ISO 6787:2018
(Main)Assembly tools for screws and nuts - Adjustable wrenches
Assembly tools for screws and nuts - Adjustable wrenches
ISO 6787:2018 specifies the dimensions of adjustable wrenches and the admissible clearance of the adjustable jaw. It also specifies test conditions to test the suitability of tool performance.
Outils de manoeuvre pour vis et écrous — Clés à molette
ISO 6787:2018 spécifie les dimensions des clés à molette et le jeu admissible de la mâchoire mobile. Il spécifie également les conditions d'essai en vue de vérifier l'aptitude de l'outil à sa fonction.
General Information
- Status
- Published
- Publication Date
- 03-Apr-2018
- Technical Committee
- ISO/TC 29/SC 10 - Assembly tools for screws and nuts, pliers and nippers
- Drafting Committee
- ISO/TC 29/SC 10 - Assembly tools for screws and nuts, pliers and nippers
- Current Stage
- 9093 - International Standard confirmed
- Start Date
- 26-Jun-2025
- Completion Date
- 13-Dec-2025
Relations
- Effective Date
- 16-Jul-2016
Overview
ISO 6787:2018 specifies the dimensional requirements and performance test conditions for adjustable wrenches used for screws and nuts. The standard defines maximum jaw openings, head and jaw tip dimensions, and the permissible clearance of the adjustable jaw. It also sets key technical requirements for hardness and torsion testing to verify tool suitability and durability.
This edition updates test mandrel and torque values and aligns torque testing with ISO 1711-1 procedures. The standard supports consistent manufacturing, safer use, and interchangeability of adjustable wrenches across markets.
Key Topics
- Dimensions: Nominal wrench lengths, maximum jaw opening, jaw depth and thickness are specified in tabulated form. Designers and manufacturers should use Table 1 dimensions as the baseline for product geometry.
- Jaw clearance: The clearance (c) between adjustable and fixed jaws is measured under a light force. Clearance must not exceed the maximum values defined for each size; the adjustable jaw must travel freely without binding.
- Hardness: Wrenches shall have a minimum hardness of 40 HRC, tested over the whole head to ensure adequate wear and strength.
- Torque (torsion) test: Tests are performed on a hexagon test mandrel hardened to at least 55 HRC, following the procedure in ISO 1711-1. Test torque values vary by wrench length and mandrel width (Table 2) and are applied in both directions. After testing, tools shall show no permanent deformation or defects that affect use.
- Designation and marking: Products are designated with the standard reference, form (A or B), angle (α) and length (l). Example: Wrench ISO 6787 – A 15 × 250. Marking must include nominal length and manufacturer name or trademark.
Applications
ISO 6787:2018 is relevant for:
- Tool manufacturers specifying and verifying adjustable wrench geometry and performance.
- Quality and test laboratories performing hardness and torsion tests on hand tools.
- Procurement teams and engineers seeking consistency, safety, and interchangeability in hand tools used in maintenance, assembly and mechanical work.
Adopting this standard helps reduce product variability, improves user safety by limiting jaw play and ensuring minimum hardness, and provides objective test methods for warranty and acceptance testing.
Related Standards
- ISO 1711-1 - referenced for detailed torque test procedures and general wrench/socket test methods.
- ISO 1703 - relates to designation and classification of assembly tools for screws and nuts.
- ISO 6508-1 - Rockwell hardness test method referenced for hardness verification.
For implementation, consult the full ISO 6787:2018 document for complete tables, figures and test value specifics.
ISO 6787:2018 - Assembly tools for screws and nuts — Adjustable wrenches Released:4/4/2018
ISO 6787:2018 - Outils de manoeuvre pour vis et écrous — Clés à molette Released:4/4/2018
Frequently Asked Questions
ISO 6787:2018 is a standard published by the International Organization for Standardization (ISO). Its full title is "Assembly tools for screws and nuts - Adjustable wrenches". This standard covers: ISO 6787:2018 specifies the dimensions of adjustable wrenches and the admissible clearance of the adjustable jaw. It also specifies test conditions to test the suitability of tool performance.
ISO 6787:2018 specifies the dimensions of adjustable wrenches and the admissible clearance of the adjustable jaw. It also specifies test conditions to test the suitability of tool performance.
ISO 6787:2018 is classified under the following ICS (International Classification for Standards) categories: 25.140.30 - Hand-operated tools. The ICS classification helps identify the subject area and facilitates finding related standards.
ISO 6787:2018 has the following relationships with other standards: It is inter standard links to ISO 6787:2001. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
You can purchase ISO 6787:2018 directly from iTeh Standards. The document is available in PDF format and is delivered instantly after payment. Add the standard to your cart and complete the secure checkout process. iTeh Standards is an authorized distributor of ISO standards.
Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 6787
Third edition
2018-03
Assembly tools for screws and nuts —
Adjustable wrenches
Outils de manoeuvre pour vis et écrous — Clés à molette
Reference number
©
ISO 2018
© ISO 2018
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
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Dimensions . 1
5 Technical specifications . 1
5.1 Clearance of adjustable jaw . 1
5.2 Hardness . 3
5.3 Torque test . 3
6 Designation . 4
7 Marking . 4
Bibliography . 5
Foreword
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...
NORME ISO
INTERNATIONALE 6787
Troisième édition
2018-03
Outils de manoeuvre pour vis et
écrous — Clés à molette
Assembly tools for screws and nuts — Adjustable wrenches
Numéro de référence
©
ISO 2018
DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2018
Tous droits réservés. Sauf prescription différente ou nécessité dans le contexte de sa mise en oeuvre, aucune partie de cette
publication ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique,
y compris la photocopie, ou la diffusion sur l’internet ou sur un intranet, sans autorisation écrite préalable. Une autorisation peut
être demandée à l’ISO à l’adresse ci-après ou au comité membre de l’ISO dans le pays du demandeur.
ISO copyright office
Case postale 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Tél.: +41 22 749 01 11
Fax: +41 22 749 09 47
E-mail: copyright@iso.org
Web: www.iso.org
Publié en Suisse
ii © ISO 2018 – Tous droits réservés
Sommaire Page
Avant-propos .iv
1 Domaine d'application . 1
2 Références normatives . 1
3 Termes et définitions . 1
4 Dimensions . 1
5 Spécifications techniques . 1
5.1 Jeu de la mâchoire mobile . 1
5.2 Dureté . 3
5.3 Essai de torsion . 3
6 Désignation . 4
7 Marquage . 4
Bibliographie . 5
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes
nationaux de normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est
en général confiée aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude
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L'ISO collabore étroitement avec la Commission électrotechnique internationale (IEC) en ce qui
concerne la normalisation électrotechnique.
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décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier de prendre note des différents
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