A tool for chip removing machining, including a basic body, in which at least one seating is included, which is delimited by a base surface and a rear support protruding in relation to the base surface, the base surface including a first coupling section in the form of one or more ridges and grooves, and a replaceable cutting insert having an upperside, an underside and a clearance surface extending between the upperside and the underside and transforming into the upperside via at least one cutting edge, the underside including a second coupling section having one or more grooves and ridges which engage the grooves of the first coupling section, and vice versa, at the same time as a part of the clearance surface is urged against the rear support. An imaginary extension of the ridges of the first coupling section extends by the side of the rear support.