Abstract
The mechanism of the cutting process in drilling by a twist drill has not well understood yet because a drill with a complex geometry of two cutting lips is used and it causes the dynamical interaction with some parts of a machine. In this paper some experiments were performed to investigate the influence of difference of rigidity of main spindle and difference of drill point styles to cutting process. As the result, there was not interaction between two lips under the usage of high rigid spindle but was in low rigid spindle. Drill walking and rifling phenomena occurred in case of low rigid spindle. It is found that comparing other points the spiral drill point has the ability of reduction of interaction between lips.
