Overview
ISO 21005:2018 specifies requirements for thermally toughened safety glass panes used in ship windows and side scuttles. Applicable to glass that fits windows complying with ISO 3903 and side scuttles complying with ISO 1751, the standard covers materials and finish, dimensions for interchangeability, tolerances, parallelism and flatness, testing, marking and designation. This third edition (2018) updates the previous 2012 edition and includes technical revisions to Annex A (thickness calculation factors).
Key Topics and Requirements
- Material: Thermally toughened safety glass manufactured from plate glass (float or polished).
- Finish and strength: Finished panes must meet strength requirements of ISO 614; if finishing reduces strength, either change the finish or increase thickness.
- Dimensions and interchangeability:
- Detailed nominal sizes and thicknesses for ordinary rectangular windows (light-type and heavy-type designations) and for side scuttles (types A, B, C).
- Provision for agreeing other sizes between parties, with thickness calculated per Annex A.
- Edges: All edge work must be smooth-ground and completed before toughening.
- Parallelism and flatness: Maximum permissible deviations are specified (illustrated by figures in the standard) to ensure optical quality and correct fit.
- Testing and sampling:
- Glass panes are tested per ISO 614 (non-destructive punch method referenced).
- Batch sampling rules: test each pane in batches ≤ 4; for larger batches test a random sample of four panes or 2% of the batch, whichever is greater.
- Acceptance criteria: tested panes must remain unbroken and undamaged; specific re-test and rejection rules apply if samples fail.
- Marking: Each pane must be marked in accordance with ISO 614.
- Annex A: Normative guidance for calculating required glass thickness based on dimensions, pressure, and a factor β (graph provided). The 2018 revision adjusted factors used in thickness equations (side scuttle factor set to 1.21).
Applications
ISO 21005:2018 is used by:
- Ship designers and naval architects specifying windows and side scuttles
- Shipyards and marine fabricators procuring or installing glass panes
- Glass manufacturers producing thermally toughened panes for marine use
- Classification societies and inspectors verifying compliance
- Procurement professionals and suppliers ensuring interchangeability and safety compliance
Practical benefits include consistent safety performance, reliable interchangeability of replacement panes, clear testing and sampling procedures, and documented thickness calculation for non-standard sizes.
Related Standards
- ISO 3903 - Ships’ ordinary rectangular windows
- ISO 1751 - Ships’ side scuttles
- ISO 614 - Toughened safety glass panes - Punch method of non-destructive strength testing
- ISO 6345 - Vocabulary for windows and side scuttles
Keywords: ISO 21005:2018, thermally toughened safety glass, marine windows, side scuttles, ship glass, thickness calculation, testing, ISO 3903, ISO 1751, ISO 614.