71921 ACD/P4A
71900 Series Super Precision Angular Contact Ball Bearings
Image may differ from product. See technical specification for details.
Part No.
Part No.
71921 ACD/P4A
Basic Information
System of measurement
Metric
Weight
0.82 kg
Tolerance class
P4 (ABEC-7)
Seal type
Open
For load direction
Angular Contact
Main Dimensions
Bore diameter
105 mm
Bore diameter tolerance
-0.008mm to 0
Outside diameter
145 mm
Outside diameter tolerance
-0.009mm to 0
Width
20 mm
Width tolerance
-0.2mm to 0
Contact angle
25 °
Ball & Washer Dimensions
Ball diameter
12.7 mm
Ball quantity
27
Performance
Temperature range
-30° to 110 °C
Radial dynamic load rating
12870 lbf
Radial static load rating
14738 lbf
Limiting speed
12 X 1000 rpm
Lubrication
Lubricated
Matched arrangement
Single
Preload
Available
Materials
Ring material
Chrome Steel
Ball material
Chrome Steel
Cage material
Phenolic
Technical Drawings
No drawings available at the moment, will be launched soon
Price:
$ 1417.81
/ each
In Stock
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71921 ACD/P4A Bearing Product Overview & Core Advantages
The 71921 ACD/P4A is a single-row angular contact ball bearing engineered for high-precision applications requiring exceptional rotational accuracy and rigidity. This metric bearing features a 25° contact angle and is supplied with a P4 (ABEC-7) tolerance class, making it ideal for machine tool spindles and other high-speed equipment. Its key advantage lies in its ability to accommodate combined loads (simultaneous radial and axial loads) efficiently. The phenolic cage and preloaded configuration contribute to superior high-speed performance and operational stability.
Model Code Breakdown
| Suffix Code | Technical Meaning |
|---|---|
| ACD | Optimized internal design with a 25° contact angle for high axial load capacity and rigidity. |
| P4 | Indicates a high-precision tolerance class (equivalent to ABEC-7), ensuring minimal runout and vibration. |
| A | Signifies that the bearing is supplied with a specific preload for enhanced stiffness and precise shaft positioning. |
71921 ACD/P4A Bearing Structural Features & Performance Benefits
- High Rigidity & Precision: The single-row angular contact design with a 25° contact angle and P4 precision provides excellent rigidity and running accuracy, critical for applications like machine tool spindles.
- Superior Load Capacity: Engineered to handle significant combined radial and axial loads in one direction, making it suitable for demanding operational conditions.
- Optimized High-Speed Performance: The lightweight phenolic resin cage reduces centrifugal forces, enabling a high limiting speed of 12,000 rpm. The bearing is pre-lubricated for immediate operation.
- Durable Construction: Manufactured from chrome steel for both rings and balls, ensuring high durability and a long service life under rigorous operating conditions.
71921 ACD/P4A Bearing Typical Application Areas
This precision angular contact ball bearing is predominantly used in:
- Machine Tool Spindles (High-speed milling, grinding)
- Precision Gearboxes
- High-Frequency Motors
- Medical Equipment (e.g., Dental handpieces)
- Aerospace Actuation Systems
