In practical applications, disc springs are often stacked to achieve the required load and deflection. However, during testing, the measured force at the same compression height may differ between loading and unloading.

This difference is mainly caused by friction.

1. Where Does Friction Occur?

Friction in disc spring stacks generally comes from three areas:

• Between disc springs: Contact surfaces create friction as the springs slide against each other.

• At support surfaces: Friction occurs between the springs and their supporting surfaces.

• At guide components: Contact with guide rods or sleeves may create additional resistance.

2. Why Are Loading and Unloading Forces Different?

During loading, external pressure compresses the springs, while part of the applied energy is used to overcome friction.

During unloading, the springs recover through their elasticity, but friction continues to resist their movement.

As a result, the loading and unloading curves do not completely overlap. This phenomenon is known as hysteresis.

3. How Can Friction Be Reduced?

To minimize friction-related effects, consider the following:

• Select an appropriate stacking arrangement.

• Ensure good surface quality on contact and support areas.

• Optimize the guiding structure.

• Apply suitable lubrication when required.

• Test both loading and unloading performance under actual working conditions.

The performance of a disc spring stack depends not only on material, dimensions, and design, but also on friction between contact surfaces.

At Raleigh Spring, we manufacture disc springs and other spring components, offering customized solutions based on customers' load requirements, dimensions, and operating conditions.