Patent ID: 8801344

Claim:
Drill bit with at least one main cutting edge ( 3 , 3 ′) and at least one center cutting edge ( 15 , 15 ′), wherein the drill bit ( 1 ) has a longitudinal axis ( 13 ) and wherein a rake face ( 7 , 7 ′; 11 , 11 ′) is assigned-to the at least one main cutting edge ( 3 , 3 ′) and at least one center cutting edge ( 15 , 15 ′), characterized in that: the rake face ( 11 , 11 ′) assigned to the at least one center cutting edge ( 15 , 15 ′) has at least two partial faces ( 19 , 19 ′; 21 ; 21 ′; 41 ; 41 ′) that—seen perpendicular to the longitudinal axis ( 13 ) of the drill bit ( 1 )—form an obtuse angle with each other so the at least one center cutting edge ( 15 , 15 ′) comprises at least two partial cutting edges ( 23 , 23 ′; 25 , 25 ′; 43 , 43 ′), and a front rake angle is assigned to the one main cutting edge ( 3 , 3 ′) and the at least two partial cutting edges ( 23 , 23 ′; 25 , 25 ′; 43 , 43 ′) of the center cutting edge ( 15 , 5 ′), wherein the front rake angle has a value that increases with increasing radial distance of the assigned main cutting edge and/or partial cutting edge ( 3 , 3 ′; 23 , 23 ′; 25 , 25 ′; 43 , 43 ′) with respect to the longitudinal axis of the drill bit ( 1 ).