Clamp mechanism of cutting insert, cutting tool, cutting insert, and clamp member

A clamp mechanism for removably attaching a cutting insert (1) to a cutting tool (10), comprising;

• a clamp member (20) for fixing the cutting insert (1) to the cutting tool (10), the clamp member (20) being movable forward/backward along a predetermined restraining direction (C1), wherein
• the cutting tool (10) is provided with a first guide face (11) for guiding the cutting insert (1) in a predetermined guide direction (A) not parallel to the restraining direction (C1),
• a first member of the clamp member (20) and the cutting insert (1) is provided with a plug element (24) extending from a main section thereof and a second member of the clamp member (20) and the cutting insert (1) is provided with a concave portion (5) extending therein, and
• the plug element (24) and the concave portion (5) respectively include, in at least a cross section, a swollen section (24a, 5a) having a first dimension in the width direction, and a narrow section (24b, 5b) disposed in an area closer to the main section of the first member than the swollen section (24a, 5a) and having a second dimension smaller in the width direction than the first dimension, wherein
• the narrow section (5b) of the concave portion (5) interferes with the swollen section (24a) of the plug element (24) to suppress separation of the cutting insert (1) in the guide direction (A) from the clamp member (20).