Patent ID: 8206066

Claim:
A double-sided cutting insert ( 18 , 118 ) for retention in a rotating cutting tool having an axis of rotation, the cutting insert comprising: two opposing end surfaces ( 28 , 128 ) and a peripheral surface ( 26 ) extending therebetween, each end surface having a mutual first axis of symmetry (B) passing through the end surfaces about which each end surface has N-fold rotational symmetry, where N is a number from the group consisting of 2, 3 and 4; a peripheral cutting edge ( 66 , 166 ) formed at the junction between each end surface and the peripheral surface, the peripheral cutting edge comprising N curved cutting edges ( 32 , 34 ; 132 , 134 ) merging with N straight cutting edges ( 44 , 50 ; 144 , 150 ) which extend between the curved cutting edges at extremities thereof; wherein: the curved cutting edges of the two end surfaces are not aligned, as seen in an end view of the cutting insert: and each of the N curved cutting edges ( 32 , 34 ; 132 , 134 ) lies on a torus and extends along an angle equal to or larger than 120°, as seen along the first axis of symmetry (B).