half of 1 %):
−−33
rF=⋅5105⋅=ΔΔ⋅⋅10 EA⋅⋅ ε (4)
t
Recording frequency:

EA⋅⋅v
F
t
f == (5)
force
−3
r
EA⋅⋅Δε⋅⋅60 L⋅⋅510
t
−3
EXAMPLE With v = 1 mm/min, Δε = 2 × 10 and L = 115 mm, a recording frequency of f = 14,5 Hz is found.
force
5.2 Devices for measuring width and thickness of the test specimens
See ISO 16012 and ISO 23529, where applicable. Use measurement tips/knife edges of such size and
orientation as to allow the precise determination of the dimension in the desired location.
6 Test specimens
6.1 Shape and dimensions
See the part of ISO 527 relevant to the material being tested.
6.2 Preparation of specimens
See the part of ISO 527 relevant to the material being tested.
6.3 Gauge marks
See the appropriate part of ISO 527 for the relevant conditions of the gauge length.
If optical extensometers are used, especially for thin sheet and film, gauge marks on the specimen may
be necessary to define the gauge length. These shall be equidistant from the midpoint (±1 mm), and the
gauge length shall be measured to an accuracy of 1 % or better.
Gauge marks shall not be scratched, punched or impressed upon the test specimen in any way that may
damage the material being tested. It shall be ensured that the marking medium has no detrimental
effect on the material being tested and that, in the case of parallel lines, they are as narrow as possible.
Extension of the gauge marks due to stretching shall not influence the strain measurements.
6.4 Checking the test specimens
Ideally, the specimens should be free of twist and should have mutually perpendicular pairs of parallel
surfaces (see NOTE 1, NOTE 2 and Figure 3). The surfaces and edges shall be free from defects that may
influence the test results like scratches, pits, sink marks and flash. Draft angles of up to 2° and sink
marks with a thickness difference of Δh ≤ 0,1 mm are acceptable, as are purely optical effects that do
not affect the test result.
The specimens shall be checked for conformity with these requirements by visual observation against
straight-edges, squares or flat plates, or with micrometer callipers.
ISO 527-1:2019(E)
Specimens showing observed or measured departure from one or more of these requirements shall be
rejected. If non-conforming specimens are tested, report the reasons.
NOTE 1 Injection-moulded specimens typically have draft angles of 1° (in the gauge section) to 2° (at the
shoulders) to facilitate demoulding. Also, injection-moulded test specimens are never absolutely free of sink
marks. Due to differences in the cooling history, generally the thickness in the centre of the specimen is smaller
than at the edge.
NOTE 2 ISO 294-1:2017, Annex D gives guidance on how to reduce sink marks in injection-moulded test
specimens.
Key
1 width determination
2 thickness determination
3 smallest thickness, h
min
4 greatest thickness, h
max
5 micrometer tip
a
The edge of the micrometer tip shall have contact to the specimen within ± 0,5 mm from the centre.
b
The micrometer tip shall have contact to the specimen within ± 3,25 mm from the centre.
NOTE Δh = h – h ≤ 0,1 mm.
max min
Figure 3 — Cross-section of injection-moulded test specimen with sink marks and draft angle
(exaggerated) and micrometer tips
6.5 Anisotropy
See the part of ISO 527 relevant to the material being tested.
7 Number of test specimens
7.1 A minimum of five test specimens shall be tested for each of the required directions of testing. The
number of measurements may be more than five if greater precision of the mean value is required. It is
possible to evaluate this by means of the confidence interval (95 % probability, see ISO 2602).
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ISO 527-1:2019(E)
7.2 Dumb-bell specimens that break or slip inside the grips shall be discarded and further specimens
shall be tested.
8 Conditioning
The test specimen shall be conditioned as specified in the appropriate standard for the material
concerned. In the absence of this information, the most appropriate set of conditions from ISO 291 shall
be selected and the conditioning time is at least 16 h, unless otherwise agreed upon by the interested
parties, for example, for testing at elevated or low temperatures.
The preferred atmosphere is (23 ± 2) °C and (50 ± 10) % RH, except when the properties of the material
are known to be insensitive to moisture, in which case humidity control is unnecessary.
9 Procedure
9.1 Test atmosphere
Conduct the test in the same atmosphere used for conditioning the test specimen, unless otherwise
agreed upon by the interested parties, for example, for testing at elevated or low temperatures.
9.2 Dimensions of test specimen
9.2.1 Measure the width and the thickness of the test specimen (see 9.2.2), following the general
guidance of ISO 16012 or ISO 23529, as applicable, within the limits indicated in Figure 3, to the nearest
0,1 mm for the width and to the nearest 0,01 mm for the thickness.
Avoid measuring the thickness at the edge of the specimen and directly in the centre (see NOTE). With
rectangular or sharp tip faces the long side of the tip shall be parallel to the width direction when
measuring thickness, and parallel to the thickness direction when measuring width.
NOTE This excludes the maximum and minimum thickness, which for injection moulded test specimens
usually is found at the edge and in the centre, respectively. Injection moulded test specimens prepared according
ISO 294-1, will generally have thickness differences due to sink marks of Δh = h – h ≤ 0,1 mm (see Figure 3).
max min
For injection-moulded test specimens, it is sufficient to determine the width and thickness within 5 mm
midway between the shoulders.
9.2.2 In the case of injection-moulded specimens, obtained from multiple-cavity moulds, ensure that
the dimensions of the specimens do not differ by more than ±0,25 % between cavities.
For test specimens cut from sheet or film material, it is permissible to assume that the mean width
of the central parallel portion of the die is equivalent to the corresponding width of the specimen.
The adoption of such a procedure should be based on comparative measurements taken at periodic
intervals.
For the purposes of this document, the test specimen dimensions used for calculating tensile properties
are measured at ambient temperature only. For the measurement of properties at other temperatures,
therefore, the effects of thermal expansion are not taken into account.
9.3 Gripping
Place the test specimen in the grips, taking care to align the longitudinal axis of the test specimen with
the axis of the testing machine. Tighten the grips evenly and firmly to avoid slippage of the test specimen
and movement of the grips during the test. Gripping pressure shall not cause fracture or squashing of
the test specimen (see NOTE 2).
NOTE 1 Stops can be used to facilitate alignment of the test specimen, especially in manual operation.
ISO 527-1:2019(E)
For gripping test specimens within a temperature chamber, it is recommended to close initially only
one grip and to tighten the second one only after the temperature of the test specimen is equilibrated,
unless the machine is capable of continuously reducing thermal stress if it arises.
NOTE 2 Fracture in the grips can happen, for example, when testing of specimens after heat aging. Squashing
can occur in tests at elevated temperatures.
9.4 Pr
...