EN ISO 7720:2025

SLOVENSKI STANDARD
01-september-2025
Vezni elementi - Šestrobe zaščitne matice - Visoke matice (vse kovine) z režo(-
ami) (ISO 7720:2025)
Fasteners - Prevailing torque hexagon nuts - High nuts (all metal) with slot(s) (ISO
7720:2025)
Verbindungselemente - Sechskantmuttern mit Klemmteil - Hohe Muttern
(Ganzmetallmuttern) mit Schlitz(en) (ISO 7720:2025)
Fixations - Écrous hexagonaux autofreinés - Écrous hauts (tout métal) à fente(s) (ISO
7720:2025)
Ta slovenski standard je istoveten z: EN ISO 7720:2025
ICS:
21.060.20 Matice Nuts
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 7720
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2025
EUROPÄISCHE NORM
ICS 21.060.20
English Version
Fasteners - Prevailing torque hexagon nuts - High nuts (all
metal) with slot(s) (ISO 7720:2025)
Fixations - Écrous hexagonaux autofreinés - Écrous Verbindungselemente - Sechskantmuttern mit
hauts (tout métal) à fente(s) (ISO 7720:2025) Klemmteil - Hohe Muttern (Ganzmetallmuttern) mit
Schlitz(en) (ISO 7720:2025)
This European Standard was approved by CEN on 21 June 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 7720:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 7720:2025) has been prepared by Technical Committee ISO/TC 2 "Fasteners "
in collaboration with Technical Committee CEN/TC 185 “Fasteners” the secretariat of which is held by
BSI.
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 December 2025, and conflicting national standards
shall be withdrawn at the latest by December 2025.
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.
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 7720:2025 has been approved by CEN as EN ISO 7720:2025 without any modification.

International
Standard
ISO 7720
Fourth edition
Fasteners — Prevailing torque
2025-06
hexagon nuts — High nuts (all
metal) with slot(s)
Fixations — Écrous hexagonaux autofreinés — Écrous hauts
(tout métal) à fente(s)
Reference number
ISO 7720:2025(en) © ISO 2025
ISO 7720:2025(en)
© 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 7720:2025(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Dimensions . 2
5 Requirements and reference International Standards . 4
6 Marking and labelling . 5
6.1 Marking on product . .5
6.2 Labelling on package .5
7 Designation . 5
Bibliography . 6

iii
ISO 7720:2025(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 2, Fasteners, Subcommittee SC 12, Fasteners
with metric internal thread, in collaboration with the European Committee for Standardization (CEN)
Technical Committee CEN/TC 185, Fasteners, in accordance with the Agreement on technical cooperation
between ISO and CEN (Vienna Agreement).
This fourth edition cancels and replaces the third edition (ISO 7720:2012) which has been technically
revised.
The main changes are as follows:
— the title and scope have been changed in order to address the nut height: high (instead of style 2); the
design principles of these nuts have been clarified in Scope (see Note);
— property classes have been deleted from title and scope: style, relevant property classes and related
quenching and tempering conditions for steel nuts have been specified in Clause 5 in accordance with
ISO 898-2; property class 9 has been replaced b
...