Overview
EN ISO 9100-3:2005 - also published as ISO 9100-3:2005 - is the international/CEN standard that specifies the dimensional and design requirements for a vacuum lug finish with a nominal size of 38 mm (38 regular) used on wide‑mouth glass containers. It is part of the ISO 9100 series covering vacuum lug finishes for a range of container neck sizes and provides the drawings, dimensional limits and basic functional requirements needed to ensure compatible, reliable vacuum sealing of glass jars and wide‑mouth bottles.
Key topics and technical requirements
- Scope and drawings: Dimensions and design details are defined by the standard’s figures and Table 1 (metric dimensions in millimetres).
- Nominal size: Targets the 38 mm regular finish commonly used for wide‑mouth containers.
- Thread and lug geometry: Specifies thread parameters, pitch/threads-per-inch, leads and cutter inclination (α) to ensure mating with closures.
- Sealing surface requirements: The sealing face must be free of checks, dips, crizzles and defects that could compromise vacuum sealing.
- Concentricity and ovality control: The E and T finish diameters should be concentric and ovality kept to a minimum to ensure reliable cap engagement and vacuum integrity.
- Stop faces and mould maintenance: Leads’ stop faces should be sharp‑edged and as perpendicular to the E‑wall as possible; mould wear must be controlled to maintain functional contours.
- Tolerance guidance: General linear and angular tolerances are applied in accordance with ISO 2768‑1 unless otherwise specified.
- Series context: ISO 9100 is a multipart standard - Part 1 (general) and other parts (e.g., Part 2: 33 medium; Part 4: 38 medium) address other nominal sizes and related details.
Applications and who uses this standard
- Glass container manufacturers and mould designers - to produce neck finishes that are interchangeable and vacuum-capable.
- Closure and cap manufacturers - to design compatible lids and gaskets for vacuum sealing.
- Packaging engineers and bottlers - to select appropriate container/closure systems for food, preserves, cosmetics and other vacuum-packed products.
- Quality control and inspection teams - to verify dimensional compliance, sealing surface integrity and concentricity.
- Suppliers and procurement - to specify accepted finish standards in contracts and product specifications.
Practical value
Adopting EN ISO 9100-3:2005 ensures interchangeability between glass containers and closures, improves vacuum sealing reliability, reduces product loss from faulty seals, and simplifies tooling and quality control by using a common, internationally recognized finish standard.
Related standards
- ISO 2768‑1 (general tolerances) - normative reference for tolerances.
- Other parts of ISO 9100 (Parts 1–14) - for general requirements and other nominal finish sizes.