EN ISO 7042:2025

Fasteners - Prevailing torque hexagon nuts - High nuts (all metal) (ISO 7042:2025)

This document specifies the characteristics of prevailing torque (all metal) hexagon high nuts, 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 an overall heigth hmin = mmin (as specified in ISO 898-2 and ISO 4033 for style 2) plus the prevailing torque feature. hmax has been established in function of hmin; therefore, the tolerance (hmax – hmin) does not follow the ISO code system for tolerances (IT system). The wrenching height mw,min corresponds to the values specified for style 1.
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) (ISO 7042:2025)

Dieses Dokument legt die Eigenschaften von hohen Sechskantmuttern mit Klemmteil (Ganzmetallmuttern) aus Stahl und nichtrostendem Stahl mit metrischen Regelgewinden von M5 bis M39, und in Produktklassen A und B fest.
ANMERKUNG   Diese Muttern sind mit einer Gesamthöhe von hmin = mmin (wie in ISO 898 2 und ISO 4033 für den Typ 2 festgelegt) plus Klemmteil gestaltet. hmax wurde als Funktion von hmin festgelegt, daher entspricht die Toleranz (hmax − hmin) nicht dem ISO-Code-System für Toleranzen (IT-System). Die Verrenkungshöhe mw,min entspricht den für Typ 1 angegebenen Werten.
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) (ISO 7042:2025)

Le présent document spécifie les caractéristiques des écrous hauts hexagonaux autofreinés (tout métal), 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 une hauteur totale hmin = mmin (tel que spécifié dans l'ISO 898-2 et l'ISO 4033 pour le style 2) plus le dispositif d’autofreinage. Les valeurs de hmax ont été calculées en fonction de hmin, de ce fait la tolérance (hmax – hmin) ne s’intègre pas dans le système de codification ISO pour les tolérances (IT system). La hauteur de prise de clé mw,min correspond aux valeurs spécifiées pour le style 1.
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) (ISO 7042:2025)

Ta dokument določa značilnosti visokih šestrobih zaščitnih matic (vse kovine) iz jekla in nerjavnega jekla, z grobim metrskim navojem velikosti od M5 do M39 ter razredoma izdelave A in B. OPOMBA:            Te matice so zasnovane s skupno višino hmin = mmin (kot je določeno v standardih ISO 898-2 in ISO 4033 za tip 2) in s samozavorno funkcijo. Vrednost hmax je določena glede na vrednost hmin; zato toleranca (hmax – hmin) ni skladna s sistemom kod ISO za tolerance (sistem IT). Višina dela matice za prijem ključa (mw,min) ustreza vrednostim, določenim za tip 1. Če se v določenih primerih zahtevajo druge specifikacije, je razrede lastnosti in vrste nerjavnega jekla mogoče izbrati v skladu s standardom ISO 898-2 ali ISO 3506-2.

General Information

• Status: Published
• Publication Date: 24-Jun-2025
• ICS: 21.060.20 - Nuts
• Technical Committee: CEN/TC 185 - Threaded and nonthreaded mechanical fasteners and accessories
• Drafting Committee: CEN/TC 185 - Threaded and nonthreaded mechanical fasteners and accessories
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 25-Jun-2025
• Completion Date: 25-Jun-2025
• Ref Project: SIST EN ISO 7042:2025 - Fasteners - Prevailing torque hexagon nuts - High nuts (all metal) (ISO 7042:2025)

Relations

• Replaces: EN ISO 7042:2012 - Prevailing torque type all-metal hexagon high nuts - Property classes 5, 8, 10 and 12 (ISO 7042:2012)
• Effective Date: 19-Jan-2023

Overview

EN ISO 7042:2025 - Fasteners: Prevailing torque hexagon high nuts (all metal) specifies the characteristics of all‑metal prevailing‑torque hexagon high nuts in steel and stainless steel, for metric coarse‑pitch threads M5 to M39, and for product grades A and B. The standard defines dimensions, tolerances, functional requirements and marking/labelling rules for these locking (prevailing torque) nuts as endorsed by CEN (European adoption of ISO 7042:2025).

