the highest strength of any copper alloy, which is achieved by heat treatment (ageing) and cold working
copper beryllium; copper alloys C17000 - C17530 incl
see also high-performance alloys
note: Wrought alloys are used in applications such as electronic connector contacts, electrical equipment such as switch and relay blades, control bearings, housings for magnetic sensing devices, non sparking applications, small springs, high speed plastic molds and resistance welding systems. Cast beryllium coppers are frequently used for plastic injection molds.
standard ASTM B846