Patent ID: 7677845
Filing Date: 2010-03-16
Classification: B23B,Y10S,Y10T

Abstract:
1. A drill for chip removing machining, comprising: a drill body, and a replaceable cutting insert mounted in a pocket formed in a front tip of the drill body, a chip flute extending backwardly from the pocket along the drill body, and the cutting insert being fixed in the pocket by a screw including a head and a shank having a male thread, the cutting insert including a through hole extending between a topside and an underside, the hole having 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 being 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, wherein 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.