Why Does The Contact Resistance Increase When Using A Cold-pressed Pin?

When metals are physically bonded together, the microscopic contact state determines the smoothness of current flow. If you observe abnormal temperature rise in the system, it usually indicates that increased contact resistance in the male crimp contact crimping has become a latent problem.

Core Factors Affecting Resistance Fluctuations

To address this technical challenge, the microscopic changes at the contact interface can be observed from the following dimensions:

• Stress relaxation phenomenon: Metals undergo creep under long-term compression. Even with a large initial crimping force, the internal stress of the metal slowly releases over time, leading to a decrease in physical pressure at the contact surface.

• Surface oxide layer interference: Even on surfaces that appear extremely smooth to the naked eye, a very thin insulating oxide film can form due to oxygen entering tiny gaps in the air.

• Cross-section compression ratio deviation: Excessive compression can damage the conductor core, reducing the conductive area; insufficient compression prevents the expulsion of air from the gaps.

Environmental stress challenges to cold-pressed pin performance

Fluctuations in the external environment often contribute to performance degradation. Under conditions of frequent vibration or significant temperature differences, the difference in thermal expansion coefficients between the crimp contact and the conductor materials can cause micron-level displacement at the interface. This fretting wear continuously peels away the surface plating, exposing the more easily oxidized underlying metal, resulting in a step-like jump in resistance.

For connection points exposed to high humidity environments for extended periods, electrochemical corrosion is also a significant variable. When moisture seeps into the crimping cavity, the resulting electrolyte environment accelerates the loss of metal ions.

Practical Approaches to Improving Connection Stability

The key to controlling resistance lies in the strict control of process parameters. Using professional crimping dies can maintain constant deformation, allowing the core wires inside the crimp contact pin to achieve a molecular bonding state similar to "cold welding." Regular pull-out force testing and cross-sectional metallographic analysis provide a more direct observation of the density inside the crimping cavity.

If you require a more in-depth customized crimping process solution for specific operating conditions, or wish to obtain a more detailed comparison table of cold crimping pin technical parameters, please feel free to contact us privately.