71821 ACD/HCP4DBA
Hybrid Ceramic Super Precision Bearings
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71821 ACD/HCP4DBA Bearing Product Overview & Core Advantages
The 71821 ACD/HCP4DBA is a precision angular contact ball bearing designed for applications demanding exceptional accuracy and high-speed performance. This duplex back-to-back (DB) matched set features an Extra Light (Class A) preload, providing superior system rigidity and rotational accuracy. Its construction with ceramic balls and a phenolic cage enables outstanding high-speed capabilities and reduced rotational mass. Engineered to handle combined loads, this bearing is ideal for high-reliability, precision machinery where minimal runout and thermal stability are critical.
71821 ACD/HCP4DBA Bearing Model Code Explained, Specifications & Naming Convention
| Code Segment | Technical Meaning |
|---|---|
| 71821 | Basic bearing designation |
| ACD | Angular Contact Design, 25° contact angle |
| HC | Hybrid Ceramic (Ceramic balls with steel rings) |
| P4 | Precision tolerance class (superior running accuracy) |
| DB | Duplex Back-to-Back arrangement |
| A | Extra Light preload classification |
71821 ACD/HCP4DBA Bearing Structural Features & Performance Benefits
High Rigidity & System Stability: The duplex back-to-back (DB) arrangement creates a rigid bearing system that effectively resists moment loads and maintains precise shaft positioning under combined radial and axial loads.
Superior High-Speed Performance: The combination of ceramic balls (lower density, reduced centrifugal forces) and a lightweight phenolic cage enables exceptional limiting speeds of 16,000 rpm, making it an ideal high-speed bearing solution.
Enhanced Precision & Accuracy: Manufactured to P4 tolerance class with an Extra Light preload, this bearing ensures minimal runout, excellent rotational accuracy, and consistent performance in precision applications.
Optimized Load Capacity: With a 25° contact angle and 35 ceramic balls, the bearing provides balanced radial and axial load ratings (7,898 lbf dynamic / 12,825 lbf static) for demanding operational conditions.
71821 ACD/HCP4DBA Bearing Typical Application Areas
This precision angular contact ball bearing is specifically engineered for high-performance applications including:
- Machine Tool Spindles - High-speed machining centers and precision grinding spindles
- High-Speed Motors & Spindles - CNC routers, PCB drilling machines, and dental handpieces
- Precision Instrumentation - Measuring equipment, optical scanners, and laboratory apparatus
- Aerospace Components - Gyroscopes, navigation systems, and auxiliary power units
- Robotics & Automation - High-precision robotic arms and rotary tables
