| 摘要 |
A twist drill, having a replaceable drill tip, comprising a drill bit shaft ( 1 ), a cutting insert ( 2 ) which is detachably fixed thereto and which forms the tip area of the twist drill, and comprises a flute ( 3 ) that continues into the cutting insert ( 2 ). The cutting insert rests, with a bearing surface ( 6 ) extending orthogonal to the center longitudinal axis ( 8 ) of the drill bit, on the face ( 7 ) of the drill bit shaft ( 1 ) and extends with a fixing stud ( 9 ), which centrally protrudes from the bearing surface ( 6 ), into a receiving recess ( 10 ) which is configured complementary thereto and which is provided in the face ( 7 ) of the drill bit shaft ( 1 ). At least one peripheral section ( 13 ) of the fixing stud ( 9 ) comprises a first longitudinal section ( 15 ) that, with a screw surface ( 16 ) which points away from the drill bit shaft ( 1 ), which slopes upward to the drill bit tip ( 5 ) in a direction of rotation of the drill bit, and which interacts with an opposite surface ( 19 ) on the inner wall ( 14 ) of the receiving recess ( 10 ), merges into a second longitudinal section ( 17 ).
|
