Overview
ISO 5059-1:2025 - Geometrical product specifications (GPS) - Part 1 specifies the principal design and metrological characteristics of two-point inside micrometers. The standard applies to analogue and digital two-point inside micrometers with scale intervals or digital steps of 0.001 mm and 0.01 mm, and to instruments with or without interchangeable extensions. It explicitly excludes micrometers fitted with a dial gauge and jaw micrometers. ISO 5059-1:2025 is part of the ISO 5059 series and is positioned within the GPS framework for dimensional measuring equipment.
Key topics
The standard defines requirements and test guidance for core technical areas, including:
- Design characteristics and nomenclature (main dimensions, measuring faces, thermally insulating grip).
- Metrological characteristics such as rated operating conditions, reference point definition, and length measurement error.
- Test methods for evaluating instrument performance under rated conditions.
- Maximum permissible error (MPE) and default MPE values (provided in annexes) for length measurement.
- Interchangeable extensions: requirements and effect on measurement error.
- Conformity assessment: procedures for determining compliance, handling measurement uncertainty, and decision rules.
- Marking and documentation requirements for identification and traceability.
- Informative and normative annexes that link the standard to the GPS matrix model and provide default MPE values.
Keywords naturally integrated: ISO 5059-1:2025, two-point inside micrometers, dimensional measuring equipment, metrological characteristics, MPE, interchangeable extensions, measurement uncertainty.
Applications
ISO 5059-1:2025 is practical for:
- Manufacturers designing and producing two-point inside micrometers to meet internationally recognized GPS requirements.
- Calibration and testing laboratories that perform verification, calibration, and conformity assessment of inside micrometers.
- Quality assurance and inspection teams in manufacturing sectors (precision engineering, aerospace, automotive, tooling) that rely on accurate internal diameter measurements.
- Procurement and specification authors who need to define acceptance criteria and performance requirements for inside micrometers.
- Metrologists and standards specialists integrating micrometer performance into measurement systems and uncertainty budgets.
Practical uses include instrument selection, acceptance testing, calibration scheduling, specifying MPEs for inspection protocols, and ensuring traceable measurement processes.
Related standards
ISO 5059-1:2025 is linked within the GPS system. Relevant standards referenced in its introduction include:
- ISO 14638 (GPS general standards overview)
- ISO 8015 (fundamental GPS rules)
- ISO 14253-1 (decision rules and conformity)
- ISO/TR 14253-6 (decision rule selection guidance)
Also consult other parts of the ISO 5059 series for complementary guidance on dimensional measuring equipment.