MR128-2RS Miniature Deep Groove Ball Bearing | Precision Sealed Micro Bearing | 8×12×3.5 mm
The MR128-2RS is a high-precision miniature ball bearing specifically developed for compact mechanical assemblies where internal clearances are tight and environmental protection is vital. Outfitted with dual contact rubber seals (2RS), this micro-bearing provides a superior barrier against fine dust and moisture while ensuring the internal lubricant remains stable during operation. With an 8mm bore, a 12mm outer diameter, and a slim 3.5mm width, it is the premier choice for RC racing components, small brushless motors, and precision dental tools requiring smooth, dependable rotation.
MR128-2RS Deep Groove Ball Bearing 8x12x3.5 mm | Metric Miniature Series | Dual Rubber Seals
A masterfully engineered rolling element designed for high-speed stability and low-maintenance longevity. The MR128-2RS utilizes a deep groove raceway geometry to accommodate both radial and axial loads in a miniaturized envelope. By employing specialized contact seals, this bearing minimizes internal contamination risks, making it an essential component for high-performance drones, micro-robotics, and office automation hardware where vibration-free performance and silent operation are mandatory.

The MR128-2RS is a versatile solution for a wide range of specialized micro-machinery:
The primary strength of the MR128-2RS is its extremely small footprint. Designed for the most restrictive mechanical designs, it allows for the integration of high-performance rolling elements into spaces where traditional bearings simply cannot fit. This enables the creation of lighter, more efficient handheld devices and micro-robotics.
Equipped with two reinforced nitrile rubber seals, the MR128-2RS is built for durability in "real-world" environments. The contact seals provide a physical interface that blocks out micro-particles and prevents moisture ingress, which is critical for equipment used outdoors, such as RC vehicles or industrial sensors.
Manufactured using high-density GCr15 chrome steel and finished to P5 or P6 precision grades, this bearing ensures minimal audible noise even at high rotational speeds. The refined raceway surfaces reduce friction-induced heat, allowing for sustained high-RPM performance without compromising the integrity of the micro-assembly.
| Bearing Type | Single Row Deep Groove Ball Bearing |
| ISO Dimension Series | MR Series (Metric) |
| Basic Designation | MR128 |
| Suffix | 2RS (Double Contact Rubber Seals) |
| Bore Diameter (d) | 8 mm |
| Outer Diameter (D) | 12 mm |
| Width (B) | 3.5 mm |
| Material (Races & Balls) | Chrome Steel (GCr15 / SAE 52100) |
| Precision Class | Standard (P0) / P6 or P5 Available Upon Request |
| Cage Material | Pressed Steel |
| Dynamic Load Rating (Cʳ) | 0.545 kN |
| Static Load Rating (C₀ʳ) | 0.225 kN |
| Limiting Speed (Grease) | 32,000 r/min |
| Limiting Speed (Oil) | —— |
| Weight (approx.) | 0.0016 kg |
Directly replaces industry-standard miniature bearings:
The MR128-2RS comes pre-lubricated with high-grade synthetic grease, ensuring it is ready for immediate installation. While the rubber seals provide maximum protection, we also offer the MR128-ZZ (metal shields) for applications prioritizing lower torque and slightly higher speeds. For specialized medical or marine use, we provide stainless steel variants (AISI 440C) for enhanced corrosion resistance.
"From the high-speed requirements of racing drones to the precision of medical devices, the MR128-2RS delivers industrial-grade robustness in a micro-sized package."
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Details
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Details
The MR126-ZZ is an Ultra-Compact Double-Shielded Deep Groove Ball Bearing engineered for reliable performance in space-constrained precision applications. Featuring the standard deep groove raceway design, this miniature bearing efficiently handles radial loads and minimal axial loads from both directions. With a 6 mm bore and built-in double metal shields (ZZ), it provides essential protection while maintaining low friction, making it an ideal component for small electric motors, sensitive instruments, micro-drives, and other compact devices where smooth, maintenance-free operation is critical.
Details
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Details
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Details
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Details
The MR128-2RS is a high-precision miniature ball bearing specifically developed for compact mechanical assemblies where internal clearances are tight and environmental protection is vital. Outfitted with dual contact rubber seals (2RS), this micro-bearing provides a superior barrier against fine dust and moisture while ensuring the internal lubricant remains stable during operation. With an 8mm bore, a 12mm outer diameter, and a slim 3.5mm width, it is the premier choice for RC racing components, small brushless motors, and precision dental tools requiring smooth, dependable rotation.
Details
The MR128-ZZ is a precision-engineered miniature ball bearing designed for high-velocity mechanical systems where low starting torque and minimal heat generation are essential. Featuring dual non-contact metal shields (ZZ), this micro-bearing provides reliable protection against larger debris while allowing the internal lubricant to operate at maximum efficiency. With an 8mm bore, a 12mm outer diameter, and a 3.5mm width, it serves as a critical high-performance component for cooling fans, high-frequency micro motors, and precision hobbyist electronics.
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