Drilling tool for metallic materials

Drilling tool for metallic materials, comprising a holder (1) having an axial clamping slot (4) in which a plate-shaped drilling blade (2) is inserted to bear against the base surface (9) of the clamping slot (4) and is clamped against a limb (8) of the clamping slot by means of a threaded pin (3), which is provided with a head (21) and which engages in a bore (15) in the drilling blade (2) and in a bore (12) in said limb (8) of the clamping slot, wherein the center axis (13) of the bore (12) in said limb (8) of the clamping slot is offset relative to the center axis (24) of the bore (15) of the drilling blade (2) and at least one of two mutually facing circumferential edges (16, 22) of the head (21) of the threaded pin (3) and the bore (15) of the drilling blade is bevelled, and further comprising a centering pin (11;

• 11a) which is inserted in the holder (1) and engages in a centering slot (18) in that side (17) of the drilling blade (2), which is contacting the base surface (9) of the clamping slot (4), so as to center the drilling blade (2) with respect to the rotational axis (6) of the holder (1), characterized in that the nominal width of the centering slot (18) is selected to be greater than that of the portion of the centering pin (11;
• 11a) engaging in the centering slot (18) and that the direction and amount of the offset of the central axes (13, 24) of the bore (15) of the drilling blade and bore (12) of the limb of the clamping slot are so selected that in the tightened state of the threaded pin (3) only one side face (20) of the centering slot (18) bears on one side of the centering pin (11;
• 11a) in the centered position of the drilling blade (2).