Patent attributes
In an end view, a cutting insert 10 comprises a first connecting part 30A which is inclined such that the first connecting part 30A travels in a first direction as it heads away from a second peripheral side surface part 18 and approaches a fourth peripheral side surface part 22, and also comprises a second connecting part 30B which is connected to a center point serving as an end of the first connecting part 30A and which is inclined such that the second connecting part 30B travels in a third direction as it heads away from the second peripheral side surface part 18 and approaches the fourth peripheral side surface part 22. A cutting edge 24 comprises: a first cutting edge part 24A which is formed on the first connecting part 30A so as to be distant, by a first distance L1, from a virtual plane PR1 including a center point C1; a second cutting edge part 24B which has, in a side view, a concave circular-arc shape having a second curvature radius smaller than a first curvature radius and which is formed on the second connecting part 30B so as to be distant, by a second distance L2 greater than the first distance L1, from the virtual plane PR1; and a third cutting edge part 24C connecting the first cutting edge part 24A and the second cutting edge part 24B.