EN ISO 13802:2025

SLOVENSKI STANDARD
01-november-2025
Polimerni materiali - Preverjanje strojev z nihalom za ugotavljanje udarnih
lastnosti - Preskušanje z udarnim preskusom Charpy, Izod in natezno-udarno
preskušanje (ISO 13802:2025)
Plastics - Verification of pendulum impact-testing machines - Charpy, Izod and tensile
impact-testing (ISO 13802:2025)
Kunststoffe - Verifizierung von Pendelschlagwerken - Charpy-, Izod- und
Schlagzugversuch (ISO 13802:2025)
Plastiques - Vérification des machines d'essai de choc pendulaire - Essais de choc
Charpy, Izod et de choc-traction (ISO 13802:2025)
Ta slovenski standard je istoveten z: EN ISO 13802:2025
ICS:
83.200 Oprema za gumarsko Equipment for the rubber and
industrijo in industrijo plastics industries
polimernih materialov
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 13802
EUROPEAN STANDARD
NORME EUROPÉENNE
August 2025
EUROPÄISCHE NORM
ICS 83.200 Supersedes EN ISO 13802:2015
English Version
Plastics - Verification of pendulum impact-testing
machines - Charpy, Izod and tensile impact-testing (ISO
13802:2025)
Plastiques - Vérification des machines d'essai de choc Kunststoffe - Verifizierung von Pendelschlagwerken -
pendulaire - Essais de choc Charpy, Izod et de choc- Charpy-, Izod- und Schlagzugversuch (ISO
traction (ISO 13802:2025) 13802:2025)
This European Standard was approved by CEN on 23 August 2025.

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, Türkiye 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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 13802:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 13802:2025) 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 SIS.
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 February 2026, and conflicting national standards
shall be withdrawn at the latest by February 2026.
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 13802:2015.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
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, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 13802:2025 has been approved by CEN as EN ISO 13802:2025 without any modification.

International
Standard
ISO 13802
Third edition
Plastics — Verification of pendulum
2025-08
impact-testing machines — Charpy,
Izod and tensile impact-testing
Plastiques — Vérification des machines d'essai de choc pendulaire
— Essais de choc Charpy, Izod et de choc-traction
Reference number
ISO 13802:2025(en) © ISO 2025
ISO 13802:2025(en)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 13802:2025(en)
Contents  Page
Foreword .iv
Introduction .v
1  Scope . 1
2  Normative references . 1
3  Terms and definitions . 1
4  Measurement instruments . 3
5  Description of a pendulum impact-testing machine. 4
5.1 Types of pendulum impact-testing machines.4
5.2 Pendulum impact testing machine components.4
6  Procedure for verification and inspection of a pendulum impact-testing machine . 5
6.1 Machine design and manufacturer .5
6.2 Machine frame field verification.5
6.2.1 General .5
6.2.2 Installation .5
6.2.3 Levelness .6
6.2.4 Axial play of the pendulum bearings.6
6.2.5 Radial play of the pendulum bearings .6
6.2.6 Mechanism for holding and releasing the pendulum.6
6.2.7 Free hanging position .6
6.2.8 Contact between specimen and striking edge (Izod/Charpy) .6
6.2.9 Potential energy, E .6
6.2.10 Pendulum length, L .7
P
6.2.11 Impact length, L .8
Ι
6.2.12 Velocity of the pendulum at instant of impact, v .8
Ι
6.3 Charpy testing machines .9
6.4 Izod testing machines .10
6.5 Tensile impact testing machines .11
6.6 Energy indicating system . 12
6.6.1 Types of scale . 12
6.6.2 Verification of analogue indicating equipment . 12
6.6.3 Error in the indicated absorbed energy, W on analogue indicating systems . 12
i,
6.6.4 Verification of digital indicating equipment . 13
6.7 Losses due to friction . . 13
6.7.1 Types of loss . . 13
6.7.2 Determination of the loss due to friction in the pointer . 13
6.7.3 Determination of losses due to air resistance and friction in the pendulum
bearings .14
6.7.4 Calculation of the total energy lost due to friction .14
6.7.5 Maximum permissible losses due to friction .14
7  Frequency of verification . 16
8  Verification report .16
Annex A (normative)  Design requirements for Charpy machines . 17
Annex B (normative)  Design requirements for Izod machines .20
Annex C (normative)  Design requirements for tensile impact machines .23
Annex D (informative)  Ratio of frame mass to pendulum mass .28
Annex E (informative)  Deceleration of pendulum during impact .31
Annex F (informative)  Gauge plate for verification of Charpy impact pendulums .33

iii
ISO 13802:2025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 2, Mechanical
properties, 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 13802:2015), which has been technically
revised.
