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 7719:2012) which has been technically revised. It also incorporates the Technical Corrigendum ISO 7719:2012/Cor.1:2013.

The main changes are as follows:

— the design principles of these nuts have been clarified in Scope (see Note);
— 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 (see Table 3);
— stainless steel nuts have been added in accordance with ISO 3506‑2;
— M7, M27, M33 and M39 have been added;
— d _a,max, d_w,min and m_w,min have been specified with two decimal places;
— d _w,min for M5 has been changed from s_min – IT16 to s_min – IT15 in order to have a larger bearing surface area and thus less contact pressure;
— h _min for M5 and M6 has been amended to style 1 in accordance with the scope of this document, and h_max has been decreased accordingly (see Table 1);
— 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.

BS EN ISO 7719:2025

Fasteners. Prevailing torque hexagon nuts. Regular nuts (all metal)

Current

Published:

30 Jun 2025