Multi-edge cutting head and an insert used therein

A cutting portion of an integral cutting tool or of a cutting insert adapted for mounting onto a cutting tool holder to form a cutting tool, comprising:

• a plurality n of cutting edges, the cutting portion extending along a cutting path about a central axis, the cutting path passing through a point of each of the cutting edges which is at a maximal radial space R from the central axis, such that
• n
• ≥
• 3
• 
• D
• 4
• ·
• θ
• 360
• ,
• where D=2 γ and θ is the angular extension of the cutting path about the central axis, and such that at any given point along the cutting portion,
• 3
• 
• D
• n
• ≥
• L
• ≥
• 3
• 
• D
• 2
• 
• n
• ,
• where L is one of the following:
• i. the extension of the cutting portion in a direction perpendicular to the cutting path;
• and
• ii. the extension of the cutting edges in a direction substantially perpendicular to the cutting path.
• wherein the cutting insert has a top face and a bottom face and at least one side wall extending therebetween, the cutting portion extending along at least a segment of the at least one side wall, and wherein the cutting insert has a central plane extending between the top face and the bottom face and substantially parallel thereto, the cutting insert including:
• a first cutting portion extending along the segment such that cutting edges thereof extend between the top face and the central plane;
• a second cutting portion including cutting edges extending between the bottom face and the central plane;
• and
• wherein the cutting insert is reversible between a first position in which the first cutting portion is adapted for coming in contact with the workpiece and a second, reversed position in which the second cutting portion is adapted for coming in contact with the workpiece.

A cutting insert, comprising:

• a top face;
• a bottom face;
• and
• at least one side wall extending between the top face and the bottom face;
• wherein the cutting insert extends along at least a segment of the at least one side wall, the cutting insert has a central plane extending between the top face and the bottom face and substantially parallel thereto, the cutting insert including:
• a first cutting portion extending along the segment such that cutting edges thereof extend between the top face and the central plane;
• a second cutting portion including cutting edges extending between the bottom face and the central plane;
• and
• wherein the cutting insert is reversible between a first position in which the first cutting portion is adapted for coming in contact with the workpiece and a second, reversed position in which the second cutting portion is adapted for coming in contact with the workpiece.