An end mill for machining titanium, having a longitudinally extending rotation axis A R and comprising: a shank portion, and a cutting portion extending from the shank portion to a cutting end face and being integrally formed with at least four cutting teeth alternated with helically shaped flutes and having a cutting portion diameter D E; each tooth comprising a rake surface, a relief surface, a cutting edge formed at an intersection of the rake and relief surfaces (28, 26), and a relief edge spaced apart from the cutting edge and formed at an intersection of the relief surface and an adjacent surface of the flute succeeding the tooth each rake surface comprising a rake recessed sub-surface, a rake cutting sub-surface positioned further than the rake recessed sub-surface from the rotation axis (A R) and raised above the rake recessed sub-surface, relative to an imaginary radial line (L R) passing through the cutting edge, and a rake discontinuity formed at an intersection of the rake recessed and rake cutting sub-surfaces (48, 50); characterized in that each tooth comprises an actual internal cutting angle (γ) formed at an intersection of the rake cutting sub-surface and the relief surface, the actual internal cutting angle (γ) having a greater value than an imaginary internal cutting angle (λ) formed at an intersection of imaginary extension lines of the rake recessed sub-surface and the relief surface; wherein each tooth has a rake cutting sub-surface length dimension L C, measured from the rake discontinuity thereof to the cutting edge thereof, fulfilling the condition 0.01R T < L C < 0.05R T, wherein R T is the tooth's radius dimension, measured in a straight line from the rotation axis (A R) to the cutting edge; wherein each tooth has a radial rake angle (β) within a range of 6° to -6°; wherein each flute has a helix angle H which fulfills the condition 30° < H < 50°; wherein, in a plane perpendicular to the rotation axis A R, each flute comprises a convexly shaped ejecting portion and a concavely shaped bending portion connecting the ejecting portion and the rake recessed sub-surface; wherein the ejecting portion has an ejection height E which is measurable between an apex of the ejecting portion to an imaginary straight line (I L) extending from a nadir N of the adjacent bending portion to the adjacent relief edge 32, the ejection height E having a magnitude fulfilling the condition 0.010D E < E < 0.031D E; and wherein, at the cutting end face, index angles of the flutes are in an asymmetric arrangement. a shank portion, and a cutting portion extending from the shank portion to a cutting end face and being integrally formed with at least four cutting teeth alternated with helically shaped flutes and having a cutting portion diameter D E; a rake surface, a relief surface, a cutting edge formed at an intersection of the rake and relief surfaces (28, 26), and a relief edge spaced apart from the cutting edge and formed at an intersection of the relief surface and an adjacent surface of the flute succeeding the tooth a rake recessed sub-surface, a rake cutting sub-surface positioned further than the rake recessed sub-surface from the rotation axis (A R) and raised above the rake recessed sub-surface, relative to an imaginary radial line (L R) passing through the cutting edge, and a rake discontinuity formed at an intersection of the rake recessed and rake cutting sub-surfaces (48, 50);