CBN INSERT WITH BREAKER

摘要

Provided is a long-life cutting insert, which can improve a chip treatment and a reliable control of the chip flowing direction even in the case of a work profile-finishing lathe-turning treatment. The periphery of a corner portion (C) of a cutting blade (5) to be formed in an insert body (1) is formed of a cBN sintered body (9B). In the corner portion (C), a chamfered portion (6) is formed along the cutting blade (5). In this chamfered portion (6) at the corner portion (C), there is formed a chip breaker (10), which is equipped with a breaker bottom face (10A) directed to the side of a cutting face (2) of the cutting blade (5), and a breaker wall face (10B) rising with respect to the breaker bottom face (10A). In the portion facing the corner portion (C), the chip breaker (10) is formed at its breaker wall face (10B) into either a convex face curved along a convex line formed by the corner portion (C) or a multiple step shape of five or more steps.