Milling insert and a milling tool

An indexable milling insert for milling substantially perpendicular corners in a work piece, the milling insert including an upper side, a lower side, and edge surfaces extending between the upper and lower sides, the upper and lower sides being substantially identical, wherein an imaginary circle inscribed in the milling insert touches a periphery of the milling insert at between four to six points, wherein lines of intersection between the edge surfaces and the upper and lower sides form substantially perpendicular main cutting edges and associated minor cutting edges, each of the upper and lower sides each including a respective support surface, each support surface being provided in a respective plane, wherein at least an extension of each major cutting edge intersects the plane of an associated one of the support surfaces, and each associated minor cutting edge is disposed above the plane of the associated one of the support surfaces.