Miniature ball bearings refer to small ball bearings with bore diameters under 10mm. Despite their micro dimensions, they are engineered to maintain high geometrical accuracy, low noise thresholds, and extreme speed tolerances.
These bearings are widely deployed in medical tooling, dental drill handpieces, precision robotics, small motors, high-frequency spindles, instrumentation, and office automation gear. We supply these micro components in stainless steel (SUS440C) for corrosive environments, or chrome steel for standard operations.
Standard dimensional parameters for micro and miniature deep groove series.
| Bearing Model | Bore (d) | Outer Dia (D) | Width (B) | Dynamic Load (Cr) | Static Load (Cor) | Limiting Speed (Grease) | Material Options |
|---|---|---|---|---|---|---|---|
| MR52 ZZ | 2.0 mm | 5.0 mm | 2.5 mm | 0.17 kN | 0.05 kN | 50,000 RPM | Chrome / Stainless |
| MR63 ZZ | 3.0 mm | 6.0 mm | 2.5 mm | 0.21 kN | 0.07 kN | 45,000 RPM | Chrome / Stainless |
| MR84 ZZ | 4.0 mm | 8.0 mm | 3.0 mm | 0.39 kN | 0.14 kN | 40,000 RPM | Chrome / Stainless |
| 682 XZZ | 2.5 mm | 6.0 mm | 2.6 mm | 0.25 kN | 0.08 kN | 42,000 RPM | Chrome / Stainless |
| 683 ZZ | 3.0 mm | 7.0 mm | 3.0 mm | 0.39 kN | 0.13 kN | 38,000 RPM | Chrome / Stainless |
| 684 ZZ | 4.0 mm | 9.0 mm | 4.0 mm | 0.64 kN | 0.22 kN | 35,000 RPM | Chrome / Stainless |
| 688 2RS / ZZ | 8.0 mm | 16.0 mm | 5.0 mm | 1.60 kN | 0.71 kN | 28,000 RPM | Chrome / Stainless |
| 693 ZZ | 3.0 mm | 8.0 mm | 4.0 mm | 0.56 kN | 0.18 kN | 35,000 RPM | Chrome / Stainless |
* Shield configurations include Open, Metal Shield (ZZ), and Rubber Sealed (2RS / RS).
Understanding the technical suffixes, clearance prefixes, and material ratings used in industrial procurement.
Critical engineering parameters, structure details, and operating limits to help you select the ideal component.
Designed specifically for ultra-precise micro-applications with bore sizes ranging from 1mm to 9mm. Made from high-grade SUS440C stainless steel for anti-corrosion resistance or SAE 52100 chrome steel for standard loads.
Conforms to Z3/V3 low-vibration grades, ensuring silent operation and low frictional drag. Shielded (ZZ) or sealed (2RS) layouts prevent grease leakage and particle ingress in precision components.
Extensively used in high-precision dental drills, surgical tools, micro-motors, optical encoders, miniature robotics, and high-spec RC models requiring reliable high-RPM limits.
These bearings are engineered to deliver reliable rotation and support critical equipment in harsh sectors, including:
Provides ultra-high-speed rotation (up to 40,000 RPM) inside surgical drills and dental handpieces.
Enables tiny rotational movements inside servo actuators, gimbal joints, and robotic hands.
Secures quiet, long-life operations inside computer cooling fans and electronics enclosures.
Supports precision transmission inside hobby RC motors and micro-positioning instruments.
Technical details, selection parameters, and service queries resolved by our engineering sales team.
