Abstract: A drill bit (1) has a central axis (A) and a tapered cutting end part (2 ) terminating in a drill tip (3) at one end of the drill bit (1), a shank (4) extending from an opposing end of the drill bit (1), and a body (4a) extending between the cutting end part (2) and the shank (4). A plurality of flutes (5) are formed in the drill bit (1) and helically extend along the body (4a) into the cutting end part (2). Each flute (5) has a flute leading side wall (6) and a flute trailing side wall (7). A land (9) is defined on the body (4a) between each of the flutes (5) and extends to the cutting end part (2). In any body cross-sectional plane extending perpendicular to the central axis (A) through the body (4a), a land leading edge region (11) of each land (9) adjoining the flute trailing side wall (7) of a leading adjacent flute (5) is convexly curved.

Abstract: A drill bit (1) has a tapered cutting end part (2) terminating in a drill tip (3), a shank (4) and a body (4a) extending between the cutting end part (2) and the shank (4). A plurality of flutes (5) are formed in the drill bit (1) and generally helically extend along the body (4a) into the cutting end part (2) to adjacent the drill tip (3). Each flute (5) has a flute leading side wall (6) and a flute trailing side wall (7). A land (9) is defined on the body (4a) between each of the flutes (5) and extends to the cutting end part (2). Each land (9) defines a secondary edge (11) with the flute trailing side wall (7) of the leading adjacent flute (5). Each secondary edge (11) helically extends to the cutting end part (2) at a secondary edge helix angle. A plurality of tip faces (14) are defined on the cutting end part (2) and each extend from one of the lands (9) to the drill tip (3). The tip faces (14) are separated by the flutes (5) up to adjacent the drill tip (3).

Abstract: A drill bit (1) has a central axis (A) and comprises a tapered cutting end part (2) terminating in a drill tip (3) at one end of the drill bit (1), a shank (4) extending from an opposing end of the drill bit (1), and a body (4a) extending between the cutting end part (2) and the shank (4). A plurality of flutes (5) are formed in the drill bit (1) and helically extend along the body (4a) into the cutting end part (2). Each flute (5) has a flute leading side wall (6) and a flute trailing side wall (7). A land (9) is defined on the body (4a) between each of the flutes (5) and extends to the cutting end part (2). In any body cross-sectional plane extending perpendicular to the central axis (A) through the body (4a), a land leading edge region (11) of each land (9) adjoining the flute trailing side wall (7) of a leading adjacent flute (5) is convexly curved.

Abstract: A drill bit (1) having a central axis (A) has a tapered cutting end (2) part terminating in a drill tip (3) at one end of the drill bit (1) and a shank (4) extending from an opposing end of the drill bit (1). A plurality of flutes (5) are formed in the drill bit (1) and helically extend from adjacent the shank (4) into the cutting end part (2). Each flute (5) has a flute leading side wall (6) and a flute trailing side wall (7) and a land (9) defined between each of the flutes (5) and extending to the tapered cutting end part (2). Each land (9) has a leading land margin (10) defining a secondary cutting edge (11) with the flute trailing side wall (7) of a leading adjacent flute (5). Each land (9) also has a land relief (12) extending from the land margin (10) toward a trailing adjacent flute (5). Each land (9) still further has a land transition region (12) blending the land relief (12) into the flute leading side wall (6) of the trailing adjacent flute (5).