The main changes are as follows:
— removed term entries 3.6 (gravity length), 3.7 (gyration length), and 3.19 (half-height Charpy impact
reference specimen) and renumbered Clause 3 accordingly;
— corrected the measurement unit and the requirement in 6.2.4;
— updated acceptance criteria in 6.6.3;
— updated the references in Note 2 of the Clause 7;
— corrected value D in Table A.1 to align with the value indicated in Table 4;
— corrected value p in Table B.1 to align with the value indicated in Table 4;
— corrected the Formulae (D.4) and (D.5) in Annex D.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
ISO 13802:2025(en)
Introduction
A pendulum impact-testing machine verified in accordance with this document, and assessed as satisfactory,
is considered suitable for impact testing with unnotched and notched test specimens of different types.
The verification of some geometrical properties is difficult to perform on the assembled instrument.
It is, therefore, assumed that the manufacturer is responsible for the verification of such properties and
for providing reference planes on the instrument that enable proper verification in accordance with this
document.
v
International Standard ISO 13802:2025(en)
Plastics — Verification of pendulum impact-testing machines
— Charpy, Izod and tensile impact-testing
1  Scope
This document specifies frequency and methods for the verification of pendulum impact-testing machines
used for the Charpy impact test, Izod impact test, and tensile impact test described in ISO 179-1, ISO 180 and
ISO 8256, respectively. Verification of instrumented impact machines is covered insofar as the geometrical
and physical properties of instrumented machines are identical to non-instrumented machines. The force/
work verification of instrumented machines is not covered in this document.
This document is applicable to pendulum-type impact-testing machines, of different capacities and/or
designs, with the geometrical and physical properties specified in Clause 5.
Methods are specified for verification of the geometrical and physical properties of the different parts of the
test machine.
These methods are for use when the machine is being installed, has been repaired, has been moved, or is
undergoing periodic checking.
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 179-1, Plastics — Determination of Charpy impact properties — Part 1: Non-instrumented impact test
ISO 179-2, Plastics — Determination of Charpy impact properties — Part 2: Instrumented impact test
ISO 180, Plastics — Determination of Izod impact strength
ISO 8256:2023, Plastics — Determination of tensile-impact strength
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/
3.1
verification
proof, with the use of calibrated standards or standard reference materials, that the calibration (3.2) of an
instrument is acceptable
3.2
calibration
set of operations that establish, under specified conditions, the relationship between values indicated by a
measuring instrument or measuring system and values corresponding to appropriate standards or known
values derived from standards
ISO 13802:2025(en)
3.3
period of oscillation of the pendulum
Τ
P
period of a single complete oscillation of the pendulum, oscillating at angles of oscillation of less than 5°, on
average, to each side of the vertical
Note 1 to entry: It is expressed in seconds (s).
3.4
centre of percussion
point on a pendulum at which a perpendicular impact in the plane of swing does not cause reaction forces at
the axis of rotation of the pendulum
3.5
pendulum length
L
P
distance between the axis of rotation of the pendulum and the centre of percussion (3.4) and it is the distance
from the axis of rotation where the mass of a pendulum would have to be concentrated to have the same
period of swing, Τ , as the actual pendulum
P
Note 1 to entry: It is expressed in metres (m).
