ISO 3765:1998

Timekeeping instruments - Wristwatches - Dimensions of bracelet-to-case fastening elements

This International Standard specifies the dimensions for fixing a bracelet to a wristwatch-case with the use of spring bars. This International Standard is applicable to wristwatch cases of two types and spring bars of three types.

Instruments horaires — Montres-bracelets — Dimensions de raccordement des bracelets aux boîtes

La présente Norme internationale spécifie les dimensions pour la fixation d'un bracelet à une boîte de montre au moyen de barrettes à ressorts. La présente Norme internationale s'applique à des boîtes de montres-bracelets de deux types et à des barrettes à ressorts de trois types.

General Information

• Status: Published
• Publication Date: 25-Nov-1998
• ICS: 39.040.10 - Watches
• Technical Committee: ISO/TC 114/SC 7 - Overall dimensions
• Drafting Committee: ISO/TC 114/SC 7 - Overall dimensions
• Current Stage: 9093 - International Standard confirmed
• Start Date: 03-Aug-2022
• Completion Date: 13-Dec-2025

Relations

• Revises: ISO 3765:1976 - Timekeeping instruments - Wristwatch cases - Dimensions of fastening elements for bracelets
• Effective Date: 15-Apr-2008

Overview

ISO 3765:1998 is an International Standard developed by the International Organization for Standardization (ISO), focusing on timekeeping instruments-specifically wristwatches. This standard defines the exact dimensions and tolerances for the bracelet-to-case fastening elements used in wristwatches. It specifies the dimensional requirements for fastening a bracelet to a wristwatch case via the use of spring bars, ensuring compatibility and interchangeability in the horological industry.

The standard applies to two types of wristwatch cases and three distinct types of spring bars, offering comprehensive guidance for manufacturers to maintain consistency, durability, and reliable assembly between bracelets and watch cases.

Key Topics

• Types of Wristwatch Cases

  • Type 1: Cases with two lugs on opposite sides, where bracelets attach using spring bars.
  • Type 2: Similar to Type 1, but the lugs are integrated with a cover on their upper surface for additional design or protection.

• Spring Bar Classifications

  • Type 1: Spring bar with two moving pins.
  • Type 2: Spring bar with a single moving pin.
  • Type 3: Curved spring bar designed to match specific case shapes.

• Dimensions and Tolerances

  • The standard provides precise measurements including:
    • Distance between lugs
    • Clearance for the spring bar pivot
    • Diameter and useful depth of holes in the lugs
    • Length and diameter of spring bar components such as pins, collars, and bodies
  • It incorporates ISO 286-1 guidelines for limits, fits, and tolerances to ensure accuracy and interchangeability.

• Definitions and Terms

  • Case: Protective housing where the watch movement is mounted.
  • Lug: Part of the watch case with holes for fastening the bracelet.
  • Spring bar: A unit containing a spring mechanism for securing the bracelet to the case.

Applications

ISO 3765:1998 serves as a foundational reference for:

• Watch Manufacturers: Ensures that bracelet-to-case fastening parts meet international precision standards for mechanical reliability.
• Component Suppliers: Supplies standardized spring bars and case lugs made to exact dimensions for seamless integration.
• Repair and Aftermarket Services: Facilitates replacement of bracelets or spring bars without compatibility issues.
• Quality Assurance: Helps maintain uniformity in mass production and supports testing methods based on dimensional conformity.
• Design and Engineering: Assists in designing new wristwatch models that comply with globally recognized fastening specifications.

By adhering to these specifications, stakeholders can achieve better product reliability, customer satisfaction, and streamlined production processes.

Related Standards

• ISO 286-1:1988: This standard establishes the system of limits, fits, tolerances, and deviations referenced for dimensional accuracy.
• ISO 6426-2:1984: Covers horological vocabulary, providing technical and commercial definitions relevant to watch components and assembly.
• General Horology Standards: For broader horological practices, ISO/TC 114 and its subcommittees oversee related wristwatch dimensions and testing protocols.

Summary

ISO 3765:1998 ensures that wristwatch bracelets and cases connect securely through standardized fastening elements. Its detailed specifications for spring bars and case lugs promote interoperability and durability, crucial for manufacturers and consumers worldwide. Incorporating this standard simplifies component sourcing and repair, ultimately supporting the horological industry's goal of precision timekeeping combined with ergonomic and aesthetic design.

