| 摘要 |
A reamer (T) has first cutting edge (3) for finish-machining the inner circumferential surface of a through hole (H) of the work (W), and second and third cutting edges (5, 6), at stepped portions (41, 42) at the end of a small-diameter portion (4) that is formed by cutting the first cutting edge (3), for chamfering first and second opening edges (H1, H2) of the through hole (H), respectively. After finish-machining the inner circumferential surface of the through hole (H) with the first cutting edge (3) by rotating the reamer (T) about its axis (Lt), the first and second opening edges (H1, H2) are chamfered by the second and third cutting edges (5, 6), respectively by moving the reamer (T) along a circle whose center is the axis (Lw) of the through hole (H) and which has a radius r. Therefore the finish-machining and the chamfering of the through hole of the work can be performed with a single reamer.
|
