| 摘要 |
A Drilling tool for metallic materials comprises a holder (1) having an axial clamping slot in which a plate-shaped drilling blade (2) is inserted and 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). The center axis (13) of the limb bore (12) is offset relative to the center axis (24) of the drilling blade bore (15). The mutually facing circumferential edges of the head (21) of the threaded pin and the bore (15) of the drilling blade is bevelled. A centering pin (11) 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) to center the drilling blade (2) with respect to the rotational axis (6) of the holder (1). For achieving a more exact centering the nominal width of the centering slot (18) is selected to be greater than that of the portion of the centering pin (11) engaging in the centering slot (18), while the direction and amount of the offset of the central axes (13, 24) of the bore (15) of the drilling blade and the bore (12) of the limb are selected such 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) in the centered position of the drilling blade (2).
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