3.6
impact length
L
Ι
distance between the axis of the rotation of the pendulum and the point of impact of the striking edge at the
centre of the specimen face
Note 1 to entry: It is expressed in metres (m).
3.7
release angle
α
angle relative to the vertical, from which the pendulum is released
Note 1 to entry: Usually, the test specimen is impacted at the lowest point of the pendulum swing (α = 0°). In this case,
the release angle will also be the angle of fall [see Figure 1b)].
Note 2 to entry: It is expressed in degrees (°).
3.8
impact velocity
v
Ι
velocity of the pendulum at the moment of impact
Note 1 to entry: It is expressed in metres per second (m/s).
3.9
potential energy
E
energy of the pendulum in its starting position, relative to its position at impact
Note 1 to entry: It is expressed in Joules (J).
3.10
impact energy
W
energy required to deform, break, and push away the test specimen
Note 1 to entry: It is expressed in Joules (J).

ISO 13802:2025(en)
3.11
frame
part of the machine carrying the pendulum bearings, the supports, the vice and/or clamps, the measurement
instruments, and the mechanism for holding and releasing the pendulum
Note 1 to entry: The mass of the frame, m , is expressed in kilograms (kg).
F
3.12
base
part of the framework of the machine located below the horizontal plane of the supports
3.13
anvil
portion of the machine that serves to properly position the test piece for impact, with respect to the striker
and the test piece supports, and supports the test piece under the force of the strike
3.14
test specimen support
portion of the machine that serves to properly position the test specimen for impact, with respect to the
centre of percussion of the pendulum, the striker and the anvils (3.13)
3.15
striker
portion of the pendulum that contacts the test piece
3.16
period of oscillation of the frame
T
F
period of the freely decaying, horizontal oscillation of the frame and which characterizes the oscillation of
the frame vibrating against the stiffness of the (resilient) mounting
Note 1 to entry: Examples of the mounting are test bench and/or its foundation (which may include damping material
for instance). See Annex D.
Note 2 to entry: It is expressed in seconds (s).
3.17
mass of the pendulum
m
P,max
mass of the heaviest pendulum used
Note 1 to entry: It is expressed in kilograms (kg).
3.18
Izod/Charpy impact reference specimen
specimen made from stainless steel 80 mm ± 0,05 mm in length and of rectangular section, 10 mm ± 0,02 mm
in height, and 10 mm ± 0,02 mm in width
3.19
tensile impact reference specimen
specimen made from stainless steel 80 mm ± 0,05 mm in length and of rectangular section, 10 mm ± 0,02 mm
in height, and 4 mm ± 0,02 mm in width
4  Measurement instruments
The verification methods specified in this document call for the use of straight edges, vernier calipers,
set squares, levels and dynamometers, load cells or scales, and timing devices to check if the geometrical
and physical properties of the components of the test machine conform to the requirements given in this
document.
ISO 13802:2025(en)
These measurement instruments shall be accurate enough to measure the parameters within the tolerance
limits given in Clause 6 (see Table 4).
5  Description of a pendulum impact-testing machine
5.1  Types of pendulum impact-testing machines
Three different types of test machines are covered in this document.
The construction and performance of a machine configured for Charpy testing shall be in accordance with
Annex A. Figure A.1 shows a typical example of a Charpy test machine. Important values to be verified are
listed in Table A.1. Test conditions shall be in accordance with the ISO 179 series.
The construction and performance of a machine configured for Izod testing shall be in accordance with
Annex B. Figure B.1 shows a typical example of an Izod test machine. Important values to be verified are
listed in Table B.1. Test conditions shall be in accordance with ISO 180.
The construction and performance of a machine configured for tensile impact testing shall be in accordance
with Annex C. Figure C.1 and Figure C.2 show typical examples of tensile impact-testing machines. Important
values to be verified are listed in Table C.1. Test conditions shall be in accordance with ISO 8256.
