Superfinishing Machine

Selection criteria

Stone oscillation, pressure control, achievable roughness.

Supply chain

Superfinishing is led by German specialists (Thielenhaus, Supfina), with Chinese makers supplying many bearing plants. Raceway roughness and waviness achieved here directly drive motor noise, so low-noise motors usually need premium-grade bearings.

Buyer FAQ

What surface roughness does raceway superfinishing achieve?

Ground raceways are typically around Ra 0.2–0.4 µm; superfinishing brings them down to about Ra 0.02–0.08 µm. It also removes the thin damaged layer from grinding and reduces short-wave waviness, which matters more for noise than roughness alone.

Which process settings matter on a superfinishing machine?

The key settings are stone oscillation frequency and amplitude (typically tens of hertz and a few millimetres), stone contact pressure, workpiece speed and cycle time. Fine aluminium-oxide or silicon-carbide stones are standard, and low-noise bearings usually get a two-stage rough-and-fine cycle. Stable pressure control and stone dressing determine consistency.

How does superfinishing affect motor noise, and how is it verified?

Residual raceway waviness excites vibration at discrete frequencies that the motor housing can amplify into audible tones. Verify with waviness measurement on a roundness instrument and with bearing vibration tests in the low, medium and high bands of ISO 15242. For quiet motors, specify Z3/V3 or better bearings.

Where it is used