Drilling with flat rake face and conventional twist drills—I. Theoretical investigation

A cutting analysis, based on oblique cutting models, is developed for the drill lips of flat rake face (modified) drills. The analysis predicts reasonable deformation and force distributions along the drill lips. An analysis for conventional drills is also attempted with less success. The concept of geometrical similarity is studied and shown to be useful for prediction of forces in drilling and for the design of twist drills.