The copper plating of the pins is historically a typical and recognizable feature of various ZMC chains.
The galvanic copper coating is performed on the pins of our chains for precise technical reasons that involve both the quality of the product and safety at work.
The riveting operation concludes the assembly of the chains, it provides a plastic deformation of the head of the pins to ensure the mechanical resistance in the presence of axial thrusts.
To obtain an effective riveting it is necessary that the pins are not excessively hard, the same characteristic is important to prevent metal splinters from detaching and being projected in the surrounding area while the component is undergoing deformation.
The resistance to wear of the chain, however, would require exactly the opposite, that is a pin with the highest possible surface hardness.
The copper plating intervenes precisely to find a solution to these two opposite requirements. The pins are completely coated with copper, afterwards they are ground on the cylindrical and the coating remains only on the heads. During the heat treatment process, copper inhibits the spread of carbon in the metal matrix of the steel, so that the areas covered with copper do not harden. At the end of the process the copper-plated pins of ZMC have both the ideal characteristics: high hardness of the cylindrical part, such as to guarantee the best performance of resistance to wear, and a soft head, easy and safe to rivet.
A further advantage guaranteed by copper plating is the protection against oxidation that the galvanic coating guarantees to the pin head, including the area of press fit with the plate.
For more information, don’t hesitate to contact us