Beryllium is a metal that is lighter than aluminum and stronger than steel, in addition to being a very good conductor of heat and electricity.
Although Beryllium copper is a widely used material with good spring properties, the presence of the metal Beryllium in the alloy can be a problem. If leaf springs are to be manufactured from Beryllium copper, laser cutting is an undesirable technique because the Beryllium vapor that can be released during this process is extremely toxic.
Phosphor bronze is an alloy of copper with tin and phosphorus. The material is satisfactory in almost all situations for contact and conduction springs. It is tough, strong and has a low coefficient of friction. A good alternative to Beryllium copper!
Brass is very similar to phosphor bronze, but does not have as good mechanical properties.