DRILLING INSERT Russian patent published in 2015 - IPC B23B51/00 

FIELD: process engineering.

SUBSTANCE: claimed insert has top surface, bottom surface and peripheral side surface to connect said top and bottom surfaces, and cutting edge made at transition between said top and bottom surfaces. Said cutting edge is configured to form N identical cutting angles and N identical partial cutting edges extending between two cutting angle at N ∈ {3, 4}. Each of said N partial cutting edges has the major cutting edge. The latter abuts on the first cutting angle and is straight if top surface is viewed from above. The minor cutting edge abuts on the second cutting angle and is straight if top surface is viewed from above. Said transition makes said major and minor cutting edges conjugate. Said transition has bulged part abutting on the major cutting edge and recessed part abutting of the minor cutting edge (12). Major cutting edge (10) and minor cutting edge form on outer side the angle α<180° in top surface plan form.

EFFECT: higher machining precision.

14 cl, 10 dwg