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63 Series
Home Deep Groove Ball Bearings 63 Series

6308 Premium Deep Groove Ball Bearing For Industrial Machinery & Electric Motors | 40x90x23 mm

6308 Premium Deep Groove Ball Bearing For Industrial Machinery & Electric Motors | 40x90x23 mm

The 6308 is a Premium Single Row Deep Groove Ball Bearing engineered for medium-to-heavy duty applications requiring reliable performance and extended service life. This metric bearing features an open design, allowing for flexible lubrication options and easy integration into various housing configurations. With a 40mm bore, 90mm outer diameter, and 23mm width, it is ideal for electric motors, pumps, gearboxes, industrial fans, and automotive components where robust construction and high load capacity are essential.

6308 Deep Groove Ball Bearing 40x90x23 mm | ISO 63 Series – Medium Duty | Open Type

Premium precision bearing featuring the universal deep groove geometry. Engineered for smooth, high‑speed operation up to 7,700 r/min (Grease) and 9,200 r/min (Oil). The 6308 is capable of supporting moderate to heavy radial loads and light axial loads in both directions, making it a versatile component for industrial machinery, agricultural equipment, material handling systems, and power transmission applications .

6308 Premium Deep Groove Ball Bearing For Industrial Machinery & Electric Motors | 40x90x23 mm

Comprehensive Applications

Ideally suited for a wide range of industrial and automotive uses:

Industrial Machinery
  • Machine Tool Drives
  • Agricultural Equipment & Tractors
  • Conveyor Systems & Material Handling
  • Textile Machinery & Spindles
Electric Motors & Drives
  • Centrifugal Pumps & Compressors
  • Gearboxes & Power Transmission Units
  • AC & DC Electric Motors (up to 5.5kW typical)
  • Industrial Fans & Blowers
Automotive & Transportation
  • Two & Three Wheeler Wheel Hubs
  • Light Commercial Vehicle Components 
  • Alternators & Starters
  • Water Pumps
General Engineering
  • Printing & Packaging Machines
  • Industrial Pumps & Valves
  • Construction Equipment
  • Food Processing Machinery

Key Performance Features

01. Robust Construction & High Load Capacity

The 63 series medium-duty design features optimized internal geometry that delivers exceptional radial load capacity while accommodating moderate axial loads. With dynamic load ratings up to 45.5 kN and static load ratings up to 25.0 kN, the 6308 ensures long-term reliability under demanding operating conditions . Manufactured from high-quality chrome steel (GCr15 / SAE 52100), it provides superior wear resistance and fatigue life .

02. High-Speed & Smooth Operation

Manufactured to precision tolerances (PN/ABEC-1 standard, with P5/P6 grades available upon request) . The refined raceway finish, precision balls, and optimized internal clearances (CN/C3 available) deliver exceptionally smooth, quiet, and stable rotation with minimal vibration—perfect for continuous‑duty machinery and sensitive equipment .

03. Versatile Open Design for Flexible Lubrication

The open configuration allows users to select the optimal lubrication method for their specific application—whether grease or oil lubrication. This flexibility makes the 6308 suitable for a wide temperature range (-30°C to +120°C) and various operating environments . For applications requiring contamination protection, sealed or shielded variants (6308-2RS, 6308-ZZ) are also available.

Technical Specifications

Bearing Type Single Row Deep Groove Ball Bearing
ISO Dimension Series 63 Series – Medium Duty
Basic Designation 6308
Suffix ZZ (double shields), 2RS (double rubber seals), Open
Bore Diameter (d) 40 mm
Outer Diameter (D) 90 mm
Width (B) 23 mm
Material (Races & Balls) Chrome Steel (GCr15 / SAE 52100)
Precision Class PN / ABEC-1 Standard (P5/P6 Available)
Cage Material Pressed Steel Ribbon (JN) or Polyamide
Dynamic Load Rating (Cʳ) 40.5 – 50.9 kN
Static Load Rating (C₀ʳ) 24.0 – 25.0 kN
Limiting Speed (Grease) 7,700 – 8,500 r/min
Limiting Speed (Oil) 9,200 – 12,000 r/min
Weight (approx.) 0.61 – 0.65 kg

Interchange Part Numbers

Direct replacement for:

  • SKF: 6308
  • NSK: 6308
  • FAG: 6308
  • NTN: 6308
  • KOYO: 6308
  • Timken: 6308

Design & Configuration

The 6308 open bearing is supplied without seals or shields as standard, allowing maximum flexibility for lubrication and cooling in high-speed applications . For environments requiring protection against contamination, the following variants are available:

• 6308-ZZ: Double metal shields for dust protection while maintaining low friction 

6308-2RS: Double rubber contact seals for enhanced protection against moisture and fine contaminants 

6308-C3: Increased radial internal clearance for applications with interference fits or temperature variations 

6308-ZNR: Shielded bearing with snap ring groove for simplified housing retention 

"For general purpose electric motors, pumps, and industrial gearboxes operating in clean environments, the 6308 open bearing provides optimal performance with customized lubrication."

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