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. A third blade adjacent the second blade forms a third, different helix angle with respect to the longitudinal axis at the cutting tip. The first, second and third helix angles deviate by at least 2 degrees. The cutting edges of the first, second and third blades have unequal indexing.