To provide a reamer for precision work for accurately working a stepped hole having a small hole diameter difference.
The reamer 10 for precision work works the stepped hole composed of a plurality of hole diameters. A set of cutting edges composed of a plurality of cutting edges 2 and 3 having a different diameter, are arranged in a plurality at equal intervals in the peripheral direction of the reamer 10. The respective cutting edges 2 and 3 of the set of the cutting edges extend in parallel to a longitudinal shaft of the reamer 10 by mutually separating in the peripheral direction of the reamer 10, and are arranged so that a diameter of the cutting edges 2 and 3 becomes small toward the front side in the rotational direction of the reamer 10 and the tip side of the reamer 10, and a diameter of the cutting edges 2 and 3 becomes large toward the rear side in the rotational direction of the reamer 10, and the base end side of the reamer 10.
KUMAGAI TAKANARI
NAGAI YOSHIO
Jun Tsuruta
Masaya Nishiyama