MR166ZZ / MR166-2ZC3 / MR166Z Deep Groove Ball Bearings with Metal Shields , 6*16*5mm

MR166Z, MR166ZZ and MR166-2ZC3 belong to the same miniature deep groove ball bearing series with unified mounting dimension 6×16×5mm, distinguished only by sealing structure and internal clearance suffix codes.

• MR166Z: Single side stamped metal dust shield (single Z)
• MR166ZZ: Double sides stamped non-contact metal dust shields (double ZZ), standard CN normal clearance
• MR166-2ZC3: Double metal ZZ shields + upgraded C3 enlarged radial clearance for high-temperature high-speed shafts

Adopt non-contact thin steel shield design with ultra-low rotational friction torque, excellent heat dissipation performance compared with rubber sealed bearings. Mirror superfinished raceway and precision steel balls support stable ultra-high-speed continuous rotation under light radial loads. The C3 clearance variant compensates thermal expansion of miniature motor spindles, avoiding bearing seizure after long-hour operation. Widely used for 3D printer extruder shafts, RC drone micro drive motors, small cooling fans, medical testing instruments, model aircraft and miniature automation transmission assemblies.

Complete CAD dimension drawings and micro equipment fitment list can be provided upon request

• Three model variants share identical 6×16×5mm installation size, only differ in shield quantity and clearance grade, meet different dust-proof and high-speed heat expansion demands in one product series.
• Non-contact metal ZZ dust shield structure creates tiny gap between shield and inner ring, greatly reduce rotation friction loss, guarantee superior heat dissipation for long-time high-speed micro motor operation.
• Upgraded MR166-2ZC3 C3 enlarged clearance design offsets thermal expansion of tiny high-speed spindles, effectively eliminate bearing locking and rotation lag caused by temperature rise.
• Ultra-smooth mirror superfinished inner/outer raceway and precision steel ball surface cut vibration and noise drastically, maintain silent stable running for precision testing instruments and RC model equipment.
• Lightweight thin-wall miniature structure occupies minimal installation space, ideal for compact narrow-shaft micro equipment with strict volume limits.
• Stable quenching & tempering heat treatment for GCr15 steel provides outstanding anti-fatigue performance, withstand frequent start-stop alternating light loads of miniature motors.
• Support customized clearance grade, high-speed low-viscosity special grease, OEM laser marking and neutral vacuum anti-rust packaging for global miniature machinery spare parts distributors.

This MR166 6×16×5mm miniature metal shield bearing is widely suitable for:

• 3D printer extruder and guide roller transmission shafts
• RC drone, model aircraft, remote control car micro drive motors
• Notebook cooling fans, small blower ventilation miniature rotary parts
• Medical analytical testing instruments, optical precision measuring equipment
• Miniature gear reducers, small stepping motors, beauty equipment micro rotating shafts
• Equipment repair shops and global micro industrial spare parts wholesale suppliers

Model selection guidance:

• MR166Z: Clean dry equipment only needing unilateral dust isolation
• MR166ZZ: General indoor workshop with light dust, normal speed micro motors
• MR166-2ZC3: Long-running high-speed miniature spindles prone to temperature rise

Ideal compact replacement bearing for overhaul of high-speed light-load miniature precision equipment

• Over 25 years professional manufacturing experience of MR series miniature deep groove ball bearings
• Strictly comply with international miniature bearing dimensional tolerance standards, 100% interchangeable with original MR166Z / MR166ZZ / MR166-2ZC3 bearings
• Complete production workflow covering steel forging, heat treatment, precision raceway grinding and finished noise & ultra-high-speed durability testing
• Sufficient spot stock for 6×16×5mm MR166 series three variants, fast shipment for bulk micro equipment spare parts orders
• Professional engineering team provides miniature shaft press-fit installation guidance and clearance grade selection suggestions
• Products exported to more than 50 countries, stable long-term supply for precision electronics and model equipment aftermarket suppliers

1. Raw bearing steel chemical composition and hardness inspection before processing
2. CNC inner/outer ring turning, raceway precision grinding and mirror superfinishing procedure
3. Constant temperature quenching & tempering heat treatment to stabilize internal material stress
4. Full finished product testing: internal clearance, rotation noise, rotational flexibility, ultra-high-speed endurance and light alternating load fatigue test
5. Full dimensional tolerance inspection for inner ring, outer ring and width plus visual appearance scratch check
6. Anti-rust oil coating + independent vacuum packaging to avoid rust during long-distance sea transportation

Every batch of MR166 miniature bearings passes full inspection before shipment to guarantee stable precision micro equipment operation

Looking for wholesale MR166Z, MR166ZZ and MR166-2ZC3 miniature metal shield bearings 6×16×5mm?
Send your inquiry to obtain:

• Competitive factory direct bulk unit price for single Z, double ZZ and C3 clearance versions
• Complete 3D printer / drone / micro motor equipment fitment checklist
• Custom clearance grade, high-speed special grease and OEM laser marking packaging solutions
• Technical support for miniature shaft bearing press-fit installation and high-speed noise troubleshooting

Detailed dimension catalog and real-time stock availability can be checked upon contact