71956 ACD/P4ATBTB
71900 Series Super Precision Angular Contact Ball Bearings
Image may differ from product. See technical specification for details.
Part No.
Part No.
71956 ACD/P4ATBTB
Basic Information
System of measurement
Metric
Weight
38.7 kg
Tolerance class
P4A
Seal type
Open
For load direction
Angular Contact
Main Dimensions
Bore diameter
280 mm
Bore diameter tolerance
-0.004mm to 0
Outside diameter
380 mm
Outside diameter tolerance
-0.004mm to 0
Width
138 mm
Width tolerance
-0.2mm to 0
Contact angle
25 °
Ball & Washer Dimensions
Ball diameter
30.162 mm
Ball quantity
31
Performance
Temperature range
- 30°C to 110 °C
Radial dynamic load rating
133200 lbf
Radial static load rating
290250 lbf
Limiting speed
7.5 X 1000 rpm
Lubrication
Lubricated
Matched arrangement
Triplex Back-to-Back (TBT)
Number of bearings in matched set
3
Universal matching bearing
No (Standard)
Preload
Light / Class B
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.
Our sales team will respond within 24 hours with a competitive quote tailored to your requirements.
REQUEST A QUOTE
- Fast delivery
- Enjoy discounts on bulk purchases
- Secure Payment
- Fast Global Shipping
71956 ACD/P4ATBTB Bearing Product Overview & Core Advantages
The 71956 ACD/P4ATBTB is a precision angular contact ball bearing designed for demanding applications requiring exceptional rigidity and accuracy. This triplex back-to-back (TBT) matched set delivers superior performance under combined loads, handling significant radial and axial forces simultaneously. Manufactured to P4A tolerance class with a light preload (Class B), it ensures smooth operation, minimal runout, and extended service life in high-precision machinery. Its open design, pre-lubricated for immediate use, offers versatility for systems with centralized lubrication.
Model Code Breakdown
| Code Segment | Technical Meaning |
|---|---|
| 71956 | Basic bearing series and size designation. |
| ACD | Angular Contact design with a 25° contact angle. |
| P4A | High precision tolerance class, exceeding ABEC 7/ISO P4 standards. |
| TBT | Triplex Back-to-Back arrangement of three bearings as a matched set. |
71956 ACD/P4ATBTB Bearing Structural Features & Performance Benefits
- High Rigidity & Load Capacity: The triplex back-to-back (TBT) configuration creates an extremely rigid bearing system, capable of withstanding high moment loads and substantial combined radial and axial loads (Dynamic Load Rating: 133,200 lbf, Static Load Rating: 290,250 lbf).
- Precision Performance: Manufactured to P4A tolerance class with a light preload, this set guarantees minimal vibration, high running accuracy, and precise shaft positioning, which is critical for high-speed spindles.
- Optimized Internal Design: Features 31 high-grade chrome steel balls and a phenolic cage, which contributes to lower friction, higher limiting speed (7,500 rpm), and stable operation under high centrifugal forces.
- Robust Construction: Made from through-hardened chrome steel for all rings and balls, ensuring high durability and resistance to wear in demanding operational environments.
71956 ACD/P4ATBTB Bearing Typical Application Areas
This bearing set is ideally suited for high-precision, high-rigidity applications, including:
- Machine Tool Spindles: High-speed milling, grinding, and turning centers.
- Precision Gearboxes: Industrial drives requiring accurate shaft alignment.
- High-Frequency Motors: Spindles for PCB drilling and other high-RPM applications.
- Industrial Pumps and Compressors: Where reliable performance under combined loads is essential.
