Official Answer
Answer
Nested wave springs consist of multiple turns coiled in parallel (stacked) rather than in series (crest-to-crest). The total load $P_{total}$ for a nested spring is $P_{total} = P_{single} \cdot N$, where $N$ is the number of nested turns. This design is utilized when extremely high forces are required within a very small axial space. Because the turns are in parallel, the spring rate $k$ increases proportionally with the number of turns: $k_{total} = N \cdot \frac{E b t^3 n^4}{D_m^3}$. This is the inverse of a multi-turn crest-to-crest spring, where the rate decreases as $1/N$. Nested springs are ideal for high-pressure seals and heavy-duty valve preloading where space constraints preclude the use of heavy-gauge wire coil springs.
