US Patent 10150170 Insert and tool holder for mounting same

Provided is an insert for being mounted on a tool holder. The insert includes three substantially right-angled corners along a perimeter, a main cutting edge, a sub cutting edge, and a flat lower surface. A clearance angle of a second end main side surface forms an obtuse angle with respect to a lower surface, and a clearance angle of a second end sub side surface forms an obtuse angle with respect to the lower surface. A clearance angle of a first end main side surface forms a right angle with respect to the lower surface, and a clearance angle of a first end sub side surface forms a right angle with respect to the lower surface.