Static Balance and Dynamic Balance are similar, but not the same. Static balance is often given as oz inches, dynamic balance as velocity in Inches Per Second. The only reliable way to convert inch oz to a dynamic measure is to measure the affect of a given weight (maximum permissible imbalance tolerance in oz in) in the dynamic condition via vector analysis. One must be careful because there are tons of caveats on the use of this method - rigid body or "live", target speed, potential for critical speeds causing non linearity and so on. It is possible to be dynamically balanced but not be in static balance limits. Since a part lives in the dynamic environment, this then becomes the driver for maintainers. I have never seen a dynamic component wear out in a static on the shelf environment - ADs notwithstanding.