| 摘要 |
<p>Provided is an end mill having a gash capable of ensuring excellent chip discharge performance and of preventing stress concentration, without losing the rigidity of a top portion of an end mill body.
In a cross-section perpendicular to an intersecting ridgeline between an end cutting edge rake face (6A) and a gash bottom face (6B) of a gash (6), the gash bottom face (6B) and the end cutting edge rake face (6A), and the gash bottom face (6B) and the gash wall face (6C) are respectively connected together by first and second connecting faces (8A and 8B). In the cross-section, these connecting faces have a form which is a concave curve or a substantially concave curve formed with straight lines. The radius of curvature (R1) of the concave curve or the radius of a circle inscribed in the straight lines forming the substantially concave curve about the first connecting face (8A) is larger than the radius of curvature (r1) of the concave curve or the radius of a circle inscribed in the straight lines forming the substantially concave curve about the second connecting face (8B).</p> |
