When a machine needs to be vibration isolated because it produces significant unbalanced forces that would cause excessive motion if supported directly on spring or rubber-based isolators, an inertia base should be utilized instead. In cases when the machine is unstable by nature or is sensitive to outside pressures, they should also be used.

There are numerous common sizes for inertia. Normally, we would advise 6 isolators or more for particularly large bases for frames longer than 2400 mm. The base must be filled with concrete that weighs between 2300 and 2700 kilograms per cubic meter.