Roundness Tester – Bearing Measurements

What is a Roundness Tester

The roundness tester is a measuring instrument used to verify the roundness (or circularity) of cylindrical or spherical surfaces, such as those of bearings, shafts or bushings.

How We Guarantee the Precision of Our Rolling Bearings

• In the case of rolling bearings, the roundness tester can measure:
• the roundness of inner and outer raceways,
• the concentricity between raceways and reference diameters,
• the eccentricity,
• any periodic waves (lobing), related to machining defects
• flatness of flat surfaces of the component
• parallelism
• perpendicularity

The component is mounted on a high-precision rotating spindle, and a stylus records radial deviations during rotation. The collected data are processed and displayed in the form of a polar or Cartesian graph.
 

Parameters such as maximum roundness deviation (RONt), waveform, and dominant harmonics are obtained, useful for evaluating geometric conformity according to ISO specifications.

Parameters such as maximum roundness deviation (RONt), waveform, and dominant harmonics are obtained, useful for evaluating geometric conformity according to ISO specifications.

It is a fundamental tool in bearing quality control, especially in the finishing and testing phases.