684
600 Series Miniature Bearings
Image may differ from product. See technical specification for details.
Part No.
Part No.
684
Basic Information
Bearing type
Ball
System of measurement
Metric
Construction
Single Row
Weight
0.65 g
Tolerance class
ABEC1
Seal type
Open
For load direction
Radial
Main Dimensions
Bore diameter
4 mm
Bore diameter tolerance
-0.008mm to 0
Outside diameter
9 mm
Outside diameter tolerance
-0.008mm to 0
Width
2.5 mm
Width tolerance
-0.12mm to 0
Inner Ring Dimensions
Inner ring type
Standard
Ball & Washer Dimensions
Ball diameter
1.588 mm
Ball quantity
7
Performance
Temperature range
-30° to 110 °C
Radial dynamic load rating
123 lbf
Radial static load rating
41 lbf
Limiting speed
53 X 1000 rpm
Lubrication
Required
Radial internal clearance
MC3
Radial internal clearance
0.002mm to 0.013mm
Materials
Ring material
Chrome Steel
Ball material
Chrome Steel
Cage material
Stainless Steel
Environment & Compliance
REACH
Compliant
ROHS
Compliant
Technical Drawings
No drawings available at the moment, will be launched soon
Price:
$ 1.13
/ each
In Stock
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684 Bearing Product Overview & Core Advantages
The 684 metric ball bearing is a single row deep groove ball bearing engineered for high-performance in compact spaces. Designed primarily for radial load applications, it offers reliable operation and is manufactured to ABEC1 precision class tolerances. Its open design allows for versatile lubrication options to suit specific operational needs, making it an ideal choice for applications demanding a balance of high limiting speed and compact dimensions.
684 Bearing Model Code Explained, Specifications & Naming Convention
| Prefix/Suffix | Interpretation |
|---|---|
| 684 | Basic model number denoting a metric, single row deep groove ball bearing with a 4mm bore, 9mm OD, and 2.5mm width. |
| Open | No seals or shields, allowing for high-speed operation and custom re-lubrication. |
| MC3 | Specifies a greater than normal radial internal clearance (0.002mm to 0.013mm), suitable for applications with thermal expansion concerns or where interference fits are used. |
684 Bearing Structural Features & Performance Benefits
- Optimized Load Capacity: The deep groove raceway and 7 high-grade chrome steel balls provide excellent radial dynamic load rating of 123 lbf, handling significant radial forces despite its miniature size.
- High-Speed Capability: The stainless steel cage ensures ball stability and low friction, contributing to a high limiting speed of 53,000 rpm.
- Precision & Reliability: Manufactured to ABEC1 tolerance class with tight dimensional control on bore, OD, and width, ensuring consistent performance and ease of installation.
- Material Integrity: Rings and balls made from chrome steel offer high hardness and wear resistance, while the stainless steel cage provides corrosion resistance and durability.
- Versatile Operating Range: A temperature range of -30°C to 110°C allows for use in various environmental conditions.
684 Bearing Typical Application Areas
This miniature deep groove ball bearing is ideally suited for applications requiring compact size, high speed, and reliable radial load support.
- Small Precision Motors (e.g., in drones, RC models, small fans)
- Medical and Dental Handpieces
- Office Automation Equipment (e.g., printers, scanners)
- Instrumentation and Control Devices
- Textile Machinery guides and tensioners