Key topics and technical requirements

• Scope and design: Covers hexagon high nuts with an integrated prevailing‑torque feature (shape at manufacturer’s discretion within the hex outside profile). Overall height hmin = mmin (style 2 base) plus the prevailing torque feature; hmax is set relative to hmin and does not follow the ISO IT tolerance code. Wrenching height corresponds to style 1.
• Size range and dimensions: Thread sizes from M5 to M39 (tables and figures specify a, d, h, s, w and other dimensions). Some new sizes (e.g., M7, M18, M22, M27, M33, M39) are included in this edition.
• Materials and grades:
  • Steel nuts: property classes per ISO 898‑2; quenching/tempering and NQT/QT options as referenced.
  • Stainless steel nuts: grades and property classes per ISO 3506‑2 (common grades A2, A4 listed; other grades selectable as required).
• Product grades: Grade A for D ≤ M16 (with special note for M5 thread bearing area); grade B for D > M16.
• Threads and tolerances: Default thread tolerance class 6H; 6G may be specified for coated nuts. Thread standard is ISO 965‑1.
• Functional tests and coatings: Functional properties for steel nuts reference ISO 2320. Surface finishes, electroplated coatings and zinc‑flake systems reference ISO 4042 and ISO 10683. Surface discontinuities and acceptance use ISO 6157‑2 and ISO 3269.
• Marking & labelling: Clause added specifying marking on product and labelling on packaging (steel marking follows ISO 898‑2).

Applications and users

• Practical uses: selection and specification of all‑metal prevailing‑torque hexagon high nuts for mechanical assemblies requiring vibration resistance and secure locking where a metal‑on‑metal prevailing feature is preferred.
• Who uses this standard:
  • Fastener manufacturers and designers
  • Mechanical/assembly engineers and procurement specialists
  • Quality, testing and inspection teams
  • Standards bodies and compliance teams in industry sectors using metric fasteners

Related standards (selection)

• ISO 898‑2 - mechanical properties of nuts (steel)
• ISO 3506‑2 - stainless steel nuts
• ISO 2320 - prevailing torque steel nuts (functional properties)
• ISO 965‑1, ISO 4759‑1, ISO 4042, ISO 10683, ISO 3269, ISO 6157‑2

EN ISO 7042:2025 is essential when specifying metric prevailing‑torque high hex nuts (M5–M39) to ensure dimensional compatibility, mechanical performance and conformity with European/ISO fastener practice.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2025
Vezni elementi - Šestrobe zaščitne matice - Visoke matice (vse kovine) (ISO
7042:2025)
Fasteners - Prevailing torque hexagon nuts - High nuts (all metal) (ISO 7042:2025)
Verbindungselemente - Sechskantmuttern mit Klemmteil - Hohe Muttern
(Ganzmetallmuttern) (ISO 7042:2025)
Fixations - Écrous hexagonaux autofreinés - Écrous hauts (tout métal) (ISO 7042:2025)
Ta slovenski standard je istoveten z: EN ISO 7042:2025
ICS:
21.060.20 Matice Nuts
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 7042
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2025
EUROPÄISCHE NORM
ICS 21.060.20 Supersedes EN ISO 7042:2012
English Version
Fasteners - Prevailing torque hexagon nuts - High nuts (all
metal) (ISO 7042:2025)
Fixations - Écrous hexagonaux autofreinés - Écrous Verbindungselemente - Sechskantmuttern mit
hauts (tout métal) (ISO 7042:2025) Klemmteil - Hohe Muttern (Ganzmetallmuttern) (ISO
7042:2025)
This European Standard was approved by CEN on 20 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 7042:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 7042:2025) 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.
This document supersedes EN ISO 7042:2012.
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 7042:2025 has been approved by CEN as EN ISO 7042:2025 without any modification.

International
Standard
ISO 7042
Fourth edition
Fasteners — Prevailing torque
2025-06
hexagon nuts — High nuts (all metal)
Fixations — Écrous hexagonaux autofreinés — Écrous hauts
(tout métal)
Reference number
ISO 7042:2025(en) © ISO 2025
ISO 7042:2025(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: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 7042:2025(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 7042:2025(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 7042:2012) which has been technically
revised.
The main changes are as follows:
— the design principles of these
...