REPLACEABLE BLADE EDGE ROTARY CUTTING TOOL AND TOOL BODY

An indexable roughing end mill capable of suppressing generation of chattering is provided. When the positions of cutting inserts (40) arranged in each spiral groove (28) are defined as a first segment to an n th segment (where n is an integer of 2 or higher) from a leading end surface (22) side of a tool body (20) toward a base end surface (21) side, all of the angles (²1...²m (where m is an integer of 2 or higher)) between lines connecting a rotational axis (O) and the cutting inserts (40) in the first segments of the respective spiral grooves (28) are different from each other, as viewed from the leading end surface side of the tool body (20), and an angle (±t) between the cutting insert (40) in the first segment and the cutting insert (40) in the n th segment (the uppermost segment) in a spiral groove 28 is different from any of the angles ²1 ...²m (where m is an integer of 2 or higher) between the lines, as viewed from the leading end surface side of the tool body (20).