kSIST FprEN ISO 7720:2025

Fasteners - Prevailing torque hexagon nuts - High nuts (all metal) with slot(s) (ISO/FDIS 7720:2025)

This document specifies the characteristics of prevailing torque (all metal) hexagon high nuts with slot(s), in steel and stainless steel, with metric coarse pitch thread M5 to M39, and with product grades A and B.
NOTE            These nuts are designed with mmin as specified ISO 4032 and with an overall height h greater than in ISO 7042, in order to accommodate the prevailing torque feature with slot(s); this height h contributes to the nut resistance due to the number of engaged threads. hmin values have been calculated as a function of hmax together with a ratio hmax/D that progresses regularly with increasing diameter; therefore, the tolerance (hmax – hmin) does not follow the ISO code system for tolerances (IT system).
If in certain cases other specifications are requested, property classes and stainless steel grades can be selected from ISO 898-2 or ISO 3506-2.

Verbindungselemente - Sechskantmuttern mit Klemmteil - Hohe Muttern (Ganzmetallmuttern) mit Schlitz(en) (ISO/FDIS 7720:2025)

Dieses Dokument legt die Eigenschaften von hohen Sechskantmuttern mit Klemmteil (Ganzmetallmuttern) mit Schlitz(en) aus Stahl und nichtrostendem Stahl mit metrischen Regelgewinden von M5 bis M39, und in Produktklassen A und B fest.
ANMERKUNG   Diese Muttern sind mit mmin wie in ISO 4032 festgelegt und mit einer Gesamthöhe h mehr als in ISO 7042 gestaltet, um das Klemmteil mit Schlitz(en) aufzunehmen; diese Höhe h trägt aufgrund der Anzahl der eingeschraubten Gewinde zum Widerstand der Mutter bei. Die hmin-Werte wurden als Funktion von hmax zusammen mit einem Verhältnis hmax/D berechnet, das sich mit zunehmendem Durchmesser regelmäßig erhöht; daher entspricht die Toleranz (hmax − hmin) nicht dem ISO-Toleranzsystem (IT-System).
Falls in bestimmten Fällen andere Festlegungen benötigt werden, können Festigkeitsklassen und Stahlsorten nichtrostender Stähle ISO 898 2 oder ISO 3506 2 entnommen werden.

Fixations - Écrous hexagonaux autofreinés - Écrous hauts (tout métal) à fente(s) (ISO/FDIS 7720:2025)

Le présent document spécifie les caractéristiques des écrous hauts hexagonaux autofreinés (tout métal) à fente(s), en acier et en acier inoxydable, à filetage métrique à pas gros M5 à M39, et de grades A et B.
NOTE            Ces écrous sont conçus avec mmin tel que spécifié dans l’ISO 4032 et avec une hauteur totale h plus importante que dans l’ISO 7042, pour être adaptés au dispositif d’autofreinage avec fente(s); cette hauteur h contribue à la résistance de l’écrou grâce au nombre de filets en prise. Les valeurs de hmin ont été calculées en fonction de hmax et en prenant en compte un ratio hmax/D qui augmente régulièrement avec le diamètre; de ce fait, la tolérance (hmax – hmin) ne s’intègre pas dans le système de codification ISO pour les tolérances (IT system).
Si dans certains cas d’autres spécifications sont requises, les classes de qualité et les grades d’acier inoxydable peuvent être choisis dans l’ISO 898-2 ou l’ISO 3506-2.

Vezni elementi - Šestrobe zaščitne matice - Visoke matice (vse kovine) z režo(-ami) (ISO/FDIS 7720:2025)

General Information

• Status: Not Published
• Public Enquiry End Date: 30-Jul-2024
• ICS: 21.060.20 - Nuts
• Technical Committee: ISEL - Mechanical elements
• Current Stage: 5020 - Formal vote (FV) (Adopted Project)
• Start Date: 17-Apr-2025
• Due Date: 05-Jun-2025
• Completion Date: 17-Apr-2025
• Ref Project: EN ISO 7720:2025 - Fasteners - Prevailing torque hexagon nuts - High nuts (all metal) with slot(s) (ISO 7720:2025)

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN ISO 7720:2024
01-julij-2024
Vezni elementi - Šestrobe zaščitne matice - Visoke matice (vse kovine) z režo(-
ami) (ISO/DIS 7720:2024)
Fasteners - Prevailing torque hexagon nuts - High nuts (all metal) with slot(s) (ISO/DIS
7720:2024)
Verbindungselemente - Sechskantmuttern mit Klemmteil - Hohe Muttern
(Ganzmetallmuttern) mit Schlitz(en) (ISO/DIS 7720:2024)
Fixations - Écrous hexagonaux autofreinés - Écrous hauts (tout métal) à fente(s)
(ISO/DIS 7720:2024)
Ta slovenski standard je istoveten z: prEN ISO 7720
ICS:
21.060.20 Matice Nuts
oSIST prEN ISO 7720:2024 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN ISO 7720:2024
oSIST prEN ISO 7720:2024
DRAFT
International
Standard
ISO/DIS 7720
ISO/TC 2/SC 12
Fasteners — Prevailing torque
Secretariat: DIN
hexagon nuts — High nuts (all
Voting begins on:
metal) with slot(s)
2024-06-06
Fixations — Écrous hexagonaux autofreinés — Écrous hauts
Voting terminates on:
(tout métal) à fente(s)
2024-08-29
ICS: 21.060.20
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
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 SUPPORTING DOCUMENTATION.
Reference number
ISO/DIS 7720:2024(en)
oSIST prEN ISO 7720:2024
DRAFT
ISO/DIS 7720:2024(en)
International
Standard
ISO/DIS 7720
ISO/TC 2/SC 12
Fasteners — Prevailing torque
Secretariat: DIN
hexagon nuts — High nuts (all
Voting begins on:
metal) with slot(s)
Fixations — Écrous hexagonaux autofreinés — Écrous hauts
Voting terminates on:
(tout métal) à fente(s)
ICS: 21.060.20
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2024
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
ISO copyright office
RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: [phone]
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 7720:2024(en)
ii
oSIST prEN ISO 7720:2024
ISO/DIS 7720:2024(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 . 3
6 Marking and labelling . 4
6.1 Marking on product . .4
6.2 Labelling on package .5
7 Designation . 5
Bibliography . 6

iii
oSIST prEN ISO 7720:2024
ISO/DIS 7720:2024(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 documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent
rights identified during the development of the document will be in the Introduction and/or on the ISO list of
patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 2, Fasteners, Subcommittee SC 12, Fasteners
with metric internal thread.
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 by property classes 8 and 10; see Table 3;
— stainless steel nuts have been added in accordance with ISO 3506-2;
— M7, M18, M22, M27, M33 and M39 have been added;
— d has been specified with two decimal places;
a,max
— d for M5 has been changed from s – IT16 to s – IT15 in order to have a larger bearing surface
w,min min min
area and thus less contact pressure;
— m has been added with values in accordance with style 1; m = 0,8 m has been specified in
min w,min min
accordance with ISO 4759-1;
— the overall (total) height of the nut, h and h , have been increased to accommodate the prevailing
max min
torque feature with slot(s);
— specifications for marking and labelling have been added as Clause 6.
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
oSIST prEN ISO 7720:2024
DRAFT International Standard ISO/DIS 7720:2024(en)
Fasteners — Prevaili
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