Cutting insert for a rotary milling cutter

A cutting insert for a rotary cutter tool, said insert being of substantially parallelepipedal shape, having a pair of opposite, parallel, major cutting edges of length L and a pair of opposite subsidiary cutting edges, each subsidiary cutting edge being transversely directed with respect to the major cutting edges and comprising at least two successive, angularly disposed, component subsidiary cutting edges, a first component cutting edge of each subsidiary cutting edge merging, via a rounded nose portion, with an adjacent end of a major cutting edge and defining therewith an angle .theta..sub.1 lying between 50.degree.-70.degree., a further component cutting edge of each subsidiary cutting edge merging with an adjacent end of an opposite major cutting edge and defining therewith an angle .theta..sub.2 lying between 20.degree.-40.degree.;

• the total projected length of the component subsidiary cutting edges of each subsidiary cutting edge being approximately 0.61 L, wherein the component cutting edges are respectively associated with negative land surfaces.

A cutting insert for a rotary cutter tool having a longitudinal rotary cutting axis, said insert being of substantially parallelepipedal shape, having a pair of opposite peripheral cutting edges of length L and a pair of opposite frontal cutting edges, each frontal cutting edge being transversely directed with respect to the peripheral cutting edges and comprising at least two successive, angularly disposed, component cutting edges, a first component cutting edge of each frontal cutting edge merging, via a rounded nose portion, with an adjacent end of a peripheral cutting edge and defining therewith an angle .theta..sub.1 lying between 50.degree.-70.degree., a further component cutting edge of each frontal cutting edge merging with an adjacent end of an opposite peripheral cutting edge and defining therewith an angle .theta..sub.2 lying between 20.degree.-40.degree., the total projected length of the component cutting edges of each frontal cutting edge being approximately 0.6 L, wherein

• said insert is further adapted to be seated on said tool such that the insert's operative peripheral cutting edge is substantially co-directional with said axis and its operative frontal cutting edge is directed transversely to said axis.