Patent attributes
A drill for chip removing machining, including a drill body, and a replaceable cutting insert mounted in a pocket formed in a front tip of the drill body. A chip flute extends backwardly from the pocket along the drill body, and the cutting insert is fixed in the pocket by a screw including a head and a shank having a male thread. The cutting insert includes a through hole extending between a topside and an underside. The hole has a basic shape that is rotationally symmetrical in relation to a center axis, and is delimited by a series of surfaces including a mouth surface, converging downward from the topside, and a shoulder surface. The head of the screw is kept pressed against the shoulder surface when the male thread of the screw is tightened in a female thread included in a hole that mouths in a bottom of the pocket. The mouth surface in the hole of the cutting insert has a trumpet-like, cross section-wise convex shape adjacent to the topside of the cutting insert.
