Copper is much softer than steel, and its elasticity and ability to resist decay are not strong. After adding some beryllium to copper, its hardness is enhanced, its elasticity is excellent, its resistance to losses is high, and it also has high conductivity. Springs made of beryllium bronze can be tightened hundreds of millions of times or more.

If the volume change of the part is uniform and its density advances uniformly, it has no effect on the overall shape of the part. This uniform change can be considered in the planning of size design without significant results. On the other hand, assuming that the volume change is uneven, deformation results will occur. There are several factors that can cause uneven age hardening of beryllium copper parts. Uneven temperature is a root cause of deformation when dealing with large-sized or elongated parts. However, small parts formed by stamping or machining, even when the aging temperature is uniform, can also result in changes in the outcome.