In this work the multi-factor, non-linear dependencies between main (tangential) FC and normal (radial) FN cutting forces upon two machining parameters by up-routing and down-routing wood of Douglas fir (Pseudotsuga menziesii) and Oak (Quercus petraea) were evaluated. The relationships are graphically illustrated and discussed.  The obtained data were compared with cutting forces evolution models according to grain orientation from the literature in order to verify if literature statements or models comply with measured data. Evidence of several contradictions was found relative to results from available literature.