Patent ID: 8070399

Claim:
A drill point ( 1 ) for drilling sandwich panels ( 100 ), composite materials and similar, comprising: a shank ( 2 ) for coupling into the chuck a tool apt to drive said point ( 1 ) in rotation; a drilling member, integral to said shank, comprising: a substantially cylindrical working portion ( 3 ), a cutting head ( 4 ), located at the end of said working portion ( 3 ), having cutting edges (C); wherein onto the surface of said working portion ( 3 ) there are obtained helical flutes ( 5 ), spirally arranged about a substantially central longitudinal axis (A-A) of said working portion ( 3 ), said flutes ( 5 ) ending on a top face ( 4 â€²) of said cutting head ( 4 ), characterized in that the constructive geometry thereof provides: a helix angle (Îµ) with respect to said longitudinal axis (A-A), along which there develop said helical flutes ( 5 ), substantially comprised in a range of 30Â° to 35Â°; a chisel edge angle (Î·) substantially comprised in a range of 1Â° to 5Â°; a first radial relief angle (Î³ r ) substantially of 7Â°; a second external relief angle (Î±) substantially comprised in a range of 22Â° to 26Â°; an inferior relief angle (Î´) of said helical flutes ( 5 ) on said cutting head ( 4 ) with respect to said longitudinal axis (A-A) substantially of about 25Â°; a section of said cutting head ( 4 ), commonly known as face ( 6 ), for raising and letting flow a chip deriving from the drilling action, having length (L 6 ) substantially comprised in a range of 0.3 to 0.5 mm; an angle (Î¸) included between said face ( 6 ) and the relief ( 7 ) of said flutes ( 5 ) on said head ( 4 ) substantially comprised in a range of 70Â° to 80Â°; a central core ( 8 ) of said point ( 1 ) with diameter (D 8 ) substantially comprised in a range of 1.5 mm to 2.7 mm; a sharpening angle (Î²) of the head ( 4 ) of said point ( 1 ) substantially comprised in a range of 110Â° to 150Â°; so as to carry out a one-shot drilling of said sandwich panels ( 100 ), composite materials and similar.