5.2  Pendulum impact testing machine components
5.2.1  Machine frame. The base of the machine and the structure supporting the pendulum.
5.2.1.1  Bearings.
5.2.1.2  Mechanism for holding and releasing the pendulum.
5.2.1.3  Base.
5.2.2  Pendulum.
5.2.2.1  Pendulum rod or compound (bifurcated) design.
5.2.2.2  Striker, with striking edge for Charpy or Izod impact tests or with striking surfaces or clamps for
tensile impact testing, according to ISO 8256, test methods A and B, respectively (see Figures C.1 and C.2 in
Annex C).
5.2.2.3  Add-on weights (optional), for increasing potential energy capacity of pendulum. There are
several pendulum designs available, and they are acceptable if they meet the requirements of this document.
5.2.3  Test specimen anvils, supports, clamps and/or holders.
5.2.3.1  Anvils and test specimen supports, for Charpy impact testing.
The Charpy test supports and anvils shall be located one on each side of the plane of swing of the pendulum.
The anvils shall be installed perpendicular to the supports and normal to the plane of swing of the pendulum.
Essentially, the specimen rests on the supports and the anvil takes the reaction from the impact on the
specimen. Recesses in the supports to accommodate flash on specimens are permitted.
5.2.3.2  Vice, for Izod impact testing.
5.2.3.3  Clamps or stops, for tensile impact testing (depending on ISO 8256, methods A and B).

ISO 13802:2025(en)
NOTE See Annex C.
5.2.3.4  Crossheads, for tensile impact testing (depending on ISO 8256, methods A and B).
NOTE See Annex C.
5.2.4  Indicating equipment for absorbed energy (e.g. scale and friction pointer or electronic readout
device).
6  Procedure for verification and inspection of a pendulum impact-testing machine
6.1  Machine design and manufacturer
There are several aspects of the design and manufacture of an impact machine that are critical to its
performance and can only be verified and documented at the time of manufacture by the manufacturer,
including the following (see Table 1);
a) centre of percussion;
b) axis of rotation;
c) pendulum plane of swing;
d) mass of frame.
Unless the ratio, m /m , of the mass of the frame to the mass of the heaviest pendulum used is at least 40,
F P,max
the frame shall be bolted to a rigid test bench.
Since many machines might not have been supplied with manufacturer’s verifications detailing the ratio of
the mass of the frame to the mass of the pendulum, bolting the machine to the test bench and levelling with
shims is strongly recommended.
Table 1 — Components of impact machine to be verified and documented only at the time of
manufacture
Parameter Unit Value
Centre of percussion mm At the centre of strike ±2,5
a
Axis of rotation of pendulum — Parallel within ±2/1 000 relative to the reference plane
Plane of swing relative to axis of rotation — 90° ± 0,1° to the axis of rotation
Mass of frame kg At least 40 times the weight of the heaviest pendulum
used or bolted to a heavy secure bench
a
The reference plane of a particular machine will vary depending on the manufacturer.
6.2  Machine frame field verification
6.2.1  General
Field verification of the machine frame shall consist of determining the items given in 6.2.2 to 6.2.12 (see
Table 4).
6.2.2  Installation
The pendulum impact-testing machine shall be installed on a sturdy bench or table in an area that is
free from vibration. If the machine is equipped with levelling adjustment screws, the adjustment screws
shall be fixed after levelling in order to maintain the frame in position and the stiffness of the mounting.
During an impact test, there shall be no visible displacement of the frame on its support. Verify that there
is no movement of either the machine or the test bench by configuring the machine with the highest energy

ISO 13802:2025(en)
capacity pendulum available on the machine. Latch the pendulum and place a level on the base. Release the
pendulum and observe the level for any movement of the bubble. Any bubble movement observed requires
that the machine be mounted in a more secure manner.
6.2.3  Levelness
Determine the levelness of the reference plane in the direction of the swing and perpendicular to the swing.
The machine shall be installed so that the reference plane is horizontal to within 2/1 000.
6.2.4  Axial play of the pendulum bearings
The endplay in the bearings of the pendulum spindle in the axial direction shall not exceed 0,25 mm.
