BALL END MILL

摘要

This aims to provide a ball end mill capable of preventing the occurrence of a 'pluck' off a work face. The ball end mill (10) is equipped with two cutting edges (11 and 12) formed at its spherical tips. The rake face (11a) of the cutting edge (11) has its inner circumference end arranged at a position offset farther forward of a rotating direction than a spindle. The rake face (11a) of the cutting edge (11) has its inner circumference end arranged at a position protruding by a predetermined distance from the spindle to the opposite side of the cutting edge forming side in the radial direction. The portion of the cutting edge (11) from a connecting portion (11f), which is formed midway of a ridgeline (11c) or a boundary line between the rake face (11a) of the cutting edge (11) and a flank (11b), to the outer circumference end of the cutting edge (11) is a main cutting edge (11m). The portion of the cutting edge (11) from the connecting portion (11f) to the inner circumference end of the cutting edge (11) is an auxiliary cutting edge (11s). The connecting portion (11f) of the cutting edge (11) is the portion which protrudes the farthest in the cutting edge (11) to the tip side of the spindle in the axial direction. The cutting edge (12) is constituted like the cutting edge (11).