Official Answer
Answer
Load consistency in wave springs is highly sensitive to the installed work height $H_w$. Because the spring rate $k$ is linear in its design range, any variation in the housing or shaft axial dimensions directly affects the load $P = k(L_{free} - H_w)$. In a Crest-to-Crest assembly, cumulative tolerances of the waves and the alignment of peaks can introduce a 'shimming' effect. Engineers must specify a 'load at work height' rather than just a free height to ensure the assembly maintains the required preload, especially in bearing preloading where a deviation of $\pm 10\%$ in load can significantly alter bearing life.