6.2.5  Radial play of the pendulum bearings
Determine the radial play of the shaft in the pendulum bearings when a torque of 2 Nm ± 0,2 Nm is applied
in alternate directions perpendicular to the plane of swing of the pendulum. The total play in the radial
direction shall not exceed 0,05 mm.
6.2.6  Mechanism for holding and releasing the pendulum
The mechanism for releasing the pendulum from its initial position shall be visually inspected. A properly
functioning release mechanism operates freely and permits the release of the pendulum without initial
impulse, retardation or side vibration, or any other interference that would result in energy loss.
6.2.7  Free hanging position
When hanging free, the pendulum shall hang so that the striking edge is within 6,35 mm of the position
where it would just touch the reference specimen.
6.2.8  Contact between specimen and striking edge (Izod/Charpy)
For Izod and Charpy machines, the striker shall make contact over the full width of the Izod/Charpy impact
reference specimen.
One method of verifying this is as follows.
An Izod/Charpy impact reference specimen is tightly wrapped in thin paper (e.g. by means of adhesive tape),
and is placed in the specimen supports or clamp. Similarly, the striker edge is tightly wrapped in carbon
paper with the carbon side outermost (i.e. not facing the striker). From its position of equilibrium, the
pendulum is raised a few degrees, released so that it contacts the Izod/Charpy impact reference specimen,
and prevented from contacting the test piece a second time. The mark made by the carbon paper on the
paper covering the Izod/Charpy impact reference specimen should extend completely across the paper. This
test may be performed concurrently with that of checking the angle of contact between the striker and the
Izod/Charpy impact reference specimen.
6.2.9  Potential energy, E
Table 2 shows the nominal potential energy values of pendulums typically used in Charpy, Izod and tensile
impact machines. The potential energy, E, shall not differ by more than 1 % of the nominal value given in
Table 2. It shall be determined as follows.
a) Support the pendulum at an arbitrary length, L , from the axis of rotation, on a balance or dynamometer.
H
Ensure that the line from the axis of rotation to the centre of gravity of the pendulum is horizontal [see
Figure 1 a)].
b) Measure the vertical force, F , in newtons, at L and the length, L , in metres, to a precision of ±1,0 %.
H H H
ISO 13802:2025(en)
c) Calculate the horizontal moment, M , of the pendulum about the axis of rotation, in newton metres,
H
using Formula (1):
M = F L (1)
H H H
d) Measure the release angle, α [see Figure 1 b)], to a precision Δα , which corresponds to a relative
0 0
precision of 1/400th of the potential energy, E, and, if applicable, the impact angle, α , to within 0,25°.
I
Thus, for starting angles of 140°, 150°, and 160°, Δα is 0,39°, 0,54°, and 0,81°, respectively.
e) Calculate the potential energy, E, of the pendulum using Formula (2):
EM=−(cosααcos) (2)
HI 0
where
E is the potential energy of the pendulum, in joules;
M is the horizontal moment of the pendulum [see Formula (2)], in newton metres;
H
α is the release angle, in degrees;
α is the impact angle, in degrees.
Ι
NOTE 1 Most pendulum impact-testing machines use an impact angle of 0°, for which cos α = 1.
Ι
NOTE 2 In certain cases, it can be necessary to remove the pendulum from the machine to determine its moment,
M , by the method described.
H
Table 2 — Basic characteristics of Charpy, tensile and Izod impact-testing machines
Nominal potential  Type of test Impact velocity Maximum permissible loss-
energy es due to friction without
test specimen
E v % of E
Ι
J m/s
0,5 Charpy 4
1,0 Charpy 2
2,0 Charpy/Tensile 2,9 (±10 %) 1
4,0 Charpy/Tensile 0,5
5,0 Charpy 0,5
7,5 Charpy/Tensile
15 Charpy/Tensile
3,8 (±10 %) 0,5
25 Charpy/Tensile
50 Charpy/Tensile
1,0 Izod 2
2,75 Izod 1
5,5 Izod 3,5 (±10 %) 0,5
11 Izod 0,5
22 Izod 0,5
NOTE See Annex E for additional information about potential energy and impact velocity.
