Patent attributes
The purpose of the present invention is to provide a cutting insert capable of reducing cutting load and enhancing squareness. A cutting insert, according to one embodiment of the present invention, comprises: first and second end surfaces which face opposite directions to each other and have four corners wherein two ascending corners are placed in one diagonal position, and two descending corners lower than the height of the ascending corners are placed in the remaining diagonal position; first and second main side surfaces which are placed between the first and second end surfaces, face in opposite directions to each other, and have a throughhole connecting the first and second main side surfaces to each other; and first and second auxiliary side surfaces placed between the first and second end surfaces and between the first and second main side surfaces, wherein, when seen from the first or second end surface, each of the first and second main side surfaces comprises: a central main clearance surface placed on a central portion thereof; a first peripheral main clearance surface which is placed between the central main clearance surface and the ascending corners, and which forms an obtuse angle with respect to the central main clearance surface such that the central main clearance surface may protrude; and a second peripheral main clearance surface which is placed between the central main clearance surface and the descending corners, and forms an obtuse angle with respect to the central main clearance surface such that the central main clearance surface may protrude.