Answer
Wave springs must be centered to prevent uneven loading and wear. For static applications, centering on the outside diameter (OD) via a housing bore is typically sufficient. However, for dynamic applications involving high-speed reciprocation, internal centering on a shaft (ID) is preferred to minimize the mass-moment of inertia and prevent the spring from 'walking' or buckling. The clearance between the spring and the centering pilot should be $0.010$-$0.020$ inches to allow for the radial expansion discussed in previous design calculations. For multi-turn springs, a shim or spacer should be used if the spring is seating against a rotating component to prevent the wave peaks from 'digging in' and creating a torsional drag that could cause the spring to uncoil or fail prematurely.
