MR31
MR Series Miniature Bearings
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Part No.
Part No.
MR31
Basic Information
Bearing type
Ball
System of measurement
Metric
Construction
Single Row
Weight
0.04 g
Tolerance class
ABEC1
Seal type
Open
For load direction
Radial
Main Dimensions
Bore diameter
1 mm
Bore diameter tolerance
-0.008mm to 0
Outside diameter
3 mm
Outside diameter tolerance
-0.008mm to 0
Width
1.5 mm
Width tolerance
-0.12mm to 0
Inner Ring Dimensions
Inner ring type
Standard
Ball & Washer Dimensions
Ball diameter
0.6 mm
Ball quantity
6
Performance
Temperature range
-30° to 110 °C
Radial dynamic load rating
22 lbf
Radial static load rating
6 lbf
Limiting speed
117 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:
$ 15.68
/ each
In Stock
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MR31 Bearing Product Overview & Core Advantages
The MR31 metric ball bearing is a precision single row deep groove ball bearing engineered for applications demanding compact size and reliable performance. Designed primarily for radial loads, it features an open design requiring lubrication for operation. Its miniature dimensions (1mm bore, 3mm OD) and ABEC1 precision class make it an ideal component for high-speed, compact mechanisms where space is at a premium and consistent operation is critical.
MR31 Bearing Model Code Explained, Specifications & Naming Convention
| Model Segment | Interpretation | Technical Significance |
|---|---|---|
| MR31 | Base Model Number | Defines the core bearing dimensions: 1mm bore, 3mm outside diameter, 1.5mm width. |
| Open (No Seal Suffix) | Seal Type | No integral seals or shields. Allows for higher limiting speeds but requires external lubrication and protection from contaminants. |
| N/A (Implied) | Cage & Clearance | Features a stainless steel cage and MC3 radial internal clearance (0.002mm to 0.013mm) suitable for a wide range of operational conditions. |
MR31 Bearing Structural Features & Performance Benefits
- High-Speed Capability: The combination of an open design, a lightweight stainless steel cage, and precision grinding enables a high limiting speed of 117,000 rpm, making it suitable for very fast-rotating applications.
- Robust Construction: Manufactured from chrome steel for both rings and balls, this bearing offers excellent wear resistance and durability under radial dynamic and static loads (22 lbf and 6 lbf respectively).
- Precision Performance: Built to ABEC1 tolerance class, it ensures smooth and quiet running, minimizing vibration and contributing to the overall accuracy of the assembly.
- Versatile Operating Range: With a temperature range from -30°C to 110°C, it performs reliably in various environments. Its MC3 internal clearance provides optimal performance considering fit and thermal expansion.
MR31 Bearing Typical Application Areas
This miniature deep groove ball bearing is specifically designed for ultra-compact and high-speed devices, including:
- Small Precision Motors and stepper motors
- Medical and Dental Handpieces
- Miniature Gearboxes and drive systems
- Optical Encoders and Precision Instruments
- Small Drones and RC Models
- Office Automation Equipment (e.g., small printers, scanners)
