71904 ACD/P4ADBA
71900 Series Super Precision Angular Contact Ball Bearings
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Part No.
Part No.
71904 ACD/P4ADBA
Basic Information
System of measurement
Metric
Weight
0.07 kg
Tolerance class
P4A
Seal type
Open
For load direction
Angular Contact
Main Dimensions
Bore diameter
20 mm
Bore diameter tolerance
-0.004mm to 0
Outside diameter
37 mm
Outside diameter tolerance
-0.004mm to 0
Width
18 mm
Width tolerance
-0.2mm to 0
Contact angle
25 °
Ball & Washer Dimensions
Ball diameter
4.762 mm
Ball quantity
15
Performance
Temperature range
- 30°C to 110 °C
Radial dynamic load rating
2106 lbf
Radial static load rating
1372 lbf
Limiting speed
100.5 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
No drawings available at the moment, will be launched soon
In Stock
Price available upon request.
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71904 ACD/P4ADBA Bearing Product Overview & Core Advantages
The 71904 ACD/P4ADBA is a super-precision duplex angular contact ball bearing designed for the most demanding applications. It excels in scenarios requiring exceptional rotational accuracy, high rigidity, and reliable performance under combined loads. The back-to-back (DB) duplex arrangement provides excellent moment load capacity and axial rigidity, making it ideal for high-speed spindles and precision machinery. Manufactured to a P4A tolerance class, this bearing ensures minimal runout and consistent performance, supporting enhanced operational stability and longevity.
71904 ACD/P4ADBA Bearing Model Code Explained, Specifications & Naming Convention
The model number 71904 ACD/P4ADBA is decoded as follows:
- 71904: Denotes the bearing series and size. A 20mm bore, 37mm OD, and 18mm width.
- A: Indicates a 25° contact angle, optimized for carrying significant axial loads.
- C: Specifies an Extra Light (Class A) preload, which minimizes deflection and ensures smooth, precise operation at high speeds.
- D: Signifies the bearing is part of a Duplex Back-to-Back (DB) matched set.
- P4A: The tolerance class, indicating super-precision levels with strict limits on dimensional and running accuracy.
- DB: Confirms the Duplex Back-to-Back mounting arrangement.
- A: Reiterates the 25° contact angle for the matched set.
71904 ACD/P4ADBA Bearing Structural Features & Performance Benefits
- High Rigidity & Stability: The duplex back-to-back (DB) design creates a wide, rigid support system that effectively resists moment loads and shaft deflection, ensuring precise alignment and positioning.
- Superior Load Capacity: With a 25° contact angle and a dynamic load rating of 2106 lbf, this bearing is engineered to handle significant combined radial and axial loads simultaneously.
- High-Speed Performance: The lightweight phenolic resin cage and optimized internal geometry contribute to lower friction and inertia, enabling a high limiting speed of 100,500 rpm.
- Precision Engineering: Manufactured to P4A tolerance standards with a bore and OD tolerance of -0.004mm to 0, this bearing guarantees exceptional running accuracy and minimal vibration for ultra-precise applications.
- Material Quality: Constructed from high-grade chrome steel for rings and balls, ensuring high durability, wear resistance, and consistent performance within a temperature range of -30°C to 110°C.
71904 ACD/P4ADBA Bearing Typical Application Areas
This high-precision bearing is specifically designed for advanced machinery where accuracy and speed are paramount. Key applications include:
- Machine Tool Spindles: High-speed milling, grinding, and turning centers.
- Precision Rotary Tables and indexing heads.
- High-Frequency Spindles for PCB drilling and routing.
- Medical Equipment such as high-speed dental handpieces and laboratory centrifuges.
- Advanced Robotics and automation systems requiring precise joint movement.
