Patent ID: 8585329
Filing Date: 2013-11-19
Classification: B23C,Y10T

Abstract:
1. A ball end mill wherein: a plurality of cutting edges are provided on a tip of the ball end mill having curvature; an inner circumference end of a rake face of each of the plurality of the cutting edges is arranged at a position offset forward in rotation direction from a spindle; the inner circumference end of the rake face of each of the plurality of the cutting edges is arranged at a position protruding oppositely to a side at which the cutting edge is formed from the spindle in radial direction for predetermined distance X in each of the cutting edges, a part from an outer circumference end of a ridgeline, which is a boundary between the rake face and a flank of the cutting edge, to a midway of the ridgeline is determined as a main cutting edge; in each of the cutting edges, a part from the midway of the ridgeline to an inner circumference end of the ridgeline is determined as an auxiliary cutting edge; a connecting portion between the main cutting edge and the auxiliary cutting edge in each of the cutting edges is a portion protruding most toward the tip along the axial direction of the spindle; and wherein: 0<X