A rotary cutting tool with a longitudinal axis includes a shank portion and a cutting portion defining a length of cut. The cutting portion includes a plurality of blades separated by flutes extending along the length of cut. A first blade forms a first helix angle with respect to the longitudinal axis at the cutting tip. A second blade adjacent the first blade forms a second, different helix angle with respect to the longitudinal axis at the cutting tip. The cutting edge of the first blade is formed at a first distance with respect to the cutting edge of the second blade. A helix angle of at least one of the plurality of blades varies along the length of cut and a distance between cutting edges of the first and second blades varies along the length of cut.