6.2.10 Pendulum length, L
P
The pendulum length, L shall be verified and documented by the manufacturer at the time of manufacture.
P,
Under normal conditions, it should not change but it shall be verified, if repaired or replaced, as part of the
calibration procedure. The pendulum length shall be determined for each available pendulum.
Determine the pendulum length to within the precision specified (see Table 3).

ISO 13802:2025(en)
The pendulum length is verified by measuring the period of oscillation (time of swing), T , of the pendulum.
P
Raise the pendulum and release from a height that results in a swing of a maximum of 5°, on average, and
measuring the time of a complete swing in seconds. Determine the period of oscillation as the mean value of
four determinations.
Table 3 — Examples of minimum number of oscillations for determination of T
P
L T Accuracy of time Minimum number
P P
measurement of oscillations
m s s n
0,225 0,95 0,1 50
0,01 10
0,390 1,25 0,1 50
0,01 10
NOTE Hand-held stopwatches are generally considered to have an accuracy of 0,1 s. Integrated electronic timing
devices are required to give greater accuracy of time measurement.
Determine the pendulum length, L , from the period of oscillation, T , of the pendulum using Formula (3):
P P
gT
P
L = (3)
P
4π
where
T is the period of oscillation of the pendulum, in seconds;
P
g is taken as equal to 9,81 m/s , however, if the local acceleration of gravity is known or is believed
to be significantly different from 9,81 m/s , the local acceleration of gravity shall be used;
π is taken as equal to 9,87.
Therefore, in metres, L = 0,248 5 T .
P P
The value of T shall be determined to a precision of 0,5 %.
P
6.2.11 Impact length, L
Ι
The impact length, L , shall be within 1 % of the pendulum length, L , as determined from the period of
Ι P
oscillation, T , of the pendulum [see Formula (3) and Figure 1 a)].
P
6.2.12 Velocity of the pendulum at instant of impact, v
Ι
The impact velocity, v , shall have the value given in Table 2 for Charpy, Izod, and tensile impact testing,
Ι
respectively.
Determine the impact velocity using Formula (4):
vg=−2 L (cosααcos) (4)
II I 0
where
v is the impact velocity, in metres per second;
Ι
g may be taken as 9,81 m/s (to save measurement at the site of each testing machine);
L is the impact length, in metres;
Ι
α is the release angle, in degrees;
α is the impact angle, in degrees.
Ι
NOTE In most cases, the impact angle is 0°, i.e. cos α = 1.
Ι
ISO 13802:2025(en)
a) Quantities for determining the horizontal moment
b) Quantities for scale calibration and potential energy calculations
Key
1 axis of rotation
2 vertical force, F
H
3 centre of percussion
4 angle of rise, α
R
5 release angle, α
6 arbitrary length from the axis of rotation, that the pendulum is supported on a balance or dynamometer, LH
Figure 1 — Quantities necessary for energy verification
6.3  Charpy testing machines
Inspection and verification of Charpy machines (see Figure A.1 and Table A.1) shall consist of the following.
a) Position of anvils, relative to striking edge.
The clearance between the anvils and the striker, or any adjacent part of the pendulum that pass
between the anvils, should be sufficient to ensure that the broken specimen is free to leave the machine
with the minimum of interference, thus, preventing the possibility of the specimen rebounding into
the pendulum. Any end stop used for locating the test specimen in the anvils should not impede the
movement of the specimen during the test.

ISO 13802:2025(en)
b) Contact between Charpy striker and specimen.
c) Angle between the line of contact of the striker and the horizontal axis of the Izod/Charpy impact
reference specimen (see Figure A.1).
d) Angle of striker,θ .
e) Radius of striking edge,R .
f) Parallelism (Orientation) of supports, p .
g) Radius of anvils, R .
h) Angle of taper of anvils, θ .
i) Angle of slope of anvils, θ .
j) Angle between supports and anvils surfaces, θ .
k) Span between the supports.
