ISO/FDIS 148-4

FINAL DRAFT
International
Standard
ISO/TC 164/SC 4
Metallic materials — Charpy
Secretariat: ANSI
pendulum impact test —
Voting begins on:
2026-01-05
Part 4:
Testing of miniature Charpy-type
Voting terminates on:
2026-03-02
V-notch test pieces
Matériaux métalliques — Essai de flexion par choc sur éprouvette
Charpy —
Partie 4: Essai des éprouvettes type Charpy miniaturisées à
entaille en V
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
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Reference number
FINAL DRAFT
International
Standard
ISO/TC 164/SC 4
Metallic materials — Charpy
Secretariat: ANSI
pendulum impact test —
Voting begins on:
Part 4: 2026-01-09
Testing of miniature Charpy-type
Voting terminates on:
V-notch test pieces
Matériaux métalliques — Essai de flexion par choc sur éprouvette
Charpy —
Partie 4: Essai des éprouvettes type Charpy miniaturisées à
entaille en V
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.
© ISO 2026
IN ADDITION TO THEIR EVALUATION AS
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BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
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ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle of the test . 1
5 Test pieces . 2
5.1 General .2
5.2 Notch geometry .2
5.3 Tolerance of the test pieces .2
5.4 Preparation of the test pieces .2
5.5 Marking of the test pieces .2
6 Test equipment . 3
6.1 General .3
6.2 Installation and verification .3
6.3 Striker .3
7 Test procedure . 3
7.1 General .3
7.2 Test temperature and test piece transfer .3
7.3 Incomplete fracture .3
8 Test report . 4
[2]
Annex A (informative) Alternative Charpy-type V-notch miniature test pieces . 7
Bibliography . 8

iii
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
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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
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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)
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This document was prepared by Technical Committee ISO TC 164, Mechanical testing of metals, Subcommittee
SC 4, Fatigue, fracture and toughness testing.
A list of all parts in the ISO 148 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
FINAL DRAFT International Standard ISO/FDIS 148-4:2026(en)
Metallic materials — Charpy pendulum impact test —
Part 4:
Testing of miniature Charpy-type V-notch test pieces
1 Scope
This document specifies the pendulum impact test method on miniature Charpy-type V-notch test pieces of
metallic materials. This document does not cover instrumented impact testing of miniature Charpy V-notch
[1]
test pieces, which is specified in ISO 14556:2023, Annex D .
This document can be applied, by agreement, to other impact testing machines, such as drop-weight towers
or high-speed servo-hydraulic machines.
The user should be aware that data obtained from miniature test pieces are not directly comparable to those
[2,3]
obtained from full-size standard Charpy V-notch test pieces .
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 148-1, Metallic materials — Charpy pendulum impact test — Part 1: Test method
ISO 148-2, Metallic materials — Charpy pendulum impact test — Part 2: Verification of testing machines
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 148-1 and the following 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 https:// www .electropedia .org/
3.1
miniature Charpy-type V-notch test piece
Charpy-type V-notch test piece in which all linear dimensions (width W, thickness B, length L, ligament
width) are smaller than for a standard Charpy V-notch test piece
Note 1 to entry: Standard Charpy V-notch test pieces are covered by ISO 148-1.
Note 2 to entry: Miniature Charpy-type V-notch test pieces should not be confused with sub-size Charpy V-notch test
pieces, in which one or more linear dimensions, but not all, are smaller than for a standard test piece, for example, test
pieces with thickness B = 5 mm, width W = 10 mm, lengt
...