The characteristics of ultra-precision cylindrical roller bearings are as follows: • High-speed capability • High radial load capacity • High rigidity • Low friction • Low cross-sectional height Therefore, these bearings are particularly suitable for machine tool spindles where the bearing configuration must withstand heavy radial loads and high speeds while providing high rigidity. Ultra-precision single-row cylindrical roller bearings have better speed performance than double-row bearings, while double-row bearings are more suitable for withstanding heavier loads.