| 摘要 |
PURPOSE:To increase the tool rigidity and enable a highly precise working by forming the core thickness circumferential surface, peripheral cutting edge and end cutting edge of an end mill in which the land part is provided projectingly from the core thickness circumferential surface when the radial depth of cut is not less than 0.5mm into particular forms. CONSTITUTION:A core thickness circumferential surface 4 is concentric with the edge end diameter circle, and its diameter D2 is set (0.08-0.99) D1 to the edge top diameter D1 to increase the rigidity. The axial back taper of a peripheral cutting edge 9 is set 0-0.005mm per 30mm, and the radial length L of an end cutting edge 9 is set (0.02-0.10) D1 to the edge end diameter D1, to form a first spacing angle theta1 and a second spacing angle theta2, where theta1<theta2, theta1=30-2 deg., theta2=2-5 deg.. On the cutting face in grinding from the peripheral cutting edge 6 to the core thickness circumferential surface 4, a chip pocket 10 formed in such a manner as to scrap a part of the core thickness circumferential surface is provided, and its maximum depth H is set (0.01-0.11) D1 to the edge end diameter D1. |