Keywords: ISO 3765:1998, wristwatch standards, bracelet fastening, spring bars, watch case dimensions, horology, watch manufacturing standards, watch bracelet attachment, component tolerances, watch lugs, watch spring bars.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 3765
Second edition
1998-11-15
Timekeeping instruments —
Wristwatches — Dimensions of bracelet-to-
case fastening elements
Instruments horaires — Montres-bracelets — Dimensions de raccordement
des bracelets aux boîtes
A
Reference number
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.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
International Standard ISO 3765 was prepared by Technical Committee ISO/TC 114, Horology, Subcommittee
SC 7, Overall dimensions.
This second edition cancels and replaces the first edition (ISO 3765:1976), which has been technically revised.
©  ISO 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet [e-mail]
Printed in Switzerland
ii
INTERNATIONAL STANDARD  © ISO
Timekeeping instruments — Wristwatches — Dimensions
of bracelet-to-case fastening elements
1 Scope
This International Standard specifies the dimensions for fixing a bracelet to a wristwatch-case with the use of spring
bars.
This International Standard is applicable to wristwatch cases of two types and spring bars of three types.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this
International Standard. At the time of publication, the editions indicated were valid. All standards are subject to
revision, and parties to agreements based on this International Standard are encouraged to investigate the
possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain
registers of currently valid International Standards.
ISO 286-1:1988, ISO system of limits and fits — Part 1: Bases of tolerances, deviations and fits.
ISO 6426-2:1984,
...

NORME ISO
INTERNATIONALE 3765
Deuxième édition
1998-11-15
Instruments horaires — Montres-
bracelets — Dimensions de raccordement
des bracelets aux boîtes
Timekeeping instruments — Wristwatches — Dimensions of bracelet-to-
case fastening elements
A
Numéro de référence
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 a le droit de faire partie du comité
technique créé à cet effet. Les organisations internationales, gouvernementales et non gouvernementales, en
liaison avec l'ISO participent également aux travaux. L'ISO collabore étroitement avec la Commission
électrotechnique internationale (CEI) en ce qui concerne la normalisation électrotechnique.
Les projets de Normes internationales adoptés par les comités techniques sont soumis aux comités membres pour
vote. Leur publication comme Normes internationales requiert l'approbation de 75 % au moins des comités
membres votants.
La Norme internationale ISO 3765 a été élaborée par le comité technique ISO/TC 114, Horlogerie, sous-comité
SC 7, Dimensions de raccordement.
Cette deuxième édition annule et remplace la première édition (ISO 3765:1976), dont elle constitue une révision
technique.
©  ISO 1998
Droits de reproduction réservés. Sauf prescription différente, 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 et les microfilms, sans l'accord écrit de l'éditeur.
Organisation internationale de normalisation
Case postale 56 • CH-1211 Genève 20 • Suisse
Internet [e-mail]
Imprimé en Suisse
ii
NORME INTERNATIONALE  © ISO ISO 3765:1998(F)
Instruments horaires — Montres-bracelets — Dimensions
de raccordement des bracelets aux boîtes
1 Domaine d’application
La présente Norme internationale spécifie les dimensions pour la fixation d’un bracelet à une boîte de montre au
moyen de barrettes à ressorts.
La présente Norme internationale s’applique à des boîtes de montres-bracelets de deux types et à des barrettes à
ressorts de trois types.
2 Références normatives
Les normes suivantes contiennent des dispositions qui, par suite de la référence qui en est faite, constituent des
dispositions valables pour la présente Norme internationale. Au moment de la publication, les éditions indiquées
étaient en vigueur. Toute norme est sujette à révision et les parties prenantes des accords fondés sur la présente
Norme internationale sont invitées à rechercher la possibilité d'appliquer les éditions les plus récentes des normes
indiquées ci-après. Les membres de la CEI et de l'ISO possèdent le registre des Normes internationales en vigueur
à un moment donné.
ISO 286-1:1988, Système ISO de tolérances et d’ajustements — Partie 1: Base des tolérances, écarts et
ajustements.
ISO 6426-2:1984, Vocabulaire horloger — Partie 2: Définitions technico-commerciales.
...