Official Answer
Answer
Wave springs require parallel mating surfaces to ensure even load distribution across all wave crests. If the surfaces are tilted by an angle $ heta$, the load $P$ becomes eccentric, causing some waves to compress more than others. This leads to localized overstressing, where $S_{local} = S_{calc} imes (1 + _x000c_rac{e}{k})$ where $e$ is eccentricity. The result is premature fatigue failure and a 'cocked' assembly that may cause uneven wear on seals or bearings. In precision optics or high-speed rotating equipment, mating surfaces should be ground to a parallelism within $0.001$ inch per inch of diameter.
