Key Takeaways:
Rolling-bearing spindles wear, drift with heat, and struggle at low speed. Hydrostatic spindles float the shaft on oil for sub-micron runout, no crawl, and infinite life.
The Rolling-Bearing Limit
A conventional spindle supports its shaft on rolling bearings. Those bearings have solid contact friction, a finite service life, and can exhibit stick-slip at low speed. Friction heat also causes thermal growth that degrades accuracy over a shift.

The Hydrostatic Spindle
A hydrostatic spindle replaces rolling contact with a 3–50 μm oil film. The shaft floats non-contact, so there is no wear, no low-speed crawl, and no friction heat. Radial runout sits at or below 0.1 μm with oil-film stiffness above 500 N/μm.
Bottom Line
For mirror-finish grinding and tight-tolerance turning, the hydrostatic spindle removes the error sources that cap a rolling-bearing design—delivering repeatable, thermally stable precision.