Patent ID: 9004825
Filing Date: 2015-04-14
Classification: B23B,Y10T

Abstract:
1. A multiple edge drill comprising: a point; and a main cutting edge having at least two main cutting edge sections and a buckle point, the at least two main cutting edge sections comprising a radial outer main cutting edge section and a radial inner main cutting edge section, the radial outer main cutting-edge section defining a radial outer tip angle, the radial inner main cutting edge section defining a radial inner tip angle, the radial outer tip angle being smaller than the radial inner tip angle, the radial outer tip angle in the range between 95 and 130°, the radial inner tip angle in the range between 130 and 150°, the buckle point lying between the two main cutting edge sections and having a distance from the drill axis in the range greater than 0.25 and up to 0.35×D, D designating the nominal diameter of the drill.