Face milling insert
A face milling insert comprising a pair of main cutting edges which are spaced apart from a center and meet at a corner where they transform into a surface wiping secondary edge, which is intersected by a bisector defining the corner between the main cutting edges, inside each main cutting edge a slope surface being formed, which slopes towards a countersunk bottom surface in a chip surface. A shoulder, having a top side situated at a higher level than the bottom surface, extends inwardly from the secondary edge, the slope surface of the main cutting edge that actively co-operates with the secondary edge, terminating at the shoulder.
1. A positive face milling insert, comprising:
a top side serving as a chip surface, a bottom side, a number of clearance surfaces therebetween, and a pair of chip-removing main cutting edges which are spaced apart from a center of the insert and meet at a corner where they transform into a surface wiping secondary edge, which is intersected by a bisector defining said corner between the main cutting edges, a rake surface along each main cutting edge sloping towards a countersunk bottom surface, and each clearance surface forming an acute angle with the top side so as to give the insert its positive geometry,
wherein a shoulder, having a certain thickness, protrudes from the bottom surface and rake surface, said shoulder having a top surface which extends inwardly from the secondary edge along the bisector and transforms into each rake surface via a leaning side transition surface providing the level difference between said top and rake surfaces and forming a termination of the rake surface.
2. The face milling insert according to claim 1 , wherein a width of the shoulder in proximity of the secondary edge is substantially as large as a length of said secondary edge.
3. The face milling insert according to claim 1 , wherein said main cutting edges and secondary edges are located in a common plane to or over which said shoulders project.
4. The face milling insert according to claim 1 , wherein a width of the top side in the direction of the center of the shoulder successively increases from the secondary edge.
5. The face milling insert according to claim 1 , wherein the top surface of the shoulder is planar and parallel to the top side of the insert.
6. The face milling insert according to claim 1 , wherein at least a part of the top surface is leaning in the direction inward/upward from the secondary edge.