Patent ID: 8475089

Claim:
An indexable milling insert for milling tools, comprising: a bottom surface; an opposite chip surface; a plurality of side surfaces extending between the bottom surface and the opposite chip surface, two of the side surfaces being primary clearance surfaces and two of the side surfaces being secondary clearance surfaces; a plurality of cutting edges formed between the opposite chip surface and the primary and secondary clearance surfaces, wherein two cutting edges that connect to the primary clearance surfaces are primarily parallel and constitute main cutting edges; at least one lock structure comprising a locking surface arranged on one of the secondary clearance surfaces so that the locking surface and the primary clearance surface form an acute angle, α, in a section that is parallel to the bottom surface and intersects the locking surface; and a coupling structure arranged on the opposite chip surface and at least partly projecting from a plane that is parallel to the bottom surface and passes through points of the main cutting edges situated closest to the bottom surface, wherein the coupling structure comprises at least one flank surface, which is arranged such that the flank surface, in a section that is parallel to the primary clearance surface and intersects the flank surface, forms an acute angle β with the bottom surface so that the flank surface slopes in a direction from the secondary clearance surface on which the locking surface is arranged.