A gundrilling force system

The study of a gundrilling force system is fundamental to most of the gundrilling research. This paper addresses the effects of single flute gundrill geometry on the force system through relevant theories and experiments. Major findings include the following. Firstly, net torque or thrust force increases with the angular width of a wear pad or coefficient of friction and burnishing. Secondly, hydrodynamic pressure on outer diameter (OD) relief reduces net torque to some degree that depends on the radial clearance (c) of OD relief and the projected length thereof. However, the dependency on c may significantly weaken after c has reached a saturation value.