Patent ID: 8858128

Claim:
A corner radius end mill configured for rotating about a rotation axis (A R ), 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>0.15 D, 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 located in the second half-sector in a direction away from the first half-sector, and blending the end gash surface and the flute rake surface.