A twist drill comprising a shank section at a top of the drill and a body section at a bottom of the drill, the body section having two or more flutes which spiral downwardly in a first direction and terminate proximate a point, the drill having cutting lips formed by the flutes and operatively...http://www.google.se/patents/US5685673?utm_source=gb-gplus-sharePatent US5685673 - Twist drill with reverse flutes
