| 摘要 |
An object of the invention is to provide a throwaway insert enabling the use of a holder for a long period and having excellent chip discharging property. The throwaway insert (1) is formed in a substantially polygonal plate shape and includes a rake face (2) formed on an upper surface thereof, a relief face (3) formed on a side surface thereof, a main cutting edge (4) formed along a ridge representing an intersection of the rake face (2) and the relief face (3), which is divided into a plurality of main cutting edge divisions (4a) by at least one groove (5) formed on the relief face (3), and a projection (6) formed so as to protrude from the rake face (2) in correspondence with each of the main cutting edge divisions (4). |
