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67 Series
Home Deep Groove Ball Bearings 67 Series

6708-2RS Ultra-Thin Section Sealed Ball Bearing For Medical Devices & Precision Actuators | 40×50×6 mm

6708-2RS Ultra-Thin Section Sealed Ball Bearing For Medical Devices & Precision Actuators | 40×50×6 mm

The 6708-2RS is an ultra-thin section deep groove ball bearing engineered for applications demanding complete contaminant exclusion within severely limited axial space. Featuring dual contact rubber seals (2RS), this configuration provides superior protection against fine dust, moisture, and fluid ingress while maintaining permanent grease retention for truly maintenance-free operation. With a 40mm bore, 50mm outer diameter, and an exceptionally slim 6mm cross-section, it serves as a critical component for medical diagnostic equipment, laboratory instruments, and compact linear actuators where reliability cannot be compromised by environmental exposure.

6708-2RS Deep Groove Ball Bearing 40x50x6 mm | Metric Ultra-Thin Section | Double Sealed

Manufactured to strict ISO dimensional and running accuracy standards, the 6708-2RS combines a minimal 6mm cross-section with full deep groove ball bearing functionality. The contact rubber seals create a positive barrier against external contaminants while retaining the factory-applied grease, making this bearing suitable for environments where shielded variants would be insufficient. Despite its slim profile, the deep raceway geometry accommodates moderate radial and bidirectional axial loads with consistent rotational smoothness.

 

6708-2RS Ultra-Thin Section Sealed Ball Bearing For Medical Devices & Precision Actuators | 40×50×6 mm

Comprehensive Applications

Well-suited for precision equipment operating in challenging or sensitive environments:

Medical & Diagnostic Equipment
  • Automated clinical analyzer sample transport systems
  • Medical infusion pump roller assemblies
  • Diagnostic imaging system positioning stages
  • Dental x-ray unit rotating arms
Laboratory & Analytical Instruments
  • Centrifuge rotor support bearings
  • Laboratory shaker and mixer drives
  • Spectrometer optical bench positioning
  • Liquid handling robot joint mechanisms
Precision Consumer & Office Devices
  • High-end office copier drum support
  • Professional printer paper transport rollers
  • Scanner carriage guide bearings
  • Compact drone gimbal assemblies
Industrial Automation
  • Compact linear actuator guide rollers
  • Pick-and-place end effector rotary joints
  • Light-duty conveyor roller supports
  • Small diameter tensioning pulleys

Key Performance Features

01. Superior Contaminant Exclusion

The 2RS designation indicates dual contact rubber seals molded from oil-resistant nitrile rubber (NBR). Unlike metal shields which rely on a narrow gap, these seals maintain continuous light contact with the inner ring, forming a reliable barrier against fine particulates, liquid splashes, and airborne moisture. This sealing configuration ensures lubricant integrity over extended operational periods in environments where cleanliness cannot be guaranteed.

02. Ultra-Thin Section for Compact Integration

With a cross-section measuring just 6mm, the 6708-2RS enables engineers to achieve rotary support in assemblies where conventional bearings would exceed available space. Despite its minimal height, the bearing delivers robust load capacity through optimized internal geometry and precision-ground raceways, making it an essential component for modern miniaturized equipment designs.

03. Precision Manufacturing for Sensitive Applications

Constructed from vacuum-degassed chrome steel (GCr15 / SAE 52100), the 6708-2RS undergoes precision grinding to achieve tight dimensional and geometrical tolerances. The use of high-grade balls and carefully controlled internal clearance ensures smooth, quiet rotation suitable for noise-sensitive medical and laboratory environments. Low-vibration variants are available for applications requiring ultra-smooth operation.

Technical Specifications

Bearing Type Single Row Deep Groove Ball Bearing
ISO Dimension Series 6700 Series (Ultra-Thin Section)
Basic Designation 6708
Suffix 2RS (Double Contact Rubber Seals)
Bore Diameter (d) 40 mm
Outer Diameter (D) 50 mm
Width (B) 6 mm
Material (Races & Balls) Chrome Steel (GCr15 / SAE 52100)
Precision Class Standard / P5 Grade Available
Material (Races & Balls) Nitrile Rubber (NBR) with Steel Insert
Dynamic Load Rating (Cʳ) 4.5 kN
Static Load Rating (C₀ʳ) 4.0 kN
Limiting Speed (Grease) 8,000 - 10,000 r/min
Limiting Speed (Oil) --
Weight (approx.) 0.02 kg

Interchange Part Numbers

Direct replacement for industry-standard bearings:

  • SKF: 6708-2RS1
  • NSK: 6708VV
  • FAG6708-2RSR
  • NTN: 6708LLU
  • KOYO: 6708-2RS
  • TIMKEN: 6708-2RS

Design & Configuration

The 6708-2RS is factory-filled with high-quality lithium-based grease suitable for a wide temperature range and sealed with double contact rubber seals. This configuration prioritizes environmental protection over maximum speed capability, making it ideal for applications exposed to dust, moisture, or periodic cleaning. For applications requiring higher rotational speeds with reduced frictional torque, a shielded (ZZ) variant is recommended. Stainless steel (AISI 440C) versions are available for corrosive environments, and C3 clearance options accommodate assemblies with significant thermal expansion.

"Engineered for the rigorous demands of medical diagnostics and precision automation, the 6708-2RS delivers reliable sealing and smooth rotation within an ultra-thin envelope that maximizes design flexibility."

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