УДК 621.9.02 © Galina Nikolcheva, Ivo Likov MATHEMATICAL MODEL FOR MODIFIED CONICAL DRILL POINT A new drill point geometry, termed modified conical drill point is developed. <...> The relationship between the desired conical drill point geometry and grinding parameters for a modified conical drill point grinder are described. <...> The characteristics of the grinding parameters for determining the grinding parameters as well as guiding the new grinder design have been analyzed. <...> The drill point geometry uniquely defined by the shapes of the flute and of the flank surfaces. <...> As the flute configuration is designed by the manufacture, the drill flank configuration becomes the major factor when attempting to improve the drill’s machining performance, in developing new drill geometry, as well as improving the accuracy and efficiency of the drill point grinding concerned by both the drill user and the manufacturer of the drill grinder. <...> The conical flank prof ile conf igures is the most commonly used drill point geometry, and is the easiest to grind. <...> After Galloway’s mathematical model, which describes the relationship between the point geometry and grinding parameters for the conical grinding method, several extended conical grinding models followed [1, 3, 6, 7, 10]. <...> There has been considerable works in the area of drill performance improvement by modifying the drill point geometry using flank surfaces: made up of multiple facets [9, 13], helical [8], cylindrical [2], split [11], planar [5], etc. <...> It may be noted that optimization is made only on the point grinding profile while the f lute grinding profile is constant and is assumed to follow the flute equation given by Galloway [4]. <...> Point C is the tip of the cone surface, which is formed on the drill flank surface. is the angle between the cone and drill axis. <...> OO1 ometry and grinding wheel for the proposed conical flank surface method are schematically illustrated in fig.1. <...> Used the face of grinding wheel, the drill holder is rotated about an axis CC1 tance h. <...> The position of point L is dependent on k* and it is determined so that the setting grinder, the drill <...>