Official Answer
Answer
Wave springs are highly sensitive to the installed height ($H_i$). Because the spring rate $K$ is often high, a small variation in $H_i$ leads to a large variation in load $P$ ($P = K \times (H_{free} - H_i)$). Tolerance stack-up from the housing depth, the thickness of mating parts, and the spring's own free height can result in a load variance of $\pm 10\%$ to $\pm 20\%$. To achieve higher precision, engineers may use 'load-sorted' springs or include a shim to adjust the working cavity. Additionally, the use of 'parallel-coiled' nested springs can provide more consistent loads because the load is distributed over multiple layers, effectively averaging out minor geometric variations in individual waves.
