Abstract: A rotary cutting tool of the type comprising an elongated cylindrical body having a central axis about which it is rotated for performing cutting or material removal operations during relative movement in directions perpendicular to its axis of rotation. The body includes a shank end portion and a cutting end portion. The cutting end portion includes a plurality of generally continuous cutting edges lying at a uniform radial distance from the axis and extending in generally parallel helical paths about the body. Each of the cutting edges is preferably of generally sinusoidal configuration along its respective helical path with spaced portions of each edge having alternating positive and negative radial rake.