Cutting insert and cutting tool therewith

A cutting tool, comprising:

• a tool body including at least one seating surface and a threaded hole extending in a direction away from the seating surface;
• at least one cutting insert removably secured on the seating surface, the at least one cutting insert having a mounting hole passing therethrough;
• and
• a screw passing through the mounting hole and being fastened to the threaded hole to thereby removably secure the cutting insert to the tool body;
• wherein the threaded hole is slanted with respect to the seating surface,
• wherein a wall surface of the mounting hole contacts a head of the screw about at least one first contact portion and at least one second contact portion, the at least one first contact portion being formed at a level different from that of the at least one second contact portion along a longitudinal axis of the mounting hole, a contact angle at the at least one first contact portion and a contact angle at the at least one second contact portion being different from each other.