Coordinate Measuring Machines (CMMs) are widely used in industry to inspect any kind of workpiece form and assess conformity to tolerance specifications. However, for each tolerance, there exist specific instruments, that provide more accurate results, but are not always available in industrial practice. This paper deals with an experimental study of the influence of different factors (such as sample size, sampling strategy, and form evaluation method) on CMM and roundness tester, measuring processes capability in the control of roundness tolerance