A cutting insert holder assembly for chip-removing machining, comprising a blade-shaped insert holder formed of a first material, and an insert manufactured from a different, harder material;
- said insert being mountable in an outwardly opening slot of the holder;
- said slot extending in a longitudinal direction and being defined between a stiff base portion of the holder and an elastically flexible clamping arm of the holder;
- said insert engaging said clamping arm and said base portion to form respective interfaces, at least one of the interfaces including a male part and a female part;
- said male part being generally V-shaped in cross-section and having a pair of laterally separated, first contact surfaces extending at a first obtuse angle relative to each other;
- said female part being generally V-shaped in cross-section and having a pair of laterally separated, second contact surfaces extending at a second obtuse angle relative to each other to contact respective ones of said first contact surface when said insert is inserted into said slot;
- the improvement wherein:
- one of said male part and said female part including, between the respective pair of contact surfaces thereof, a ridge;
- the other of said male part and said female part including, between the respective pair of contact surfaces thereof, a flute for receiving said ridge;
- said ridge including two ridge side surfaces interconnected by a top surface, said ridge side surfaces forming a first acute angle between one another;
- said flute including two flute side surfaces interconnected by a bottom surface, said flute side surfaces extending at a second acute angle relative to one another;
- said ridge having a height shorter than a depth of said flute to form a first gap between said top surface and said bottom surface;
- a transition formed between each of said contact surfaces and a respective one of said side surfaces, said transitions on said male part being spaced from respective transitions on said female part to form second gaps;
- a nominal width of said ridge defined by said ridge side surfaces being shorter than a nominal width of said flute defined by said flute side surfaces to form third gaps between said ridge side surfaces and said respective flute side surfaces;
- said insert holder being deformable in response to a transverse load being applied to said insert transversely of the longitudinal direction sufficiently to close one of said third gaps to create three-point contact between the insert and the holder, the three-point contact defined by
- contact between one of the first contact surfaces and one of the second contact surfaces,
- contact between the other of the first contact surfaces and the other of the second contact surfaces, and
- contact between the ridge side surface and the,,flute side surface which defines the closed third gap.