＊4-flute is lineup of length of cut expands 2D and 3D（D≧3）. ＊MUGEN COATING PREMIUM Plus realizes long tool life even for hardened steel up to 70HRC. ＊Improved machining accuracy with high rigidity multi-flute design. ＊Shank diameter tolerance，high accuracy type，is - 0.001mm ～ - 0.003mm.