NOTE 1 The span between the supports varies with specimen type.
l) Location of notch.
If means is provided for locating the test specimen, it shall ensure that the plane of symmetry of the notch
lies within ±0,5 mm of the centre of the gap between the specimen anvils.
NOTE 2 One type of a gauge that can be used to check the distance between the anvils and their alignment relative
to the striking edge is shown in Annex F.
6.4  Izod testing machines
Inspection and verification of Izod machines (see Figure B.1 and Table B.1) shall consist of the following.
a) Line of contact of the striker
b) Striking edge of pendulum for Izod test machines. The striker or tup shall conform to all of the
requirements listed below.
1) Radius,R . The striking edge of the striker or tup shall have a cylindrical surface with its axis
horizontal and perpendicular to the plane of motion of the pendulum.
2) Angle relative to the longitudinal axis of the Izod/Charpy impact reference specimen, θ . When it
contacts the Izod/Charpy impact reference specimen, the striking edge, which shall be centred and
extended beyond both sides of the Izod/Charpy reference specimen.
3) Parallelism,p , with face of Izod/Charpy impact reference specimen (over full width).
c) Specimen vice. Vice (clamping and support blocks) designed to hold the test specimen in Izod machines
(see Figure B.1) shall conform to all of the requirements listed below.
1) Parallelism of vice faces in horizontal and vertical direction. With an Izod/Charpy impact reference
specimen clamped in place, the vice faces shall be parallel in both the horizontal and the vertical
direction, p .
2) Horizontality of the top surface of the vice, relative to reference plane, p .
3) Angle between the faces of the support block/clamping block and top surface of vice, θ .
Use a straight edge and a hand-held light to check for wear. Any indication of light between the straight
edge and the support block indicates that the support block is worn and that it needs to be replaced.
4) Radius of support block. Verify the top edge of the support, about which bending takes place, R .
ISO 13802:2025(en)
5) Location of striking edge above top surface of support, D .
d) Location of specimen and striker
When a reference specimen is located in the vice and clamped so that it is attached rigidly to the frame,
the following requirements shall be conformed to:
1) top surface of the support block shall be parallel, to within 3/1 000, to the reference plane of the
machine;
2) longitudinal axis of the specimen shall be perpendicular, to within ±0,5°, to the top surface of the
support block;
3) notch, which shall face the striker, shall be perpendicular to the plane of swing of the pendulum,
and the plane of symmetry of the notch shall coincide with the top surface of the support block, both
within ±0,1 mm;
4) when it contacts the specimen, the striking edge, which shall be sufficiently wide to extend beyond
both sides of the specimen, shall be perpendicular, to within ±2°, to the longitudinal axis of the
specimen and parallel, to within 0,025 mm (= 0,36°), to the face of the specimen, over the full width of
the specimen.
With a specimen clamped in place, the vice faces shall be parallel, to within 4/1 000, in both the horizontal
and the vertical direction.
6.5  Tensile impact testing machines
Inspection and verification of tensile impact machines (see Figure C.1 and Figure C.2 and Table C.1) shall
consist of the following.
a) Specimen clamps for tensile impact test machines shall be conformed to the following
1) Method A
The specimen clamps surfaces shall be coplanar.
The specimen clamps shall be parallel to the axis of rotation of the pendulum.
When using a tensile impact reference specimen, the centres of the contact areas on the crossheads and
on the striker shall lie in a plane which is horizontal to within 2° and within ±0,5 mm of the plane of
swing of the pendulum.
2) Method B
When clamped in place, tensile impact reference specimen shall lie in the plane of swing of the pendulum
to within ±0,5 mm and in such a way that its longitudinal axis is parallel, to within 4/1 000, to the plane
of swing of the pendulum.
The contact surfaces on the crosshead, mounted on a rectangular reference specimen, sh
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