Mounting mechanism for a cutting insert, a cutting insert therefor and a cutting tool using said insert

A cutting tool holder adapted for mounting thereon a cutting insert having a top face, a bottom face, and an insert bore extending between said top face and said bottom face, the insert bore having an inner surface, said cutting tool holder comprising:

• a seat defined by a base surface and at least one side wall angled to said base surface;
• a seat bore extending along a bore axis, the seat bore having an open end at said base surface;
• and
• a securing arrangement including:
• a securing member extending between a proximal end and a distal end, the securing member having a head portion at said proximal end and having said distal end received within said seat bore, and
• a displacement arrangement adapted to displace the securing member along the bore axis of said seat bore between a mounting position in which said head portion protrudes from within the seat bore through said base surface into said seat to a first extent, defining a first gap distance between said head portion and said at least one side wall allowing said cutting insert to be placed within the seat and/or being fully removed from the seat, and a securing position in which said head portion protrudes from within the seat bore through said base surface into said seat to a second extent, smaller than said first extent, defining a second gap distance between said head portion and said at least one side wall smaller than said first gap distance, so as to engage the inner surface of said insert bore, thereby securing said cutting insert between the head portion and the at least one side wall;
• wherein said insert seat is further formed with a support surface configured for engaging and providing support to the head portion of said securing member at least in said securing position, the support surface comprising a surface of a support structure extending from the base surface into said seat.