A cutting insert having an insert longitudinal axis (A IL) and comprising opposing insert top and bottom surfaces (14A, 14B), opposing insert first and second end surfaces (14C1, 14C2) extending transverse to the insert longitudinal axis (A IL), each end surface connected to the insert top and bottom surfaces (14A, 14B), opposing insert first and second side surfaces (14D1, 14D2) extending along the insert longitudinal axis (A IL), each side surface connected to the insert top and bottom surfaces (14A, 14B) and to the insert first and second end surfaces (14C1, 14C2), an insert first intersection (14G1) defined at an intersection of the insert top surface, the insert first end surface (14C1) and the insert first side surface (14D1), an insert second intersection (14H1) defined at an intersection of the insert top surface, the insert first end surface (14C1) and the insert second side surface (14D2), a cutting edge (14F1) extending from the insert first intersection (14G1) to the insert second intersection (14H1), and an insert aperture opening out to the insert top and bottom surfaces (14A, 14B); the insert aperture comprising opposing aperture first and second side surfaces (32A1, 32A2) extending along the insert longitudinal axis (A IL), and opposing aperture first and second end surfaces (32B1, 32B2) extending transverse to the insert longitudinal axis (A IL), and each being connected to the aperture first and second side surfaces (32A1, 32A2); wherein, in a plan view of the insert top surface, the cutting insert and the insert aperture both have oblong shapes which are elongated along the insert longitudinal axis (A IL); wherein at least one of the aperture first and second end surfaces (32B1, 32B2) is formed with a clamping lip (32C1, 32C2); characterised in that each of the aperture first and second side surfaces (32A1, 32A2) is devoid of a clamping lip. opposing insert top and bottom surfaces (14A, 14B), opposing insert first and second end surfaces (14C1, 14C2) extending transverse to the insert longitudinal axis (A IL), each end surface connected to the insert top and bottom surfaces (14A, 14B), opposing insert first and second side surfaces (14D1, 14D2) extending along the insert longitudinal axis (A IL), each side surface connected to the insert top and bottom surfaces (14A, 14B) and to the insert first and second end surfaces (14C1, 14C2), an insert first intersection (14G1) defined at an intersection of the insert top surface, the insert first end surface (14C1) and the insert first side surface (14D1), an insert second intersection (14H1) defined at an intersection of the insert top surface, the insert first end surface (14C1) and the insert second side surface (14D2), a cutting edge (14F1) extending from the insert first intersection (14G1) to the insert second intersection (14H1), and an insert aperture opening out to the insert top and bottom surfaces (14A, 14B); opposing aperture first and second side surfaces (32A1, 32A2) extending along the insert longitudinal axis (A IL), and opposing aperture first and second end surfaces (32B1, 32B2) extending transverse to the insert longitudinal axis (A IL), and each being connected to the aperture first and second side surfaces (32A1, 32A2);