Twist drill for drilling having a replaceable drill tip, and a replaceable drill tip for use in a twist drill

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).