71821 CD/P4DBA
71800 Series Super Precision Angular Contact Ball Bearings
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Part No.
Part No.
71821 CD/P4DBA
Basic Information
System of measurement
Metric
Weight
0.64 kg
Tolerance class
P4
Seal type
Open
For load direction
Angular Contact
Main Dimensions
Bore diameter
105 mm
Bore diameter tolerance
-0.004mm to 0
Outside diameter
130 mm
Outside diameter tolerance
-0.004mm to 0
Width
26 mm
Width tolerance
-0.2mm to 0
Contact angle
15 °
Ball & Washer Dimensions
Ball diameter
7.144 mm
Ball quantity
35
Performance
Temperature range
- 30°C to 110 °C
Radial dynamic load rating
8348 lbf
Radial static load rating
13500 lbf
Limiting speed
16 X 1000 rpm
Lubrication
Lubricated
Matched arrangement
Duplex Back-to-Back (DB)
Number of bearings in matched set
2
Universal matching bearing
No (Standard)
Preload
Extra light / Class A
Materials
Ring material
Chrome Steel
Ball material
Chrome Steel
Cage material
Phenolic
Technical Drawings
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In Stock
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71821 CD/P4DBA Bearing Product Overview & Core Advantages
The 71821 CD/P4DBA is a precision duplex angular contact ball bearing designed for applications demanding exceptional rotational accuracy and rigidity. This back-to-back (DB) matched set is preloaded to Extra Light (Class A) specifications, ensuring high system stiffness and minimal runout under complex loading conditions. Its primary advantage lies in its ability to support combined radial and axial loads simultaneously, making it an ideal choice for high-precision spindles and other critical machinery where reliability and performance are paramount.
71821 CD/P4DBA Bearing Model Code Explained, Specifications & Naming Convention
| Code Segment | Technical Meaning |
|---|---|
| 71821 | Basic bearing designation indicating size and type. |
| C | 15° contact angle. |
| D | Duplex bearing (two single bearings paired). |
| DB | Back-to-Back mounting arrangement for high moment rigidity. |
| P4 | High Precision tolerance class (superior to ABEC 7). |
| A | Extra Light Preload for minimal friction and high-speed operation. |
71821 CD/P4DBA Bearing Structural Features & Performance Benefits
- High Rigidity & Stability: The back-to-back (DB) duplex arrangement creates a wide effective spread, significantly increasing the bearing set's resistance to moment loads and ensuring exceptional operational stability.
- Optimized Load Capacity: With a 15° contact angle and a dynamic load rating of 8348 lbf, this bearing is engineered to handle significant combined loads (radial and axial) efficiently.
- Precision & Speed: Manufactured to a P4 tolerance class and featuring a lightweight phenolic cage, this bearing achieves a high limiting speed of 16,000 rpm with minimal vibration and heat generation.
- Material Integrity: Constructed from chrome steel for both rings and balls, this bearing offers high hardness, wear resistance, and long service life under demanding conditions.
71821 CD/P4DBA Bearing Typical Application Areas
This precision duplex bearing is ideally suited for high-performance applications, including:
- Machine Tool Spindles (milling, grinding, turning)
- High-Frequency Spindles
- Precision Gearboxes
- Medical and Laboratory Equipment
- Robotic Arm Joints and Drives
