Official Answer
Answer
Wave springs interface with mating components at the wave crests. The surface finish of these mating surfaces (e.g., the bearing race or the housing shoulder) directly impacts the friction and wear. A surface roughness of $R_a 32 μin$ or better is recommended. A rough surface acts like a file, wearing down the wave crests and reducing the material thickness $t$. Since the spring rate $k$ is proportional to $t^3$, even a minor reduction in thickness leads to a significant loss in load. In high-frequency applications, this wear (fretting) can also generate metallic debris, which can contaminate sensitive components like optical sensors or precision bearings.
