ISO 12821:2019

Overview

ISO 12821:2019 specifies the dimensional requirements for the 26 H 180 crown finish used on glass beverage bottles. The standard defines the finish profile, sealing surfaces, crimping edge geometry and key measurement points to ensure reliable use with metal crown caps (see EN 17177). Dimensions are given in millimetres and general tolerances follow ISO 9058.

Key topics and requirements

• Finish height: 26 mm tall crown finish (nominal designation 26 H 180).
• Finish diameter and bore: nominal external finish diameter measured at up to 3 mm below the top is 16.5 mm (min.) to 18.0 mm (max.); minimum through-bore 15.5 mm.
• Crimping edge (“P” point): defined contact zone between the glass finish and the corrugated skirt of the cap; recommended radius for optimum performance 0.5–0.8 mm, preferably near 0.5 mm (excluding the mould joint).
• Sealing surface: must be smooth and free of defects; contact between the crown cap liner compound and the internal mould parting line should be avoided. Two alternative detail profiles for the sealing surface are provided.
• Flexibility for non-returnable bottles: a slightly different internal diameter can be agreed in writing between the bottler, glass manufacturer and crown cap manufacturer (see note in standard).
• Tolerances and measurement: general tolerances are governed by ISO 9058; dimensions and inspection references are illustrated across Figures 1–5.

Applications and who uses it

ISO 12821:2019 is intended for professionals involved in the design, manufacture and quality control of beverage glass containers and closures:

• Glass bottle designers and manufacturers (mould design and finishing)
• Bottlers and beverage producers (packaging specifications, supplier agreements)
• Crown cap manufacturers and closure suppliers (cap design compatibility)
• Packaging engineers, quality assurance and conformity assessment teams
• Test labs and inspectors conducting dimensional checks and compatibility testing

Practical uses include ensuring interchangeability of crowns and bottles, guiding mould tooling decisions, preventing sealing failures, and reducing rejection rates in production lines.

Related standards

• EN 17177 - Crown cap dimensions (26 mm diameter, 6 mm height cap) - for cap design compatibility.
• ISO 9058 - Standard tolerances for glass bottles - for dimensional tolerances and inspection criteria.

Using ISO 12821:2019 helps manufacturers and supply-chain partners achieve consistent sealing performance, reliable crimping, and cross-supplier interchangeability for crown-sealed beverage bottles.