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R Series
Home Deep Groove Ball Bearings R Series

R166-ZZ Double Shielded Miniature Ball Bearing | Dust-Proof Precision | 4.762 × 9.525 × 3.175 mm

R166-ZZ Double Shielded Miniature Ball Bearing | Dust-Proof Precision | 4.762 × 9.525 × 3.175 mm

The R166-ZZ is a highly versatile inch-series miniature ball bearing designed for environments where both reliable rotation and protection from airborne debris are critical. By utilizing a double-shielded ("ZZ") configuration, this bearing effectively locks in factory-applied grease while blocking dust, dirt, and fine particulate matter from entering the raceways. With its standard 3/16-inch bore, the R166-ZZ is an essential, maintenance-free component for compact electric motors, hobbyist models, and precision commercial equipment requiring sustained, smooth performance without regular relubrication.

R166-ZZ Deep Groove Ball Bearing 4.762 × 9.525 × 3.175 mm | R Series – Extended Lifespan & Contaminant Resistance

Engineered for longevity and stable mechanics, the enclosed architecture of the R166-ZZ makes it highly resistant to harsh operating conditions. The non-contact metal shields sit flush within the outer ring, maintaining an optimal balance: they provide excellent barrier protection without adding the heavy rotational drag associated with rubber seals. Whether installed in automated office equipment or a heavy-duty RC vehicle, this bearing delivers quiet, efficient power transmission and reduces equipment downtime by protecting the internal rolling elements from premature wear.

R166-ZZ Double Shielded Miniature Ball Bearing | Dust-Proof Precision | 4.762 × 9.525 × 3.175 mm

Comprehensive Applications

Highly recommended for mechanical engineers and technicians looking for dependable, shielded performance in 3/16-inch shaft applications:

Hobby & RC Equipment
  • Radio-Controlled (RC) Cars and Helicopters
  • Slot Car Motor Assemblies
  • Model Train Drivetrains
  • Drone Gimbal Mechanisms
Office & Automation Machinery
  • High-Volume Commercial Printers
  • Automated Sorting Spindles
  • Currency Counting Machines
  • Precision Stepper Motors
Medical & Scientific Devices
  • Handheld Dental Tools
  • Diagnostic Centrifuges
  • Automated Fluid Pumps
  • Laboratory Dial Indicators

Key Performance Features

01. Dual Metal Shielding (ZZ)

A core advantage of the R166-ZZ is its twin pressed-steel shields. These enclosures securely retain the internal lubricant while deflecting external debris. Because the shields do not make physical contact with the inner ring, the bearing still achieves exceptional high-speed capabilities while remaining fully maintenance-free throughout its operational life.

02. Standardized Imperial Footprint

Measuring exactly 4.762 mm (3/16") at the bore and 9.525 mm (3/8") across the outer diameter, this bearing provides drop-in compatibility for standard inch-based mechanical assemblies. Its narrow 3.175 mm (1/8") width allows for efficient stacking or placement in severely space-restricted housings.

03. High-Carbon GCr15 Chrome Steel

Manufactured from strictly graded GCr15 Chrome Steel (SAE 52100), the inner and outer rings, as well as the ball elements, deliver P5-grade dimensional accuracy. This extensive heat-treatment process guarantees excellent load-bearing capacity, high surface hardness, and superior resistance against metal fatigue during continuous cycling.

Technical Specifications

Bearing Type Single Row Deep Groove Ball Bearing
ISO Dimension Series R Series (Miniature Imperial / Inch)
Basic Designation R166
Suffix Options ZZ (Dual Metal Shields)
Bore Diameter (d) 4.762 mm (3/16")
Outer Diameter (D) 9.525 mm (3/8")
Width (B) 3.175 mm (1/8")
Material (Races & Balls) Chrome Steel (GCr15 / SAE 52100) or Stainless Steel (AISI 440C)
Precision Class Standard / P5 Grade Available
Cage Material Pressed Steel (ribbon type) or Polyamide
Dynamic Load Rating (Cʳ) 0.713 kN (713 N)
Static Load Rating (C₀ʳ) 0.273 kN (273 N)
Limiting Speed (Grease) 40,000 r/min
Limiting Speed (Oil) -
Weight (approx.) 0.0008 kg (0.8 grams)

Interchange Part Numbers

Cross-reference equivalents to streamline your purchasing process:

  • NMB: R-1030ZZ
  • SKF: R166-2Z
  • FAG: R166-2Z
  • NSK: R166ZZ
  • NTN: R166ZZ
  • Barden: R166SS
  • KOYO: R166ZZ

Design & Configuration

For over 15 years, Welink Bearing has delivered precise rotational solutions to global manufacturing sectors. The R166-ZZ represents our commitment to durability in compact forms. All our double-shielded miniature bearings arrive factory-lubricated with premium lithium-based grease, fully ready for immediate installation. We also provide customized lubricant fills (from wide-temperature greases to low-noise synthetic variants) to perfectly match your specific motor or application requirements.

"Secure your micro-mechanisms with the R166-ZZ bearing—delivering shielded durability, standard inch precision, and maintenance-free reliability for demanding applications.”

Download Product Catalog (PDF)

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Details

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