The SKF 639/3-2Z Bearing 3X8X4 is a miniature deep groove ball bearing specifically designed for precision applications. Manufactured by SKF, a leader in bearing technology, this bearing features compact dimensions with a bore diameter of 3 mm, an outer diameter of 8 mm, and a width of 4 mm. Its design is ideal for industries requiring high precision and performance, such as measurement instruments and small electric motors. This bearing is part of the micro bearing category, making it suitable for applications where space is at a premium.
Technical specifications
| Specification | Value |
|---|---|
| Bore diameter (d) | 3 mm |
| Outer diameter (D) | 8 mm |
| Width (B) | 4 mm |
| Weight | 1.2 g |
| Basic dynamic load rating (C) | 0.35 kN |
| Basic static load rating (C0) | 0.13 kN |
| Limiting speed | 100,000 rpm |
| Shielding | ZZ |
| Ring material | Chrome steel 100Cr6 |
| Factory lubrication | Grease |
| Precision class | P0 / ABEC-1 |
| Internal clearance | CN |
Technical advantages
The SKF 639/3-2Z Bearing offers key technical advantages that enhance performance in demanding applications:
- Supports continuous operation up to 100,000 rpm, suitable for high-speed applications.
- Constructed with heat-treated 100Cr6 chrome steel, ensuring a rolling-contact fatigue life exceeding 107 cycles.
- Standard CN radial clearance, optimal for systems requiring minimal play.
- ZZ shielding provides effective protection against contaminants, reducing maintenance needs.
- Grease lubrication ensures smooth operation and reduces friction under typical load conditions.
Typical applications
This miniature deep groove ball bearing is ideal for use in:
- Measurement and laboratory instruments such as optical encoders and electronic micrometers.
- Aeromodelling and drones, specifically in brushless motors and planetary gearboxes.
- Dental equipment, including turbines and micromotors.
- Precision robotics, particularly in harmonic drive reducers and cardan joints.
- Medical devices like peristaltic pumps and lung ventilators.
Availability and ordering
Eurobearing.eu offers the SKF 639/3-2Z Bearing with fast availability, ensuring you have the components you need for your projects. For bulk quantities, you can request a quote to receive competitive pricing. Add the bearing to your cart or contact us for a quotation today.
