Technical Analysis: Why the Loaded Value is Used as the Standard Test Basis for the Measurement of Disc Spring Force

In the quality control and performance verification of disc springs, force measurement is a critical step. A fundamental question arises: Does the standard specify that the measured force value refers to measurements taken during loading or unloading? Jiangsu Sunzo Spring, combining national standards with engineering practice, clarifies this testing benchmark for disc springs.

1、A clear benchmark for standard testing: loading process

As stipulated in GB/T 1972 (National Standard for Disc Spring) and industry guidelines, the standard test value for disc spring force refers specifically to measurements taken during loading, not unloading. This regulation is grounded in multiple engineering considerations:

1. Design validation compatibility

The force predicted by the design theory of disc spring (e.g. AL formula) is the force needed to reach the specified deformation, i.e. the loading force.

2. Correspondence of application conditions

In practical applications, the primary function of most disc springs is to bear loads and provide counterforce. For instance, they may serve as fastening elements to deliver clamping force or act as shock absorbers to absorb impact energy. These operational scenarios correspond to the compression (loading) process of disc springs. Therefore, the loading force value is the parameter most directly related to actual performance.

3. Consistency and Reproducibility of the Test

The loading process is relatively easier to control and standardize. During testing, by controlling the displacement or speed of the press head, the force values on the loading curve can be obtained stably. This facilitates the comparison and benchmarking of test results between different laboratories and batches of products.

2、The difference between loading and unloading values: the lag effect

It should be noted that due to internal material friction and interdisc friction during assembly, the loading and unloading curves of disc springs do not coincide, forming a hysteresis loop. Typically, under the same deformation, the unloading force is slightly lower than the loading force. Using unloading force as the standard would fail to accurately reflect the actual performance of disc springs under initial load conditions.

3、The Test Practice of Three Groups of Elasticity: Rigorous Implementation of Standards

At Jiangsu Sunzo Spring's modern testing center, we rigorously conduct force value tests in strict compliance with national standards and client specifications.

Test method: The force value during loading process was used as the criterion.

Equipment and Precision: Highprecision testing machines are employed to ensure stable and controllable loading rates, with accurate and reliable data acquisition.

Data report: Test reports clearly specify test conditions (e.g., loading to H₀ 0.75h₀), ensuring data transparency and comparability.

We firmly believe that rigorous and unified testing standards are the cornerstone of quality reliability. Through precise control and testing of loading force values, we ensure every disc spring delivered meets design expectations and standard requirements, providing your equipment with precise elastic performance assurance.