The geometrical complexity of a drill and the intricate relationships betwe
en the parameters affecting the drilling process and the product quality, c
oncern both the drill manufacturers and its users. The modelling of the pro
cess and parameters is extremely difficult. This work presents a view on th
e potential dependence of the hole quality on drill wandering. The bending
stiffness of the drill is discussed together with its skewness. Experimenta
l results are included and location errors are presented.