71821 ACD/HCP4
Hybrid Ceramic Super Precision Bearings
Image may differ from product. See technical specification for details.
Part No.
Part No.
71821 ACD/HCP4
Basic Information
System of measurement
Metric
Weight
0.29 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
130 mm
Outside diameter tolerance
-0.009mm to 0
Width
13 mm
Width tolerance
-0.2mm to 0
Contact angle
25 °
Ball & Washer Dimensions
Ball diameter
7.144 mm
Ball quantity
35
Performance
Temperature range
-30° to 110 °C
Radial dynamic load rating
4860 lbf
Radial static load rating
6412 lbf
Limiting speed
15 X 1000 rpm
Lubrication
Lubricated
Matched arrangement
Single
Preload
Available
Materials
Ring material
Chrome Steel
Ball material
Ceramic
Cage material
Phenolic
Technical Drawings
No drawings available at the moment, will be launched soon
Price:
$ 1506.14
/ each
In Stock
- Fast delivery
- Free shipping on orders over $200
- Enjoy discounts on bulk purchases
- Secure Payment
- Fast Global Shipping
71821 ACD/HCP4 Bearing Product Overview & Core Advantages
The 71821 ACD/HCP4 is a single-row angular contact ball bearing engineered for applications demanding high precision and high-speed operation. Its defining characteristic is the 25° contact angle, which enables it to support significant combined loads—both radial and axial—in one direction. Manufactured to the exacting P4 (ABEC-7) tolerance class, this bearing delivers exceptional running accuracy and rotational stability. The combination of a ceramic ball material and a phenolic cage contributes to reduced weight, lower friction, and superior performance at high rotational speeds, making it an ideal solution for demanding, precision machinery.
71821 ACD/HCP4 Bearing Model Code Explained, Specifications & Naming Convention
| Model Segment | Code | Technical Meaning |
|---|---|---|
| Basic Designation | 71821 | Indicates a single-row, angular contact ball bearing with a specific internal design and bearing dimensions (105mm bore, 130mm OD, 13mm width). |
| Internal Design | ACD | Signifies a 25° contact angle and that the bearing is optimized for high rigidity and high-speed performance. |
| Tolerance Class | HCP4 | Denotes a P4 (ABEC-7) precision class. The "HC" prefix often indicates a hybrid ceramic design, confirmed by the ceramic balls specified for this model. |
71821 ACD/HCP4 Bearing Structural Features & Performance Benefits
- High-Speed Capability: The use of ceramic (Si3N4) balls significantly reduces centrifugal forces and friction, while the lightweight phenolic resin cage ensures cage integrity and low inertia. This combination enables the high limiting speed of 15,000 rpm.
- High Rigidity & Load Capacity: The 25° contact angle provides excellent resistance to axial loads while maintaining a high radial dynamic load rating of 4860 lbf. This makes the bearing exceptionally rigid and suitable for applications with demanding load conditions.
- Precision Performance: Manufactured to P4 tolerance with strict dimensional and running accuracy controls, this bearing minimizes vibration and noise, ensuring smooth operation in precision spindles and instruments.
- Preload & Temperature Stability: The bearing is supplied preloaded, enhancing system stiffness and rotational accuracy from the start. Its specified temperature range of -30°C to 110°C ensures reliable performance in varied operating environments.
71821 ACD/HCP4 Bearing Typical Application Areas
This high-performance angular contact ball bearing is ideally suited for:
- Machine Tool Spindles: High-speed milling, grinding, and turning centers.
- Precision Instruments: Measuring devices and laboratory equipment.
- High-Speed Motors and Drives: Where low friction and high rotational accuracy are critical.
- Aerospace & Defense Systems: Gyroscopes, radar systems, and other critical rotating assemblies.
