Overview
EN ISO 9100-4:2005 (ISO 9100-4:2005) defines the dimensional requirements for a vacuum lug finish with a nominal size of 38 mm medium used on wide‑mouth glass containers. This European adoption of the ISO document provides standardized geometry, tolerances and design notes that ensure compatibility between glass jars and vacuum‑lug closures used for vacuum sealing (e.g., food jars, preserves). The standard specifies key diameters, thread/lead geometry and inspection guidance as shown in its figures and Table 1.
Key topics and requirements
- Scope: Dimensions and design of the 38 mm medium vacuum lug finish for wide‑mouth glass containers.
- Critical dimensions: The document gives the principal finish diameters (E and T) with tolerances (e.g., E = 34.75 ±0.35 mm; T = 37.15 ±0.35 mm) and the sealing/closure diameter (C = 27.60 mm) as recorded in Table 1.
- Thread and lead geometry: Specifies cutter/lead angles (α ≈ 10°), thread parameters (thread angle ~12°40′), pitch (25.40 mm = 1 in), and minimum chord dimensions - all important for cap engagement and vacuum function.
- Surface and concentricity: Sealing surface must be free of checks, dips and defects; finish ovality should be minimised and diameters (E and T) should be concentric.
- Mould and tooling guidance: Stop faces on leads must be sharp and perpendicular to the E‑wall; worn mould contours must be replaced to maintain cap‑stopping function and sealing integrity.
- Tolerances: General dimensional tolerances are to be applied in accordance with ISO 2768‑1 where not individually specified.
- Design notes: Cross‑hatched closure position and optional bead/contour guidance are provided to ensure sufficient clearance for closures.
Applications and users
This standard is essential for:
- Glass container designers and manufacturers specifying finish geometry for vacuum‑sealed jars and wide‑mouth containers.
- Closure and cap manufacturers designing vacuum lug closures for compatibility and reliable sealing.
- Packaging engineers and quality teams ensuring interchangeability and leak‑free vacuum packing (food, preserves, cosmetics).
- Tooling/mould makers and production engineers who need the precise cutter, lead and mould contour specifications for manufacturing.
- Procurement and compliance officers requiring standardized specs for supplier contracts.
Using EN ISO 9100-4:2005 helps ensure consistent sealing performance, interchangeability across suppliers and reduced rejects due to poor fit or worn tooling.
Related standards
- ISO 9100 series (other parts cover different nominal sizes and profiles: Parts 1–14).
- ISO 2768‑1 (general tolerances for linear and angular dimensions).
