Four Plane Facet Point Drills - Basic Design and Cutting Model Predictions

Abstract

The Four Plane Facet Point drill popularly favoured for NC/CNC applications but seldom analysed in the research literature is investigated. A detailed analytical study of the design geometry, specification, point sharpening and predictive mechanics of cutting models for thrust, torque and power is presented. While the preferred method of specification for the "general" Facet Point geometry requires seven drill point features. six of which are commonly used in general purpose drill specifications, the "special" Facet Point design with the seventh feature set to zero degrees is proved to be the superior Facet Point design on the basis of point sharpening and drill performance criteria. The pre..