AgCu rivet:

This contact has good electrical conductivity and its surface is not liable to oxidization. The addition of 3 - 30% copper may remarkably improve the silver's flame resistance. Hence, copper contact material may be used in current strength up to 16A. The addition of copper, especially of high copper content, for example 10%, will greatly reduce material transferring during DC working conditions. It is widely used in AC contactors, relays, electric tool switches, buttons, timers, and other household electrical appliances.