Abstract: This invention has to do with a rotary twist drill of the type having a fluted cylindrical shank with a drill bit end having at least two cutting edges extending radially outwardly from the longitudinal axis of the drill. Cutting edges are formed by the intersection of the flutes with the drill point end and extend radially outwardly from the center of the drill body to the outer perimeter of the drill body. Gashes formed on the drill point end form innermost cutting edge portions which are symmetrical with one another about a point offset both horizontally and vertically from the axial centerline of the drill body so as to allow a positive cutting action at the centerline of the material to be removed.

Abstract: A new chip breaking end mill is disclosed having an elongate cylindrically shaped body with opposing shank and cutter ends wherein at least one flute is spirally formed around the center axis of the cylindrically shaped body and the flute extends axially from the shank end to the cutting end. A cutting edge is formed by the intersection of the flute with the outer diameter of the cylindrically shaped body and extends longitudinally of the cylindrically shaped body. A concave, facing outwardly, chip breaker groove is formed in the flute and located adjacent to the cutting edge and the groove extends axially along with the cutting edge on the cylindrically shaped body. A chip guide channel is located adjacent to, and on the other side of the chip breaker groove than the cutting edge and it also extends axially along the length of the body. A longitudinally extending raised intersection is formed between the adjacent chip breaker and chip guide.

Abstract: This invention has to do with a rotary twist drill of the type having a fluted cylindrical shank with a drill bit end having at least two cutting edges extending radially outwardly from the longitudinal axis of the drill. Cutting edges are formed by the intersection of the flutes with the drill point end and extend radially outwardly from the center of the drill body to the outer perimeter of the drill body. Gashes formed on the drill point end form innermost cutting edge portions which are symmetrical with one another about a point offset both horizontally and vertically from the axial centerline of the drill body so as to allow a positive cutting action at the centerline of the material to be removed.