Multi-flute endmill

A multi-flute endmill comprising:

• a cutting edge part that has a plurality of cutting edges, each formed with an end cutting edge which is formed at a tip of a shank from a side of a rotation axis O to a peripheral side in a radial direction of the shank, a corner R edge continuous to the end cutting edge and a peripheral cutting edge continuous to the corner R edge;
• and
• a gash and a flute that are respectively formed on a center side and the peripheral side in the radial direction between the adjacent cutting edges in a rotation direction R around the rotation axis O,
• wherein a rake face of the cutting edge is formed, from the center side to the peripheral side in the radial direction, with:
• a rake face of the end cutting edge;
• and
• a rake face of the peripheral cutting edge that is adjacent to the rake face of the end cutting edge, that forms a face different from the rake face of the end cutting edge and that also serves as a rake face of the corner R edge,
• a flank face of the cutting edge is formed, from the center side to the peripheral side in the radial direction, with:
• a flank face of the end cutting edge;
• a flank face of the corner R edge adjacent to the flank face of the bottom end cutting edge;
• and
• a flank face of the peripheral cutting edge adjacent to the flank face of the corner R edge,
• the flute is formed with:
• the rake face of the peripheral cutting edge;
• a flute face opposite the rake face of the peripheral cutting edge on a forward side in the rotation direction R;
• and
• a bottom surface formed in a boundary between the rake face of the peripheral cutting edge and the flute face;
• and
• an intersection between a convex ridge line located in a boundary between the rake face of the end cutting edge and the rake face of the peripheral cutting edge and a convex ridge line located in a boundary between the rake face of the end cutting edge and a bottom surface of the flute is moved into the center side of the radial direction than a boundary between a flank face of the corner R edge and a flank face of the end cutting edge.