Overview
ISO 14856:2001 - Timekeeping instruments - Wristwatch-cases - Fixing dimensions of non-spring-bar types defines standardized fixing dimensions for wristwatch cases where bracelets or straps are attached using fixing pins and tubes (non-spring-bar types). The International Standard applies to cases with either four lugs (Type 1) or two single lugs (Type 2) and provides dimensional tables, tolerances and typical fixing-element forms to ensure mechanical compatibility and interchangeability between watch cases, bracelets/straps and fixing parts.
Key topics and technical requirements
- Scope and classification
- Applies to wristwatch-cases with four lugs (Type 1) or two simple lugs (Type 2).
- Fixing element forms
- Illustrations and descriptions of split (fended) pins and tubes and notched pins and tubes are provided (Figures 3–4).
- Dimensional tables
- Tables for Type 1 and Type 2 cases list:
- Distance between lugs (A) and lug width (a)
- Diameter of lug holes (D) and clearance values between tube and case
- Preferred sizes are indicated (marked with an asterisk) and dimensions are given in millimetres.
- Assembly tolerances
- Table for assembly specifies outer tube diameters and pin diameters with ISO tolerance grades (for example h8/h9, js10/js11 and case hole tolerances H11–H15, H12/H13).
- References to ISO tolerance system
Practical applications and users
- Watch case manufacturers - design and produce lug geometries and hole diameters that ensure correct fits for standard pins/tubes.
- Bracelet and strap suppliers - match pin/tube sizes and tolerances to case dimensions for reliable assembly.
- Pin/tube component manufacturers - produce fixing elements to specified diameter and tolerance grades.
- Watch designers and engineers - ensure interchangeability across suppliers and models, and select preferred dimensions.
- Repair and service technicians - use standard dimensions to source compatible replacement pins, tubes and straps.
- Quality assurance teams - verify conformance using the standard’s dimensional tables and ISO tolerance references.
Benefits include improved interchangeability, predictable mechanical fit, reduced rework and clearer procurement/specification language for watchmaking supply chains.
Related standards
- ISO 3765 - Wristwatches - Connection dimensions for bracelets to watch-cases
- ISO 286‑1 / ISO 286‑2 - ISO system of limits and fits (tolerances)
- ISO 6426‑2 - Horological vocabulary (technical-commercial definitions)
Keywords: ISO 14856:2001, wristwatch cases, fixing dimensions, non-spring-bar, lug width, watch pins, tubes, tolerances, watchmaking, horology.
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