A milling cutter includes a shank portion and a cutting portion having a cylindrical outer surface. The milling cutter includes a plurality of major cutting edges extending from an end face toward the shank portion, and a plurality of minor cutting edges disposed at the end face of the cutting portion. A relief surface is formed in the cylindrical outer surface proximate a corner of the milling cutter such that the primary cutting edges forms an angle equal to 90 with respect to the end face of the milling cutter. As a result, the milling cutter is capable of cutting a perfect 90 shoulder in a workpiece.

The present invention is aimed to provide a carbon fiber reinforced resin processed product which is almost free from the problems described above on a processed surface subjected to cutting or the like and has an end surface where generation of a burr is suppressed, has favorable surface properties, and surface nature, and particularly smoothness is excellent; and provides a carbon fiber reinforced resin processed product having an end surface which has fibers and a resin, wherein the end surface has a surface roughness (Rz) within a range from 5 m to 50 m.

A multi-flute endmill including a cutting edge part having multiple cutting edges and flutes formed between adjacent cutting edges in a rotation direction around the tool axis O. A rake face of each cutting edge is formed from a rake face of an end cutting edge from the tool axis O side to the outer peripheral side of a shank, an adjacent rake face of a corner R edge that forms a surface different from the rake face of the end cutting edge, and an adjacent rake face of a peripheral cutting edge that forms a surface different from the rake face of the corner R edge. A gash is formed between the rake face of the end cutting edge and a flank of an end cutting edge that is adjacent on a forward side thereof in the rotation direction R.