| 摘要 |
PURPOSE:To cut a cylindrical surface with high accuracy using no special cutting machine by a construction wherein a plurality of bits symmetrical about a center axis are formed at the end of a tubular shank, and the bits comprise a bite face substantially parallel to the plane passing the center axis and a flank having a necking slope relative to the plane perpendicular to the center axis. CONSTITUTION:A shank part (b) is attached to the chuck of a driller or the rotatable section of a lathe. With the shank part being fed in a similar way to drilling, a material 7 to be cut is cut with bits 5-1, 5-2 to form the cylindrical surface of diameter D. The part of the cylindrical surface of diameter D and a land (i) are fitted with each other in a sliding relation to hold the center axes of the cut material 7 and cutting tool in a concentric state. Because the cut material 7 is cut by two bits 5-1, 5-2 symmetrical about the center axis (d) simultaneously, there causes no bending deformation. |
