CuNi3Si – UNS.C70320 Nickel Silicon Bronze Alloys, which is an age-hardening alloy, higher alloyed in comparison with CuNi2Si, has higher contents of nickel and silicon in order to be able to adjust a particularly higher strength. It has an a-structure with very fine precipitations and recommends itself both for lead frames which require a high rigidity of the pins and for connector with high demands on the electrical conductivity, strength and relaxation behavior.