Overview
ISO 14368-2:2003 specifies the dimensional requirements of the interface for assembling round mineral and sapphire watch-glasses to a watch case using either adhesive or a gasket. Developed by ISO/TC 114 (Horology), SC 13, this part complements ISO 14368-1 (dimensions and tolerances) and defines the key geometric features and limits that ensure reliable fit and sealing for watch manufacturers and repairers.
Key Topics
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Scope: Requirements apply to round-shaped mineral and sapphire watch-glasses mounted by adhesive or by gasket.
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Opening (dial aperture):
- The standard provides equations to calculate the dial opening diameter relative to glass dimensions and slope heights (referenced to ISO 14368-1 for glass heights).
- Separate formulae are given for adhesive-mounted and gasket-mounted assemblies.
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Glass circular groove:
- Dimensional relationship between groove diameter and glass parameters is defined; for adhesive mounting the groove allowance e is specified (e = 0.03 mm to 0.05 mm).
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Gasket design and dimensions:
- Table-based gasket dimensions and relationships to glass groove geometry are specified.
- Compression c is defined as a percentage of gasket width (typically 15 % to 35 %), and internal slope angles of the gasket (γ) are specified in the range 30° to 45°.
- Heights for internal slopes and gasket fit are provided (internal slope height 0.10 mm to 0.30 mm) and guidance is given to set pre-fit gasket height according to material.
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Assembly methods:
- Two approved methods: (a) place gasket in the glass groove, then drive in the glass, or (b) fit the gasket onto the glass surround then drive into the groove (the latter applies only to certain gasket types).
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Tolerances and references:
- Tolerances for diameters, thickness and heights are referenced to ISO 14368-1 and the ISO system of limits and fits (ISO 286-1 and ISO 286-2).
- Symbols and figures illustrating terms and dimensions are included in the standard for unambiguous interpretation.
Applications
- Ensures consistent assembly and interchangeability of watch-glasses across production batches and suppliers.
- Helps designers and manufacturers achieve correct fit, sealing, and aesthetic alignment when using mineral or sapphire glasses.
- Serves as a reference for quality control, repair workshops, and suppliers of gaskets and adhesives in the horology supply chain.
Related Standards
- ISO 14368-1 - Mineral and sapphire watch-glasses: Dimensions and tolerances (provides glass heights and related parameters used by Part 2).
- ISO 14368-3 - Mineral and sapphire watch-glasses: Qualitative criteria and test methods.
- ISO 286-1 / ISO 286-2 - ISO system of limits and fits: Bases of tolerances and tables of standard tolerance grades (normative references used by this part).
For implementation, consult the full ISO 14368-2:2003 document for figures, tables and exact formulae required for precise machining, gasket specification and assembly procedures.