An indexable cutting insert (100, 100') having an insert longitudinal axis, an insert lateral axis and an insert vertical axis, the cutting insert (100, 100') comprising: two opposite insert end surfaces, and a peripheral surface extending therebetween; two opposite cutting portions (108, 110) and a clamping portion located therebetween, arranged along the insert longitudinal axis, wherein: each of the cutting portions (108, 110) comprises a rake surface, a front relief flank and two side relief flanks, with a cutting edge formed at an intersection of the rake surface and the front relief flank, the side relief flanks defining a first width; the clamping portion does not include the cutting edges, characterized in that it comprises: first and second side abutment surfaces (122, 123) extending between the two insert end surfaces, the first and second side abutment surfaces (122, 123) defining a second width, the second width being greater than the first width, two opposite elongated resilient beams with a flexibility aperture therebetween, the flexibility aperture opening out to the first and second side abutment surfaces (122, 123), each of the resilient beams is located between a respective one of the insert end surfaces and the flexibility aperture, the flexibility aperture being spaced apart from the cutting portions (108, 110), wherein the only resilient portions of the cutting insert (100, 100') are the two resilient beams. two opposite insert end surfaces, and a peripheral surface extending therebetween; two opposite cutting portions (108, 110) and a clamping portion located therebetween, arranged along the insert longitudinal axis, each of the cutting portions (108, 110) comprises a rake surface, a front relief flank and two side relief flanks, with a cutting edge formed at an intersection of the rake surface and the front relief flank, the side relief flanks defining a first width; the clamping portion does not include the cutting edges, characterized in that it comprises: first and second side abutment surfaces (122, 123) extending between the two insert end surfaces, the first and second side abutment surfaces (122, 123) defining a second width, the second width being greater than the first width, two opposite elongated resilient beams with a flexibility aperture therebetween, the flexibility aperture opening out to the first and second side abutment surfaces (122, 123), each of the resilient beams is located between a respective one of the insert end surfaces and the flexibility aperture, the flexibility aperture being spaced apart from the cutting portions (108, 110), wherein the only resilient portions of the cutting insert (100, 100') are the two resilient beams. first and second side abutment surfaces (122, 123) extending between the two insert end surfaces, the first and second side abutment surfaces (122, 123) defining a second width, the second width being greater than the first width, two opposite elongated resilient beams with a flexibility aperture therebetween, the flexibility aperture opening out to the first and second side abutment surfaces (122, 123), each of the resilient beams is located between a respective one of the insert end surfaces and the flexibility aperture, the flexibility aperture being spaced apart from the cutting portions (108, 110), wherein the only resilient portions of the cutting insert (100, 100') are the two resilient beams.