In the manufacturing industry, the internal turning or boring operation is a common metal working process that is usually associated with vibration problems. Vibration in boring operations is usually inevitable. This necessitates extra care being taken in production planning and preparation. Thus, the vibration problems in internal turning considerably influence important factors such as productivity, production costs, etc. In order to gain further understanding of the dynamic behaviour of clamped boring bars in the metalcutting process experimental methods may be utilized. Two experimental methods have been used in order to investigate dynamic properties of a clamped boring bar: an experimental modal analysis and an operating deflection shape analysis. The results indicate a correlation between the shapes of the deflection shapes and/or mode shapes produced by the two different analysis methods. On the other hand, the orientation of the forced deflection shapes and/or mode shapes and the resonance frequencies demonstrates differences between the two methods. During continuous cutting, it is demonstrated that the bending motion of the first two resonance frequencies is to a large extent in the cutting speed direction.