Corner radius end mill

A corner radius end mill configured for rotating about a rotation axis (AR), comprising:

• a shank portion;
• and
• a cutting portion extending from the shank portion and having a diameter (D);
• the cutting portion comprising:
• a helical flute having a helix angle H which fulfills the condition 20°<H<60° and comprising a flute rake surface;
• a cutting tooth comprising a cutting edge which extends adjacent to the flute rake surface, and comprising a corner sector with a corner radius R which fulfills the condition R>0.15D, a first half-sector of the corner sector extending from an imaginary bisection line of the corner sector to a radial tangent point and a second half-sector of the corner sector extending from the imaginary bisection line to an axial tangent point, the first and second half-sectors subtending equal angles about the imaginary bisection line;
• an end gash surface extending adjacent the cutting edge and the flute rake surface;
• and
• a blended gash extending along the cutting edge from a first extremity, and blending the end gash surface and the flute surface;
• the blended gash being spaced from a radial tangent point by a predetermined distance;
• the blended gash extending to a second extremity which is spaced apart from an imaginary axial line and the second half-sector, the imaginary axial line extending from a sector center point to the axial tangent point;
• and
• the second half-sector comprising a traverse sub-sector having a traverse central angle, the traverse sub-sector being distally located from the first half-sector, and wherein the blended gash extends into the second half-sector traversing the traverse sub-sector.