Rotary cutting tool having corrugated cutting edge portion whose pitch and /or depth are/is increased with increase in diameter of body of the cutting tool

A rotary cutting tool which is to be rotated about an axis thereof for cutting a workpiece, including: a generally cylindrical body portion having (a) at least one flute each of which is formed in the cylindrical body portion and each of which extends from an axially distal end of the cylindrical body portion toward an axially proximal end of the cylindrical body portion, and (b) at least one cutting edge each of which is provided by one of widthwise opposite edges of the flute, wherein each of at least one cutting edge includes a corrugated edge portion having a corrugated shape, and wherein at least one of a pitch and a depth of the corrugated shape is increased with an increase in a diameter of the cylindrical body portion whose outer circumferential surface is defined by a rotary trajectory of an envelope passing through crests of the corrugated shape.