Cutting insert and milling cutter

1. A cutting insert comprising:

a top surface, a bottom surface, and a peripheral side surface extending therebetween, the peripheral side surface comprising a pair of opposing major side surfaces and a pair of opposing minor side surfaces;

two opposing major cutting edges formed at the intersection of the opposing major side surfaces with the top surface;

wherein each one of the pair of opposing major side surfaces comprises two spaced apart generally flat and non-coplanar abutment surfaces;

wherein a first of the two spaced apart abutment surfaces makes a first angle α with a normal N to a plane P passing through the bottom surface of the cutting insert and a second of the two spaced apart abutment surfaces makes a second angle β with the normal N; and

wherein each major side surface further comprises at least one upper relief surface disposed between the abutment surfaces and the major cutting edge, and forming a relief angle γ with the normal N.

2. The cutting insert according to claim 1 , wherein each major side surface further comprises at least one lower relief surface disposed between the abutment surfaces and the bottom surface.

3. The cutting insert according to claim 1 , wherein the cutting insert is provided with at least one through bore extending between the top and bottom surfaces.

4. A milling cutter comprising:

a cutter body having at least one insert pocket, the at least one insert pocket comprising adjacent side and rear walls generally transverse to a base, the side wall being provided with two spaced apart generally flat and non-coplanar side support surfaces, a forward side support surface and a rear side support surface, and

a cutting insert seated in the at least one insert pocket, the cutting insert comprising:

a top surface, a bottom surface, and a peripheral side surface extending therebetween, the peripheral side surface comprising a pair of opposing major side surfaces and a pair of opposing minor side surfaces;

two opposing major cutting edges formed at the intersection of the opposing major side surfaces with the top surface;

wherein;

each one of the pair of opposing major side surfaces comprises two spaced apart generally flat and non-coplanar abutment surfaces;

the two spaced apart generally flat and non-coplanar side support surfaces of the at least one insert pocket abut said two spaced apart generally flat and non-coplanar abutment surfaces belonging to one of said pair of opposing major side surfaces;

a first of the two spaced apart abutment surfaces makes a first angle α with a normal N to a plane P passing through the bottom surface of the cutting insert and a second of the two spaced apart abutment surfaces makes a second angle β with the normal N; and

the forward side support surface makes a third angle α′ with a normal N′ to a plane P′ passing through the base and the rear side support surface makes a fourth angle β′ with the normal N′.

5. The milling cutter according to claim 4 , wherein the third angle α′ is greater than the fourth angle β′.

6. The milling cutter according to claim 5 , wherein the first angle α is greater than the third angle α′ by a first angle difference δ 1 and the second angle β is greater than the fourth angle β′ by a second angle difference δ 2 .

7. The milling cutter according to claim 6 , wherein the first and second angle differences δ 1 , δ 2 are identical and equal to a given angle difference δ.

8. The milling cutter according to claim 7 , wherein the forward side support surface has an upper edge and the rear side support surface has an upper edge and wherein the upper edge of the forward side support surface abuts the first abutment surface of a given major side surface of the at least one cutting insert and the upper edge of the rear side support surface abuts the second abutment surface of the given major side surface of the at least one cutting insert.

9. The milling cutter according to claim 8 , wherein the first angle α is approximately 14°, the second angle β is approximately 5° and the given angle difference δ is approximately 0.5°.

10. The milling cutter according to claim 4 , wherein the forward side support surface has an upper edge and the rear side support surface has an upper edge and wherein the upper edge of the forward side support surface abuts the first abutment surface of a given major side surface of the at least one cutting insert and the upper edge of the rear side support surface abuts the second abutment surface of the given major side surface of the at least one cutting insert.

11. A cutter body having at least one insert pocket, the at least one insert pocket comprising:

adjacent side and rear walls generally transverse to a base, the side wall being provided with two spaced apart generally flat and non-coplanar side support surfaces, a forward side support surface and a rear side support surface, the forward side support surface makes an angle α′ with a normal N′ to a plane P′ passing through the base and the rear side support surface makes an angle β′ with the normal N′, wherein the angle α′ is greater than the angle β′.