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67 Series
Home Deep Groove Ball Bearings 67 Series

6702 Open Type Thin Section Ball Bearing | Unshielded Metric Micro Bearing | 15×21×4 mm

6702 Open Type Thin Section Ball Bearing | Unshielded Metric Micro Bearing | 15×21×4 mm

The 6702 is a high-precision open-type thin-section bearing designed for advanced mechanical systems that prioritize ultra-low starting torque and unrestricted lubrication access. By omitting integrated seals or shields, this model achieves the lowest possible rotational friction, making it an ideal candidate for high-speed oil-bath environments and sensitive measuring instruments. With a 15mm bore and a slim 4mm profile, the 6702 serves as a critical rotational support for hollow-shaft encoders, robotic joints, and aerospace-grade telemetry systems.

6702 Deep Groove Ball Bearing 15x21x4 mm | Extra Light Metric Series | Unshielded for Low Torque

Engineered for seamless integration into high-performance assemblies, the 6702 is manufactured from high-purity GCr15 chrome steel. Its open architecture allows for direct visual inspection of the internal raceways and enables external lubrication systems such as oil mist or circulation, to interact directly with the rolling elements. This ensures optimal heat dissipation and consistent performance during continuous high-RPM operation. The extra-light series geometry provides a significant weight advantage for designers looking to maximize the payload capacity of drones, portable medical devices, and precision optical platforms.

6702 Open Type Thin Section Ball Bearing | Unshielded Metric Micro Bearing | 15×21×4 mm

Comprehensive Applications

The 6702 Open Bearing is the professional solution for clean-environment systems requiring absolute rotational transparency:

Precision Robotics & Automation
  • Articulated robotic arm wrist joints
  • High-resolution rotary shaft encoders
  • Low-friction mechatronic drive units
Optical & Imaging Technology
  • Motorized laser scanning modules
  • High-frequency camera focus actuators
  • Precision gimbal stabilization axes
Scientific & Laboratory Instrumentation
  • Miniature fluid centrifuge systems
  • High-accuracy analytical balances
  • Vacuum-compatible scientific sensors
Aerospace & UAV Engineering
  • Lightweight telemetry housing supports
  • Specialized micro-actuator assemblies
  • High-speed motor test stands

Key Performance Features

01. Zero-Drag Mechanical Architecture

The defining advantage of the 6702 Open Type is the absence of seal-to-ring contact. This creates a "zero-drag" environment, which is essential for battery-powered or solar-powered devices where energy efficiency and minimal mechanical resistance are paramount.

02. Enhanced Thermal Dissipation

In high-speed applications, heat build-up can compromise bearing life. The open configuration allows lubricant to flow freely across the raceways, effectively carrying away thermal energy. This makes the 6702 particularly effective in systems with integrated oil-cooling or circulation.

03. Large Bore / Ultra-Thin Profile Efficiency

The 15mm bore diameter allows for larger internal wiring, shafts, or optical paths to pass through the center of the bearing. Despite this large capacity, the 21mm outer diameter ensures the overall assembly remains incredibly compact, meeting the demands of modern miniaturized hardware.

Technical Specifications

Bearing Type Single Row Deep Groove Ball Bearing
ISO Dimension Series 67 Series (Thin Section / Extra Light)
Basic Designation 6702
Suffix N/A (Open Type)
Bore Diameter (d) 15 mm
Outer Diameter (D) 21 mm
Width (B) 4 mm
Material (Races & Balls) Chrome Steel (GCr15 / SAE 52100)
Precision Class Standard / P5 Grade Available
Cage Material Pressed Steel
Dynamic Load Rating (Cʳ) 0.95 kN
Static Load Rating (C₀ʳ) 0.58 kN
Limiting Speed (Grease) 36,000 r/min
Limiting Speed (Oil) --
Weight (approx.) 0.0033 kg

Interchange Part Numbers

Compatible with international thin-section open bearing standards:

  • SKF: 61702
  • NSK: 6702
  • FAG61702
  • NTN: 6702
  • KOYO: 6702
  • NMB: 6702

Design & Configuration

The 6702 Open Bearing is provided with a protective coating of light anti-rust oil. It is designed to be lubricated on-site with a specific grease or oil tailored to the application's unique speed and temperature requirements. For environments where the bearing will be exposed to dust, moisture, or particulate matter, we recommend the 6702-ZZ (shielded) or 6702-2RS (sealed) versions for improved longevity.

"Engineered for frictionless high-speed operation, the 6702 Open Type delivers the ultimate in rotational accuracy and space-saving efficiency."

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