High-performance alloys

Special requirements demand special materials. High-performance materials are achieved through the interaction of special alloy components and the process control tailored to them. These materials meet particularly highly demanding requirements for electrical conductivity, strength and forming capacity. These materials are also characterised by resilient properties that are not lost even at high temperatures. KEMPER’s high-performance materials can be identified by the KHP® (KEMPER High Performance) designation. KHP® materials are suitable for miniaturising plug connectors and electronic components and equally for contact elements in high-current applications.

CuSn bronzes – materials with individually adjustable properties

Bronze strips are known for their high degree of strength and good forming properties. They have good relaxation resistance at temperatures up to about 110°C and are therefore used for current-carrying spring elements in many cases.

For designers of electrical contacts, bronze offers even more advantages. For example, tempers can be adjusted almost infinitely to the requirements of further forming and the final function, irrespective of the standardised tempers or those shown on the data sheets. Moreover, it is possible to further improve the forming properties such as bendability by modifying the microstructure.

Copper materials

Copper materials for connectors and electromechanical applications

CuSn6 HP and CuSn8 HP

Our CuSn6 HP and CuSn8 HP materials are bronzes with particularly good bending properties. The very fine microstructure of these materials allows tighter radii than standard bronzes with the same strength and the same chemical composition. In other words, higher strengths are achievable with these materials with the same formability requirement.

The materials CuSn6 HP and CuSn8 HP are provided in strip thicknesses of up to 0.4 mm.


The purer the copper, the higher its electrical conductivity. This is why pure copper materials are particularly important in transferring current. In their undeformed state, our pure copper materials Cu-ETP and Cu-PHC reach a conductivity of at least 58 Ms/m and therefore 100% of the achievable conductivity specified for copper materials.

Cu-ETP can contain oxygen, while Cu-PHC is deoxidised by a slight addition of phosphor. Cu-PHC is therefore highly suitable for thermal joining processes, such as welding and soldering, in which residual oxygen are able to interfere. Moreover, Cu-PHC is fine-grained in its microstructure and is generally even more formable than Cu-ETP.

Stress relaxation

The operating life of a product is particularly important when using copper-based materials in connectors and contact springs. Resilient components are exposed to increasingly high temperatures, e.g. up to 150°C and above in automotive engineering. Resilience should be maintained over a long period of time so that current continues to be transferred even after continual use. Stress relaxation resistance is therefore a very important criterion in selecting a material.

In materials science, relaxation refers to a reduction of the resilience during constant elongation. The diagram shows how the contact force of a flexible spring decreases over time for the various alloys under the influence of temperature. This data helps simulate the endurance properties of electro-mechanical components and connectors.

Thermal relaxation

Thermal relaxation