Roundness Testing
Definition: Roundness testing is the metrological determination of the deviation of a real circular cross-section from the ideal circular form. It assesses compliance with roundness tolerances in accordance with DIN EN ISO 12181. The analysis is carried out by recording profile points and comparing them with a reference geometry.
Practical relevance: Roundness deviations affect the running behaviour, tightness and wear of rotating components such as shafts, bearings or sealing surfaces. The maximum radial deviation within a defined tolerance zone is assessed. Measurements are carried out with roundness measuring instruments or high-precision coordinate measuring machines. Temperature, clamping condition and storage can influence the measurement result.
Decision-making perspectives:
- Technical decision-makers: Ensuring low-vibration rotation and minimal bearing load.
- Purchasing/project management: Clear definition of permissible roundness tolerances in drawings.
- Science: Analysis of manufacturing deviations and form parameters.
- Insurance/law: Verification of geometric deviations in the event of malfunctions.
Typical testing or verification methods: Roundness measuring instrument with rotary table, polar or Cartesian evaluation, comparison with GPS tolerance specifications.
FAQ:
- What is the difference between roundness and cylindricity?
- Roundness refers to a single cross-section, cylindricity to the entire lateral surface of a cylinder.
