71908 CD/P4ADBAGMM1
71900 Series Super Precision Angular Contact Ball Bearings
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Part No.
Part No.
71908 CD/P4ADBAGMM1
Basic Information
System of measurement
Metric
Weight
0.22 kg
Tolerance class
P4A
Seal type
Open
For load direction
Angular Contact
Main Dimensions
Bore diameter
40 mm
Bore diameter tolerance
-0.004mm to 0
Outside diameter
62 mm
Outside diameter tolerance
-0.004mm to 0
Width
24 mm
Width tolerance
-0.2mm to 0
Contact angle
15 °
Ball & Washer Dimensions
Ball diameter
6.35 mm
Ball quantity
21
Performance
Temperature range
- 30°C to 110 °C
Radial dynamic load rating
4478 lbf
Radial static load rating
3825 lbf
Limiting speed
56 X 1000 rpm
Lubrication
Grease
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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71908 CD/P4ADBAGMM1 Bearing Product Overview & Core Advantages
The 71908 CD/P4ADBAGMM1 is a super-precision angular contact ball bearing designed for applications demanding exceptional rotational accuracy and rigidity. This duplex back-to-back (DB) matched pair is preloaded to Extra Light (Class A) specifications, ensuring minimal axial and radial runout for superior performance. Its primary advantage lies in its ability to handle combined loads (radial and axial) simultaneously with high stability, making it an ideal choice for high-speed spindles and other precision machinery requiring high rigidity and excellent running accuracy.
71908 CD/P4ADBAGMM1 Bearing Model Code Explained, Specifications & Naming Convention
| Code Segment | Technical Meaning |
|---|---|
| 71908 | Basic bearing series, indicating a super-precision, light series angular contact ball bearing. |
| C | 15° contact angle, optimized for high-speed applications and moderate axial loads. |
| D | Duplex bearing (two single bearings supplied as a set). |
| P4A | High precision tolerance class (equivalent to ABEC 7), ensuring extremely tight dimensional and running accuracy. |
| DB | Back-to-Back mounting arrangement. This configuration provides high moment rigidity and is effective in withstanding overturning moments. |
| A | Specifies the preload level: Extra Light (Class A), which minimizes friction and heat generation at high speeds. |
| GMM | Indicates the bearing is supplied as a universally matched pair for back-to-back (DB) mounting, ensuring optimal performance and load distribution. |
| 1 | Internal code related to specific manufacturing or grouping standards. |
71908 CD/P4ADBAGMM1 Bearing Structural Features & Performance Benefits
- High Rigidity and Stability: The duplex back-to-back (DB) arrangement creates a wide, stable support system that significantly increases moment rigidity, making it resistant to deflection under combined loads.
- Super-Precision Performance: Manufactured to P4A tolerance class, this bearing guarantees extremely low runout and vibration, which is critical for achieving high surface finish and positioning accuracy in machine tools.
- Optimized High-Speed Capability: The 15° contact angle and lightweight phenolic resin cage reduce centrifugal forces and friction, enabling stable operation at the high limiting speed of 56,000 rpm.
- Superior Material Integrity: Constructed from high-grade chrome steel for both rings and balls, ensuring long-term dimensional stability and durability under demanding operating conditions.
71908 CD/P4ADBAGMM1 Bearing Typical Application Areas
The 71908 CD/P4ADBAGMM1 is engineered for the most demanding precision applications, including:
- High-Speed Machine Tool Spindles (e.g., for milling, grinding, and drilling)
- Precision Grinding Spindles
- High-Frequency Motors
- Industrial Pumps and Compressors requiring high shaft stability
- Aerospace and Defense Instrumentation
- Medical and Dental Equipment spindles
