Rotary cutting tool having a predetermined number of left and right handed helical flutes and end face cutting teeth

A rotary cutting tool (20), having a longitudinal axis (A) about which the rotary cutting tool (20) is rotatable in a direction of rotation (R), the rotary cutting tool (20) comprising:

• a cutting portion (22) and a mounting portion (24) extending therefrom, the cutting portion (22) comprising:
• an end face surface (28), intersected by the longitudinal axis (A), and a peripheral surface (30) extending from the end face surface (28) towards the mounting portion (24), the peripheral surface (30) comprising respective pluralities of main and auxiliary flutes (32, 34) recessed therein that extend helically with opposite hand about the longitudinal axis (A);
• a plurality of end face cutting teeth (48) formed on the end face surface (28), each end face cutting tooth (48) comprising an end tooth major surface (54) that generally faces the direction of rotation (R), and an end cutting edge (56) formed at the intersection of the end face surface (28) and the end tooth major surface (54), each end face cutting tooth (48) being defined between circumferentially adjacent end gashes (42), each of which end gashes (42) interrupts an intersection of the peripheral surface (30) with the end face surface (28) at an associated one of the plurality of main flutes (32);
• wherein
• the number of main flutes (32) and auxiliary flutes (34) are different, each being wholly divisible by, and greater than, the number of end face cutting teeth (48);
• the end gashes (42) are evenly circumferentially distributed with respect to the main flutes (32);
• and
• in each cross sectional view of the cutting portion (22), taken perpendicular to the longitudinal axis (A) through the end gashes (42), an imaginary contour line (LC) defined by a peripheral contour (PC) of the peripheral surface (30) of one of the end face cutting teeth (48) is in rotationally aligned relationship, about the longitudinal axis (A), with the peripheral contour (PC) of the peripheral surfaces (30) of all other end face cutting teeth (48).