Patent ID: 6761510
Filing Date: 2004-07-13
Classification: B23B,Y10T

Abstract:
A cutting tool comprising:a curved cutting edge at a nose; a pair of straight cutting edges between which the nose is located; and a chamfer extending along the curved cutting edge and the straight cutting edges; wherein the chamfer increases in width from a place located at or adjacent a junction of the curved cutting edge and one of the straight cutting edges to a junction of the curved cutting edge and the other of the straight cutting edges and reduces in width at the junction of the curved cutting edge and the other of the straight cutting edges when observed in plan; and wherein a minimum value of the width of the chamfer is 0.2 mm or smaller and a maximum value of the width of the chamfer ranges from 0.05 mm to 0.5 mm; wherein W2/W1&gE;1.5 where W1 is a minimum value of the width of the chamfer and W2 is a maximum value of the width of the chamfer.