BS EN ISO 1938-1:2026 — What Changed and What To Do
BS EN ISO 1938-1:2026 updates plain limit gauge requirements with revised definitions, new gauge forms and updated metrological limits for dimensional verification up to 500 mm.
What is BS EN ISO 1938-1:2026?
BS EN ISO 1938-1:2026 is a requirements standard for plain limit gauges used in dimensional verification of linear sizes up to 500 mm. It defines gauge types, design and metrological characteristics, and maximum permissible limits for new and worn states. The standard applies to quality, inspection and metrology professionals across aerospace, automotive, rail, defence, nuclear and general manufacturing.
What changed?
- Supersedes the 2015 edition and introduces targeted technical updates to improve clarity and reflect current international consensus.
- Revised definitions to remove ambiguity in terms related to gauge types, characteristics and limits.
- Updated design and metrological characteristics for GO gauge types B to K.
- New gauge forms added — full form cylindrical ring gauges, notch gauges and gap gauges — to support consistent verification across a wider range of applications.
- Maximum permissible limits (MPLs) for new and wear states are updated to align with modern manufacturing accuracy expectations.
Key dates and facts
| Published | 2026-06-30 |
| Supersedes | BS EN ISO 1938-1:2015 |
| Previous edition withdrawn | Not stated in source — confirm with your certification body |
| Certifiable | Yes — requirements standard |
What should you do?
- Review your gauge inventory and calibration records to identify any plain limit gauges affected by the updated design characteristics for GO types B to K.
- Update your gauge design and procurement specifications to include the newly recognised gauge forms (full form cylindrical ring, notch and gap gauges) where applicable.
- Revise your inspection procedures and work instructions to reflect the revised definitions and maximum permissible limits for new and worn states.
- Verify your supplier qualification and incoming inspection processes to ensure consistency in dimensional verification across your supply chain.
- Check your internal audit programme for coverage of dimensional measurement equipment against the updated requirements.
This summary is provided for information only and does not constitute professional or compliance advice. Verify against the published standard. ITMAD accepts no liability for any action taken in reliance on it.