In metal cutting the vibration problem of boring bars remains to be one of the most problematic and productivity degrading. A boring bar is very flexible and easily subjected to vibrations due to its large length to diameter ratio, which generally is required to perform internal turning. The boring bar vibrations appear at its first eigenfrequncies, which correspond to the boring bar’s first bending modes that are affected by boring bar’s boundary conditions applied by the clamping and workpiece in the lathe. Therefore the investigation of spatial dynamic properties of boring bars is of great importance for the understanding of the mechanism and nature of boring bars vibrations. This paper addresses the problem of building an accurate 3-D finite element model of a boring bar with ”free-free” boundary conditions. The questions of appropriate meshing and its influence on the boring bar’s spatial dynamic properties estimates as well as modeling the affect of mass loading are discussed. The results from simulations of 3-D finite element model of the boring bar, i.e. its first eigenmodes and eigenfrequencies, are correlated with the results obtained both from experimental modal analysis and analytical calculations using an Euler-Bernoulli model.