An indexable cutting insert for an end mill tool, the cutting insert comprising: • a lower surface configured to be supported by a support face of a pocket of a tool body of the end mill tool, • a top surface, and • a peripheral side surface connecting the lower surface and the top surface, • the cutting insert having a hexagonal basic shape as seen perpendicularly to the top surface with two straight long sides (12, 13) and two v-shaped short sides(14, 15), the cutting insert being double-sided in the sense that the lower and top surfaces (8, 10) thereof are identical and a cutting edge portion is formed at the intersection of each of these surfaces with the peripheral side surface of the insert along each v-shaped short side (14, 15), in which each cutting edge portion comprises: • a first corner edge forming a front cutting tip on the v-shaped short side, whereby the corner edge is projecting furthest in the direction of an axis of rotation of said end mill tool in a state of use, • a major cutting edge extending from said first corner edge in a first direction on the v-shaped short side and descending to come closer to the lower surface of the insert along its extension away from the first corner edge, whereby the major cutting edge is extending outward to a second corner edge located at an outer corner of the end mill tool in the state of use, and • a first minor cutting edge extending from the first corner edge in a second direction on the v-shaped short side, opposite to the first direction of the major cutting edge, whereby the first minor cutting edge is extending towards an inner corner of the insert in the state of use, characterized in that the four first corner edges are intersected by a symmetry plane dividing the insert into two equal parts and being perpendicular to the lower and top surfaces (8, 10), and in that the first minor cutting edge extends from said first corner edge while descending from a point of the cutting edge portion most distant to the lower surface all the way to the inner corner of the insert and has a length of 80%-95% of the length of the major cutting edge including the second corner edge in a side view of the insert. • a lower surface configured to be supported by a support face of a pocket of a tool body of the end mill tool, • a top surface, and • a peripheral side surface connecting the lower surface and the top surface, • the cutting insert having a hexagonal basic shape as seen perpendicularly to the top surface with two straight long sides (12, 13) and two v-shaped short sides(14, 15), the cutting insert being double-sided in the sense that the lower and top surfaces (8, 10) thereof are identical and a cutting edge portion is formed at the intersection of each of these surfaces with the peripheral side surface of the insert along each v-shaped short side (14, 15), in which each cutting edge portion comprises: • a first corner edge forming a front cutting tip on the v-shaped short side, whereby the corner edge is projecting furthest in the direction of an axis of rotation of said end mill tool in a state of use, • a major cutting edge extending from said first corner edge in a first direction on the v-shaped short side and descending to come closer to the lower surface of the insert along its extension away from the first corner edge, whereby the major cutting edge is extending outward to a second corner edge located at an outer corner of the end mill tool in the state of use, and • a first minor cutting edge extending from the first corner edge in a second direction on the v-shaped short side, opposite to the first direction of the major cutting edge, whereby the first minor cutting edge is extending towards an inner corner of the insert in the state of use,