A metal cutting tool includes a holder arrangement, an indexible cutting insert seated on an insert-receiving site of the holder arrangement, and a screw for fastening the insert to the site. The bottom side of the insert includes more than two upright abutment surfaces arranged to abut respective upright support surfaces of the site, whereby the areas of contact formed by the mutually abutting surfaces lie inside of an outer perimeter of the insert. The abutment surfaces are oriented non-parallel to one another. The screw is arranged to urge the insert in a direction whereby less than all of the abutment surfaces abut respective support surfaces, and at least one abutment surface does not abut a support surface. When the insert is indexed, the non-abutting abutment surface is relocated and caused to abut a support surface when the screw is tightened, while an abutment surface that previously abutted a support surface becomes a non-abutting surface.