71904 CD/HCP4A
Hybrid Ceramic Super Precision Bearings
Image may differ from product. See technical specification for details.
Part No.
Part No.
71904 CD/HCP4A
Basic Information
System of measurement
Metric
Weight
0.033 kg
Tolerance class
P4 (ABEC-7)
Seal type
Open
For load direction
Angular Contact
Main Dimensions
Bore diameter
20 mm
Bore diameter tolerance
-0.005mm to 0
Outside diameter
37 mm
Outside diameter tolerance
-0.006mm to 0
Width
9 mm
Width tolerance
-0.2mm to 0
Contact angle
15 °
Ball & Washer Dimensions
Ball diameter
4.762 mm
Ball quantity
15
Performance
Temperature range
-30° to 110 °C
Radial dynamic load rating
1361 lbf
Radial static load rating
720 lbf
Limiting speed
80 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:
$ 157.54
/ each
In Stock
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71904 CD/HCP4A Bearing Product Overview & Core Advantages
The 71904 CD/HCP4A is a single-row angular contact ball bearing engineered for ultra-high precision applications requiring exceptional rotational accuracy and rigidity. Manufactured to P4 (ABEC-7) tolerance class, it delivers superior running accuracy and dimensional stability. Its 15° contact angle is optimized for handling combined loads, with a primary capacity for high axial loads in one direction. The combination of a phenolic resin cage and ceramic balls enables outstanding high-speed performance up to 80,000 rpm, reduced friction, and extended service life, making it an ideal choice for demanding, high-velocity spindles.
71904 CD/HCP4A Bearing Model Code Explained, Specifications & Naming Convention
The model number 71904 CD/HCP4A provides detailed technical specifications:
- 71904: Basic bearing series and size designation (20mm bore, 37mm OD, 9mm width).
- C: Indicates a 15° contact angle.
- D: Signifies a high preload level for maximum rigidity.
- HC: Denotes the use of Hybrid Ceramic components (ceramic balls with steel rings).
- P4: Specifies the P4 (ABEC-7) tolerance class for ultra-precision.
- A: Indicates a 25° contact angle (Note: This appears to be a conflict with the 'C' designation in the provided data. Based on the provided 15° contact angle, the 'C' suffix is the correct identifier).
71904 CD/HCP4A Bearing Structural Features & Performance Benefits
- Hybrid Ceramic Construction: The combination of chrome steel rings and silicon nitride (Si3N4) ceramic balls significantly reduces centrifugal forces, lowers operating temperature, and provides electrical insulation. This results in higher limiting speeds, longer lubricant life, and superior performance in high-speed applications.
- Phenolic Resin Cage: The lightweight and robust phenolic cage contributes to smooth operation at ultra-high speeds, offering excellent strength and guidance with minimal friction.
- High Rigidity & Preload: The bearing is supplied with a high preload (D), which eliminates internal clearance. This ensures maximum system stiffness, precise shaft positioning, and dampens vibrations, which is critical for machining accuracy.
- Precision Engineering: Manufactured to P4 tolerance class with tight dimensional controls on bore, outside diameter, and width, guaranteeing consistent, high-precision performance.
71904 CD/HCP4A Bearing Typical Application Areas
This precision bearing is specifically designed for high-performance machinery, including:
- Machine Tool Spindles: High-speed milling, grinding, and turning centers.
- Precision Spindles: PCB drilling, engraving, and dental handpiece spindles.
- High-Frequency Motors: Spindles for routers and small precision motors.
- Aerospace & Instrumentation: Gyroscopes, navigation systems, and other critical instrumentation requiring minimal rotational error.
