Cutting tool, cutting tool holder and cutting insert therefor

A cutting insert configured for mounting onto a cutting tool holder to form the cutting tool, the cutting tool holder including comprising:

• an insert seat space configured for receiving therein the cutting insert, the insert seat space being defined by a base and at least one side wall extending from the base to define an insert seat space adapted for receiving the cutting insert;
• a support element fixedly and integrally formed with the base and extending therefrom into the insert seat space;
• a fastening member;
• and
• a bore formed in the insert seat configured for receiving a fastening member for engagement with the insert seat;
• a support element extending into the insert seat from the base so that the bore is disposed between the side wall and the support element, and being one of the following:
• integrally formed with said insert seat;
• or at least during operation, fixedly attached to the insert seat by means other than the fastening member open at the base to the insert seat space adjacent the support element and between said side wall and said support element, and configured for receiving the fastening member for engagement therewith, the bore being;
• and the fastening member, when received within the bore, being displaceable with respect to the insert seat base between a mounting position configured for allowing the cutting insert to be mounted onto within the insert seat space and a securing position adapted for securing the cutting insert within the insert seat, space;
• the fastening member, in the securing position, being configured to engage a sidewall of the support element and apply on the cutting insert a biasing force, directed away from the support element and towards the side wall defining the insert seat space, thereby securing the cutting insert within said insert seat space;
• the cutting insert comprising:
• a top face;
• a bottom face;
• and
• a cavity extending between the top face and the bottom face, the cavity taking up no less that than 15% of the overall volume of the cutting insert, the cavity defining a central axis extending between the top face and the bottom face through the center of an inscribing circle of the cavity, located on a plane substantially perpendicular to the axis, the cavity being formed with an inner surface having a first securing portion with a first geometric shape configured for engagement with the support element, and a second securing portion located at an opposite side of the cavity with respect to the central axis, and having a second geometric shape configured for engagement with the fastening member, both the first and the second securing portion being configured for simultaneously engaging the respective support element and fastening member in the same mounting position.