Official Answer
Answer
The stress during installation is much higher than the stress in the operating position. For an external ring, the fiber stress $ ext{σ}$ when expanded over a shaft is $ ext{σ} = _x000c_rac{E imes t imes (D_s - D_g)}{D_m^2}$, where $D_s$ is the shaft diameter and $D_g$ is the ring's free diameter. To prevent 'Permanent Set' (plastic deformation), the calculated stress $ ext{σ}$ must be less than the material's yield strength $S_y$. If the calculation shows $ ext{σ} > S_y$, the designer must either: 1) Increase the ring's free diameter (reducing the 'cling'), 2) Use a material with higher yield strength, or 3) Reduce the ring thickness $t$.
