S7208 ACD/HCP4A
Hybrid Ceramic Super Precision Bearings
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Part No.
Part No.
S7208 ACD/HCP4A
Basic Information
System of measurement
Metric
Weight
0.33 kg
Tolerance class
P4 (ABEC-7)
Seal type
Sealed
For load direction
Angular Contact
Main Dimensions
Bore diameter
40 mm
Bore diameter tolerance
-0.006mm to 0
Outside diameter
80 mm
Outside diameter tolerance
-0.007mm to 0
Width
18 mm
Width tolerance
-0.2mm to 0
Contact angle
25 °
Ball & Washer Dimensions
Ball diameter
11.112 mm
Ball quantity
14
Performance
Temperature range
-30° to 110 °C
Radial dynamic load rating
7178 lbf
Radial static load rating
5130 lbf
Limiting speed
19 X 1000 rpm
Lubrication
Lubricated
Matched arrangement
Single
Preload
Available
Materials
Ring material
Chrome Steel
Ball material
Ceramic
Cage material
Phenolic
Technical Drawings
No drawings available at the moment, will be launched soon
Price:
$ 311.49
/ each
In Stock
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S7208 ACD/HCP4A Bearing Product Overview & Core Advantages
The S7208 ACD/HCP4A is a high-precision, single-row angular contact ball bearing engineered for applications demanding exceptional speed, rigidity, and accuracy. Its defining characteristic is the 25° contact angle and P4 (ABEC-7) precision class, enabling it to handle significant combined loads (radial and axial) simultaneously. The use of ceramic balls and a phenolic cage contributes to lower friction, higher limiting speeds, and reduced weight, making it an ideal solution for high-performance, high-reliability spindles and machinery.
S7208 ACD/HCP4A Bearing Model Code Explained, Specifications & Naming Convention
| Code Segment | Technical Meaning |
|---|---|
| S7208 ACD | Indicates a single-row angular contact ball bearing with a 40mm bore, 80mm OD, and 18mm width. The "A" signifies a 25° contact angle for optimal axial load capacity. "CD" denotes a specific internal design and clearance for preload. |
| HC | Refers to the Hybrid Ceramic construction, featuring ceramic balls and steel rings. This reduces centrifugal forces, lowers operating temperature, and extends service life at high speeds. |
| P4 | Specifies the tolerance class P4 (ABEC-7), indicating extremely tight dimensional and running accuracy for applications requiring superior rotational precision and minimal runout. |
| Sealed / Lubricated | The bearing is sealed to protect against contamination and is pre-lubricated, offering a maintenance-free solution within its specified temperature range. |
S7208 ACD/HCP4A Bearing Structural Features & Performance Benefits
- Hybrid Ceramic Design: The combination of chrome steel rings and silicon nitride (Si3N4) ceramic balls provides superior performance. Ceramic balls are lighter, harder, and have a lower coefficient of thermal expansion than steel, leading to higher limiting speeds (19,000 rpm), reduced heat generation, and longer service life.
- High Rigidity & Load Capacity: The 25° contact angle is optimized to support substantial combined radial and axial loads (Dynamic: 7178 lbf, Static: 5130 lbf), ensuring stable operation under demanding conditions.
- Precision & Stability: Manufactured to P4 precision class tolerances, this bearing guarantees minimal vibration and high running accuracy, which is critical for maintaining machining quality and surface finish.
- Phenolic Cage: The lightweight and robust phenolic resin cage ensures excellent guidance of the ceramic balls at high speeds, contributing to smooth operation and high acceleration capability.
S7208 ACD/HCP4A Bearing Typical Application Areas
This high-speed precision angular contact bearing is specifically designed for advanced applications, including:
- Machine Tool Spindles: High-speed milling, grinding, and turning centers.
- Precision Robotics: High-accuracy robotic arms and joints.
- Aerospace & Defense Systems: Gyroscopes, radar systems, and auxiliary power units.
- High-Frequency Motors & Spindles: Where extreme rotational accuracy and speed are paramount.
