The mysterious world of radial clearance, axial clearance and contact angle
Do you know what is radial clearance, axial clearance, and contact angle? These concepts are relatively unfamiliar to ordinary people, but they are actually quite important in the engineering world.
Simply put, radial clearance is the radial distance between the inner and outer rings of a bearing. Axial clearance is the axial distance between the inner and outer rings of a bearing. The contact angle is the angle between the radial plane and the axial plane.
But what exactly do these concepts mean, and why are they important? Read on to find out!

What is radial clearance?
Radial clearance is the distance between the outer and inner rings of a bearing. This clearance is necessary to accommodate possible misalignment between the two rings during operation. The amount of radial clearance required for a bearing depends on the type of application and the amount of misalignment expected.
In general, bearings with greater radial clearance can tolerate greater misalignment than bearings with less radial clearance. However, bearings with excessive radial clearance will generate noise and possibly reduce accuracy. Therefore, it is important to select a bearing with the proper amount of radial clearance for the application.
What is axial clearance?
Axial play is the small amount of space between the axis of a rotating shaft and the housing or bearing that supports it. This clearance is necessary to allow for thermal expansion of the shaft, as well as other factors such as manufacturing tolerances. Too much axial play can cause excessive vibration and wear, while too little play can cause the shaft to seize and possibly fail. Shock journal bearings and ball bearings are usually designed with a specific amount of end play in mind.
Contact angle: the key to efficient bearings?
The contact angle is the angle between a bearing surface and the shaft it is mounted on. It is a crucial factor in determining the efficiency of a bearing, as it affects the amount of friction between the two surfaces.
Bearing surfaces with a small contact angle are more efficient than those with a large contact angle. This is because a smaller contact angle results in less friction between the bearing and the shaft, which means the bearing can spin more freely.
While it is important to have an efficient bearing, it is also important to make sure that the contact angle is not too small. If the contact angle is too small, then the bearing will not be able to stay mounted on the shaft and will eventually fall off.
The optimum contact angle for a bearing depends on a number of factors, such as the type of material the bearing is made from.
How do these concepts come together to create the perfect bearing?
In order for a bearing to work perfectly, all its parts must also fit together perfectly. The most important part of a bearing is the ball, which must be perfectly spherical. The track the ball sits on must also be very smooth, and the cage that holds everything together must be made of the right material.
All these parts must be assembled with high precision. Even tiny defects can cause bearing failure. But when everything is just right, you have a perfect bearing that will work flawlessly for years to come.
General: radial play, axial play, and contact angle
Radial and axial play are the two main types of play a shaft can have. Radial clearance is the gap between the shaft and the housing bore, while axial clearance is the gap between the shaft and the housing face. Both clearance types can be measured in inches or millimeters. The contact angle is another important factor to consider when installing the shaft in the housing. This angle describes the angle of the shaft surface relative to the housing bore. When installing a shaft in a housing, there are three factors to consider – radial play, axial play, and contact angle.
Radial clearance, axial clearance, and contact angle all play an important role in the performance of the shaft in the housing. By understanding these clearance types and how they affect each other, you can ensure that your shaft will perform properly.
How do radial and axial clearances affect the contact angle?
Both radial and axial clearances affect the contact angle. Radial clearance is the distance between the center of the contact zone and the edge of the journal. Axial clearance is the distance between the journal and the bearing. Generally speaking, the influence of radial clearance on contact angle is greater than that of axial clearance.
Radial clearance affects the contact angle because it determines the amount of space between the journal and the bearing. This space allows lubricant to flow into the contact area, reducing friction and wear. On the other hand, axial play affects the contact angle because it determines the amount of space between the journal and the bearing. This space allows lubricant to flow into the contact area, reducing friction and wear.
Why are radial and axial play important?
Radial and axial clearance are important criteria when evaluating bearings. Radial clearance is the percentage of the total bearing width that exists between the bearing’s inner and outer rings, while axial clearance is the percentage of the total bearing width that exists between the bearing’s inner and outer rings along the axis of rotation.
Clearance is important because it allows the bearing to function properly. If the clearance is too small, the bearing will not rotate smoothly. Conversely, if the clearance is too large, the bearing will have excessive play and may generate noise.
Strive to maintain proper radial and axial clearance in our bearings to ensure proper operation and long life.
Conclusion
Radial clearance, axial clearance, and contact angle all affect the overall performance of a bearing. Each plays a vital role in keeping the bearing running smoothly and efficiently. Without proper clearance, bearings can suffer from a number of problems including poor lubrication, excessive wear, and premature failure. If you have more questions about bearings, please contact us at sales@yuanhecd.com!