Overview
ISO 1132-2:2001 - Rolling bearings - Tolerances - Part 2: Measuring and gauging principles and methods sets out guidelines for measuring dimensions, running accuracy and internal clearance of rolling bearings. Published in 2001 as the first edition, it complements ISO 1132-1 (terms and definitions) by describing the fundamental measuring and gauging principles and practical methods used by manufacturers and inspection laboratories. The standard clarifies measurement fundamentals without mandating a single, exclusive method; specified methods may be referenced in disputes.
Key topics and technical requirements
- Measurement scope: Dimensions, runouts (radial and axial), thickness variation, raceway parallelism, surface perpendicularity, chamfer dimensions and radial clearance.
- General conditions: Recommendations on measuring equipment, masters/indicators, calibration traceability and operator considerations. The standard recommends bringing parts and equipment to 20 °C before measurement (see ISO 1).
- Accuracy guidance: A suggested maximum total measuring inaccuracy of 10% of the actual tolerance zone for practical inspections.
- Arbors and fixturing: Precision arbors are required for runout and bore measurements; typical rotational accuracy/taper recommendations are included to allow correction for arbor errors.
- Measuring force and stylus: The standard requires minimizing measuring force to prevent distortion of thin rings and provides tables for maximum measuring force and minimum stylus radius to ensure repeatable results.
- Coaxial measuring loads: Recommended coaxial loads are given for different bearing types (radial ball, tapered roller, angular contact and thrust bearings) to maintain correct assembly relationships during measurement.
- Measurement zone and preparation: Defines radial measurement zones and advises removal of grease/seals when these affect results; the reference face for measurements is designated by the manufacturer.
- Format and limits: Detailed methods for specific features are presented (clauses 7–16); Annex A cross-references clauses to ISO 1132-1 definitions.
Applications - who uses ISO 1132-2?
- Bearing manufacturers and component suppliers for quality control and production inspection.
- Metrology and testing laboratories performing dimensional and geometric verification of bearings.
- Design, QA and procurement engineers in automotive, aerospace, rail, heavy machinery and industrial equipment specifying bearing tolerances and acceptance criteria.
- Dispute resolution and contract specification when interpreting bearing tolerance measurement results.
Related standards
Key normative references within ISO 1132-2 include:
- ISO 1132-1 (Terms and definitions)
- ISO 1 (Reference temperature)
- ISO 4291 (Roundness measurement)
- ISO 5593 (Rolling bearings vocabulary)
- ISO 15241 (Symbols for quantities)
Other referenced bearing standards and limits of fit tables are also cited.
Keywords: ISO 1132-2, rolling bearings tolerances, measuring and gauging principles, bearing measurement methods, bore diameter measurement, radial runout, radial clearance, bearing metrology.
