Highly stiff end mill

摘要

A highly stiff end mill comprising a shank, a plurality of helix cutting edges on the periphery of the end mill, the end mill being characterized in that a radial rake angle of the helix cutting edges in a cross section perpendicular to the longitudinal axis of the end mill is set in the range of -29 DEG to 0 DEG and a core diameter of the end mill is set in the range of 70 to 90% of the outside diameter of the end mill. By selectively determining the negative rake angle in the range described above, this end mill is applicable to hard materials and has general-purpose properties. The improper factors of the end mill, such as increased cutting resistance, can be compensated for by setting the core diameter thereof to the range described above. This end mill is also structured to be able to cut materials with less hardness values as well as hard materials, thereby covering a wide range of applications.